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General Biology II

by: Einar Sanford

General Biology II BIOL 1120

Einar Sanford

GPA 3.84

Robert Reeder

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Robert Reeder
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This 30 page Class Notes was uploaded by Einar Sanford on Thursday October 15, 2015. The Class Notes belongs to BIOL 1120 at Motlow State Community College taught by Robert Reeder in Fall. Since its upload, it has received 30 views. For similar materials see /class/223574/biol-1120-motlow-state-community-college in Biology at Motlow State Community College.


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Date Created: 10/15/15
BIOL l 120 REEDER CHARACTERISTICS OF THE ANIMAL IGNGDOM I Characteristics true multicellular eukaryotic lacking cell wall plastids and photosynthetic pigments heterotrophic and motile at some stage in their life cyc e A Presence or Absence of Backbone l Invertebrates lacking a supportive and protective backbone majority of animals 97 of all animals 2 Vertebrates segmented internal endoskeleton composed of cartilage or bone39 only one subphylum Vertebrata of the phylum chordata contains all the vertebrates B Body Symmetry l Asymmetrical body not divisible equally into parts some Porifera 2 Symmetrical divisible into equal parts a Radial symmetry multiple planes through the central body longitudinal axis will divide the animal into radial sectors as in pie pieces or can be divided into similar halves by more than two planes passing through the longitudinal axis tubular vase or bowl shapes in which one end of the longitudinal axis is the mouth 1 body parts arranged around a central axis so that stimuli is received from all directions equally 2 organism has a top and a bottom 3 suitable for sedentary or sessile life style some Porifera Cnidaria Echinoderms b Bilateral symmetry sagittal plane down length of animal through its midline divides the animal into equal and opposite halves or mirror images suitable for active movement 2 many show cephalization definite heads with concentrations of sensory structures on anterior end of their body which is better fitted for directional movement 3 most of the other phyla such as Chordates Annelids 4 Related anatomical terminology for lower animals most animals with longitudinal axis parallel to the earth s surface majority are guadrupeds a Anterior part that moves forward usually contains mouth b Posterior opposite side or end to anterior39 end equipped with tail for swimming or that follows c Dorsal back or upper surface d Ventral belly or under surface 5 For humans bipeds anterior is synonymous with ventral and posterior implies the same as dorsal superior and inferior ends 3 longitudinal plane down the organism39s length 4 transverse plane cross section perpendicular to the longitudinal axis of an organism C Body Spaces or Cavities l Acoelomata lacking a body space outside the gut39 Nemertea and Platyhelminthes 2 EuCoelomata having a quottruequot body cavity or coelom space between the gut and the body wall formed within the mesoderm and lined by a mesoderm al derived membrane mesenteria andor peritoneum usually with excretory and reproductive ducts leading to the exterior39 characteristic of the higher phyla Mollusca through Chordata with variations limitations in space size amp lining a Variations l Pseudocoel unlined coelom that develops between the mesoderm and endoderm and is filled with uid Nematoda and Rotifera 2 Hemocoel greatly reduced coelom with blood circulating in some or no vessels and instead in spaces between the internal organs Mollusca Arthropoda39 called a quotblood cavity b The pseudocoelom hemocoel and larger spacious true coelom may all function as a quothydrostatic skeleton 3 Significance ofa coelom a limitations of a solid body as in flatworms a solid worm has no internal circulatory and may not have a digestive system39 all of its internal organs are pressed on by muscles and are deformed by muscular activity b By possessing a coelom the body39s organs may be located within a lined enclosure where they can function without having to resist muscular pressures especially circulatory digestive and reproductive organs greater body flexibility and permits a greater size and complexity l Digestive tract may move food independently of body movement 2 coelom may act as a hydrostatic skeleton assists support circulation respiration and excretion 3 pumping of heart for greater circulatory efficiency 4 enlargement of female abdominal area during pregnancy and breeding39 allow for gametes to accumulate 4 True coelomates include Mollusca Annelida Arthropods Echinoderms and Chordates biol lZchharacteristics animal kingdomdoc 11808 D Digestive Tract Type or Gut and related Body plan 1 m digestive tract with m body plan Porifera utilize specialized cells via pores amp a filter feeding process 2 Incomplete mouth only quotsac body plan Coelenterates Cnidaria Platyhelminthes 3 Complete mouth and anus quottube within a tubequot all other phyla allows for greater digestive specialization E Embryonic Developmental Stages sometime after emergence of bilateral body plans two key evolutionary groups opened up 1 zygote fertilized egg undergoes a series of mitotic divisions cleavage eventually forming an embryonic stage called the blastula many celled stage with fluidfilled cavity 2 In most higher animals the blastula folds inward at one point ultimately resulting in an opening at one end of a forming tube called the blastopore 3 Developmental stage called the gastrula will next form whose development is significant to the evolutionary phyla relationships of higher animals and their advancement 4 Classification will be based on the result of blastopore differentiation the cleavage first several divisions of the embryo pattern and the cleavage type a Protostomes l Blastopore becomes the mouth of the digestive tube 2 Spiral cleavage pattern spiral arrangement of cells resulting from the initial cell divisions that occur obliquely to the polar axis any one cell is located between two cells above or below it 3 Fate of each embryonic cell is fixed early determinate cleavage 4 In most of the mollusks annelids and arthropods possibly some flatworms b Deuterostomes Blastopore becomes the anus of the digestive tube 2 Radial cleavage pattern cells located directly above or below one another resulting from early divisions which are either parallel or at right angles to the polar axis cells are located directly above or below one another stacked in layers 3 Each early embryonic cell has the potential to develop into an entire organism indeterminate cleavage 4 In echinoderms and chordates F Embryonic Development Concerning Number of Germ Layers gastrulation relates to the potential for tissue development and in turn more complex development organs organ systems a tissue consists of a few types of closely associated cells adapted to carry out specific functions 1 Classification a No tissue development Porifera b Diploblastic 2 layers ectoderm and endoderm Coelenterates or cnidarians represent the lowest phylum with tissue forming capability c Triploblastic 3 layers ectoderm endoderm mesoderm Platyhelminthes and all higher phyla 2 Germ layers allow for greater cell specialization division of labor a Ectoderm skin sense organs nerve system and specific glandular epithelium pineal pituitary and adrenal medulla b Mesoderm muscles circulatory system reproductive system excretory system skeletal system glandular epithelium c Endoderm epithelium of the digestive tract and the respiratory tract glandular epithelium thyroid parathyroid pancreas and thymus G Bodily Support to a True Skeletal System 1 Hydrostatic skeleton any fluidfilled body cellular space andor cavity pseudocoelom or coelom which helps support the body wall and offer resistance and support by which muscular contraction can occur it transmits force when contractile cells contract against it coelenterates and annelids assists circulation respiration and excretion as well a Because fluids cannot be compressed force is transmitted through the fluid causing change in shape and movement of the bod b Works something like a balloon filled with water c Primary examples cnidarians and anneli s d Also supplemental in complex invertebrates with shells or an endoskeleton clam s foot sea star s and sea urchin s tube feet the penis copulatory organ r V 2 Exoskeleton external framework typically composed of calcium carbonate CaCo3 lime such as in the corals clams and snails or chitin in the arthropods crab insects lobster 3 Endoskeleton internal framework of siliceous spicules and the protein spongin as in sponges g of cartilage andor bone in the chordates sharks birds reptiles fishes hum ans g Cva in starfish 4 The exoskeletons of mollusks and arthropods are nonliving while the endoskeleton of vertebrates represents living tissue biol lZOpcharacteristics animal kingdomdoc 11808 H Segmentation or Metam erism l Implies a linear repetition of body parts internally andor externally with each repeated unit termed generally a somite underlies the organization of all advanced animals built in redundancy as a safety factor Examples a In earthworms externally has successive somites as well as internally the repetitive arrangement of organs and systems digestive tract and the partitioning off of segments b In crayfish and insects externally three distinct body regions head thorax abdomen in some the segments may be fuse c In chordates and man internally vertebral column body muscles and nerve pathways I Possessing External Appendages for Locomotion Feeding etc 1 Examples a Tentacles of sea anemone jellyfish Hydra minute setae of earthworms legs pincers swimmerets of arthropods fins legs and wings of vertebrates I Reproduction 1 Sexual reproduction is the general rule for animals meiosis occurs in the gonads producing nonmotile eggs and agellated sperm may be external or internal fertilization zygote passes through a series of embryonic stages resulting in an immature form or larvae a animals are mainly diploid organisms with gametes the only haploid cells in their life cycles 2 Types a Monoecious or hermaphroditic individual animal contains both male and fem ale sex organs some Poriferans Coelenterates atworms earthworms and leeches b Dioecious separate and distinct sexes most of the higher phyla 3 some asexual examples typically for regeneration of a lost body part sponges lizard39s tail starfish arm but may be for production of new individual sponge farming budding in the hydra K Circulatory System mechanisms to supply or transport materials gases nutrients wastes advancement requires 1 blood 2 heart for pumping 3 system of vessels or spaces to circulate the hydrostatic skeleton assists transport in lower forms 1 m specialized circulatory structures present in sponges cnidarians atworms or nematodes hydrostatic skeleton assists a Tissues are bathed in uid laden with oxygen amp nutrients in aquatic forms b Wastes simply diffuse into the uid and are washed away Types a Qpen the heart pumps blood via vessels into the body cavity portions or sinuses so as to bathe the internal organs and then may return the blood to the heart via ostia equipped with valves as in insects or blood passes into open ended vessels that lead to the gills and then to vessels back to the heart as in mollusks l Hemocoel blood filled sinuses types Insects mollusks snail clam crayfish crab 2 Sluggish inefficient movement colorless blood no respiratory pigment in many 3 In the clam blood is pumped both forward and backward by the heart b Closed blood is always contained within blood vessels interstitial uid is separate from the blood typically hemoglobin as the respiratory pigment 1 Quick responses because blood can be supplied on demand to the needing tissue skeletal muscle 2 Presence of a respiratory pigment aids gas transfer L Respiration Organism ic and Cellular 1 Four specializations for the exchange of gases a Integumentag Exchange body surface for exchange diffusion of gases hydrostatic skeleton and usually with no circulatory system Porifera Coelenterata Platyhelminthes Nematoda Anne i l Supplements breathing by means of gills and lungs in certain vertebrates amphibians fishes 2 lower metabolic rate requires smaller quantities of oxygen b moist outgrowths of the body surface that are exposed to water starfish clam crayfish amphibians fishes each gill consists of many filaments containing blood vessels c Tracheal System network of air tubes found in insects and other terrestrial arthropods which open externally via tiny holes spiracles on the body surface leading to all parts of the body terminating in uidfilled tracheoles d Lungs most terrestrial animals have surface ingrowths or from the wall of a body cavity protected from desiccation highly vascularized so that the circulatory system assists the transfer of gases typically utilizing a respiratory pigment plus muscle system assistance ventilation vertebrates contain a series of air passageways terminating in thinwalled air sacs alveoli N 19 biol lZOicharacteristics animal kingdomdoc 11808 BIOL 1120 REEDER CONTROL OF THE REPRODUCTIVE PROCESS 1 Control of the Female Reproductive Cycle A Neural and Hormonal Control bio I lZOicontrolireproductive doc Hypothalamus neurosecretory tissue deep in the brain secretes a releasing hormone initially at puberty and then cyclic throughout female s reproduction life that stimulates the pituitary M branches off the hypothalamus deep in the brain to secrete follicle stimulating hormone initially and E luteinizing hormone later in stages of the menstrual cycle a M induces one or more primary follicles of both ovaries to begin maturing oogenesis meiotic development of potential ova and stimulates follicular cells of the ovaries to secrete estrogens l Oogenesis a Diploid oogonia egg mother cell mitotically proliferate during prenatal development at about the third month oogonia develop into larger diploid cells called primary oocytes located within primary follicles 500000 total at birth arrested in Prophase I at birth With beginning puberty and continuing of each menstrual cycle Meiosis is stimulated resulting in the eventual singling out of E of several secondary follicles from one ovary to reach maturity due to hormonal in uence usually several follicles are stimulated from both ovaries but only one attains maturity ovulates Normally only one functional cell potentially fertilizable out of four of E ovary will be ovulated per menstrual cycle period of a female prima follicles become secondary follicles of which one becomes a Graa an follicle that ovulates Reproductive capability m relatively early in female s life average age in the 40 s and termed menopause due to the absence of hormonal stimulation The human egg is approximately 01mm in diameter and barely visible to the unaided 6 V c d V 6 Estrogens will be signi cant in the rst half of the menstrual cycle and other features mentioned later in pregnancy and birth to in uence the females uterine lining endometrium to begin its increased thickening and vascularization b E its increased release results in ovulation secondary oocyte and polar body release from a Graa an follicle and formation of the corpus luteum ruptured follicle of one ovary becomes a large yellow body capable of secreting progesterone l Progesterone gestatory hormone will be signi cant in the latter half of the menstrual cycle as well as during pregnancy to continue estrogens preparation and maintenance of the endometrial lining in anticipation of receiving for implantation a fertilized egg pregnancy Placental Hormones includes progesterone and estrogens a Normal qualities of these hormones are secreted by the follicle cells and the corpus luteum and are adequate to initiate implantation zygote to endometrium if fertilization occurs sperm egg singlecelled ygote b Once implantation has occurred there is a need for these hormones in much higher concentrations The placenta once formed begins secreting large quantities of estrogens as much as 300 times the quantity supplied by follicle cells the estrogens continue to in uence the endometrium and more importantly aids in the enlargement of the breasts and the eXternal genitalia d Progesterone secretion is also carried on at an elevated rate by the placenta it aids continuing endometrium development during early stages of pregnancy and also inhibits uterine contractions that might otherwise eXpel the fetus inhibits oxytocin from posterior pituitary prematurely At birth the sudden drop in estrogen and progesterone concentrations in the maternal bloodstream removes the inhibiting affect on the hormone prolactin and permits its secretion from the anterior pituitary thereby stimulating the production of milk by the mammary gland lactation 2 V C 6 22409 B The Menstrual Cycle 1 The uctuations of individual hormone concentrations in the bloodstream produces cyclic structural and functional changes in the female reproductive organs pituitary and ovarian hormones affect endometriumreferred to as the menstrual cycle Normal series of this cycle begins at puberty at intervals of 25 to 35 days except when pregnancy and lactation intervene it continues for 35 to 40 years until there is cessation of reproductive capability menopause cycle is approximately 28 days duration Uterus is not in perpetual readiness to receive a fertilized egg but must undergo structural changes so that it can effectively accept the fertilized egg and nourish the fetus First day of the cycle is usually timed with beginning of menstruation and continues until beginning of neXt menstrual period menstruation refers to endometrium deterioration and the bleeding that occurs Essential purpose of the menstrual cycle is to bring about the release of ova and to prepare the uterus for its acceptance of a fertilized egg if fertilized egg is not available after the preparation phase reduced hormone levels cause the endometrium to degrade and then preparation stages all over again if pregnancy occurs the endometrium is in uenced by hormones to maintain its state of preparedness culminating in the formation of placental tissues that nourish the fetus A typical menstrual cycle can be described in 3 broad phases Menstrual m proliferative g follicular ph and the luteal g secretogy ph a Menstrual Phase 1 Characterized shedding of the endometrium resulting in the discharge of bloody uid discharge consists of epithelial cells mucus interstitial uid and about 25 to 65 ml of blood and the microscopic unfertilized now dead ovum Although menstruation actually is the terminal event of each cycle it is the time most easily xed by any woman thus the rst day of the menstrual ow is said to be the rst day of the menstrual cycle ow may last one to eight days with average duration four to siX days the degeneration of the endometrium is a progressive one involving only one small area at a time Ovarian activity in this phase involves beginning growth and development of several primary follicles 2025 primary follicles are stimulated each time of both ovaries under in uence of M usually only one follicle is selected for ultimate maturation rising blood concentration of estrogen amp progesterone further inhibit maturation of other follicles Proliferative Phase Associated with a rapidly growing ovarian follicle and the production of estrogen by cells surrounding the follicle Activities depend on a miXture of FSH and LH where FSH predominates initially Estrogen induces endometrium to become highly vascular and thickened These activities occur from fourth to thirteenth day of a 28 day cycle The rising estrogen causes a sharp shift in the FSHLH mixture inhibiting FSH secretion and increasing LH secretion The end of the proliferative phase coincides with the release of egg immature ova or secondary oocyte from the Graa an follicle Ovulation at about the amp day of the cycle 36 hours after surge of LH ovulation occurs a Normally only one secondary follicle of one ovary is singled out by the estrogens for ultimate ovulation and eventual maturing if fertilized b Rising blood concentrations of estrogen and progesterone will further inhibit the maturation of other follicles Secretory Phase 1 Following ovulation LH stimulates development of the corpus luteum and the secretion of progesterone progesterone continues and accelerates the work begun by estrogencontinued thickening of endometrium becoming more vascular and developing specialized glandular cells that provide nutrient substances in anticipation for a fertilized egg these changes are maXimal about one week after ovulation If fertilization does not occur in the fallopian tubes the rising progesterone and estrogen tide serves to inhibit the secretion of LH negative feedback Equot W 5 U 9 57 as uth w M VVVV V V 6 V 0 N V biol l207controlyreproductivedoc 22409 a Result is the corpus luteum degenerates the hormone level and menstruation occurs endometrium is deprived of hormonal stimulation corpus luteum lasts about 2 weeks if fertilization doesn t occur If fertilization occurs and the fertilized ovum is implanted in the uterus the corpus luteum continues to secrete progesterone gestatory hormone for about three months this is possible due to chorionic gonadotropin prod by developing embryonic tissues which serves to maintain the corpus luteum until the embryonic tissues and placenta are capable of producing progesterone and estrogen on their own C Fertilization and Further Development 1 Processes a Fertilization consists of the penetration of a secondary oocyte by a spermatozoan usually approx ZOO2000 arrive in the ovum vicinity and must remain in the female genital tract 4 to 6 hours before they are capable of fertilizing which initiates the nal meiotic division resulting in two smaller polar bodies and the M mature fertilized diploid ovum W V b Although millions of spermatozoa are deposited in the vagina only one effects fertilization of one ovum the others disintegrate l Sperm can survive in female for approximately 4872 hours 2 Fertilization however must occur within a hours m ovulation because the ovum m i viabiliLy beyond this time frame 3 Fertilization usually takes place in the M M of the uterine tube 4 Once a sperm has united with an egg chemical and physical changes occur in the egg membrane prohibiting entry of other sperm 5 Fertilized egg now has 46 chromosomes 23 from egg 23 from sperm diploid number is restored oogenesis is completed as well second meiotic division is completed 01mm in diameter c Once fertilization has been accomplished mitosis is initiated2 cells4 cells8 cellsand so on via a process called cleavage also begins emb onic development rst two months 1 Once cell division begins the dividing structure is referred to as the ygote 24 hours to reach 2cell stage successive divisions take less time 2 Zygote has no motile power of its own and is carried along the fallopian tube by muscular contraction and cilia toward the uterus trip takes one to three days 3 By the third day cleavage has resulted in a solid mass of undifferentiated cells called a morula 4 Morula eXperiences a migration of eXtemal cells inward producing a blastopore and a tubular passageway plus an internal uid lled cavity 5 This uid lled ball of cells blastocyst is ready to implant in 7 to 10 days into the endometrium implantation area of maternal endometrium where blastocyst implants is the decidua basalis a On contact to the endometrium the blastocyst produce enzymes that break down the lining epithelium allowing it to sink into the endometrium By the eleventh or twelfth day the blastocyst totally buried has eroded through capillary and arteriole walls releasing blood that bathes the embryo Initially the minute embryo derives nourishment by diffusion from the surrounding blood Through the processes of implantation rapid changes are brought about in the endometrium and embryonic tissues culminating in the formation of the placenta will ultimately assume the exchange tasks begins approximately 7th to 8th day of gestation and is complete by the 3rd month or 10 weeks functioning by 25th day viviparous pattern 1 Placenta is derived from both maternal and embryonic tissues a Deciduae maternal tissue b Chorion embryonic membrane The blood systems of the mother and embryo are physically separate although small amounts may regularly escape and they lie side by side ngerlike projections that are highly vascularized from the chorion are immersed in blood pools of the mother s uterine tissue V b V C F V N V biol l207controlireproductivedoc 22409 BIOL 1120 Reeder THE TRACHEOPHYTES I THE SEEDLESS VASCULAR PLANTS Ferns and Fern allies evolved approximately 420 million years ago Phylum Pterophyta l Ferns a Characteristics that distinguish the ferns from the other lower seedless vascular plants 1 Leaf structure large compound branching leaves fronds that develop by uncoiling fiddleheadsquot for some ferns 2 Stem anatomy contains m a quotpackingquot tissue that also occurs in seed plants 3 Location of sporangia borne on the fronds in clusters called m pl 4 Pattern of development the sporophyte becomes the conspicuous independent plant body developing from the gametophyte and is considered dominant due to its large size and persistance for extended time period the gam etophyte dies soon after reproducing 5 Onlv the sporophyte has vascular tissue while the gam etophyte lacks it 6 Sporic life cycle primarily homosporous with some heterosporous examples b Widely distributed in both the tropics and temperate regions damp and shady places c Temperatezone ferns have horizontal asexual underground stems called rhizomes usually perennial growing on or just beneath the surface of the soil from which grow hairlike roots and fronds d The leafy frond sporophyte becomes independent of the flat green photosynthetic heartshaped prothallus gametophyte which grows flat against the ground 1 2 3 6 B Phylum Psilo l Whisk ferns simplest vascular plants only two species remainin Sporophyte lacks true root and leaves but have vascularized stems serves as the photosynthetic organ a b c e C Phylum Sphe l 1 The prothallus lacks vascular tissue and has tiny rootlike rhizoids for anchoring The prothallus produces archegonia and antheridia on its underside The gametophyte generation can survive only where there is plenty of moisture and shade and the union of eggs and sperm in fertilization requires a water medium compensated for by heavy reliance on asexual reproduction in many species A diploid zygote mitotically divides forming a multicellular embro sporophyte while still attached to and dependent on the gametophyte The diploid fern sporophyte has conducting and supporting tissues amp is eventually nutritionally independent of the gametophyte although initially the sporophyte is parasitic on the gametophyte until it develops its own roots stem and leaves The prothallus withers and dies tophyta Do have horizontal underground rhizomes Dichotomous branching primitive characteristic occurring whenever the stem forks or branches it always divides into two equal halves in contrast when most plant stems branch one stem is more vigo rous becoming the main trunk Tiny round sporangia are found on its aerial stems d Prothalli gam etophyte grow underground where they symbiotically depend on fungi Most species are extinct with those surviving found in the tropic and subtropics nophyta Arthrophyta Horsetails most species are extinct with only a single genus Eguisetum 20 species surviving today Were the dominant plants 300 million years ago and grew as large as modern trees Fossilized remains together with those of other plants are the major source of presentday coal deposits Carboniferous Period Present day species the quotscouring rushesquot are widespread from the tropics to the Arctic on all continents except Australia grow mostly in wet marshy habitats Structure 1 a b e 2 3 4 5 Sporophyte usually less than 40 cm tall with true roots stems and small leaves Multiplebranched bushy structure of many species resembles a horse39s tail Deposits of silica in the epidermis give the plants a harsh abrasive quality Stems have conspicuous nodes that divide them into jointed sections a At each node there is a circlet or whorl of smaller secondary branches and a whorl of small scalelike leaves Some branches develop a conelike structure strobilus at their tip bearing spore sacs Homosporous type with the sporophyte dominating the sporic life cycle bio I lZOitrache ophytes 31805 BIOL 1120 REEDER ANATOMY OF THE HUlVIAN REPRODUCTIVE SYSTEM 1 MALE REPRODUCTIVE SYSTEM A Anatomy 1 Male reproductive organs include paired testes which produce sperm a system of ducts e idid mis w deferens ejaculatog ducts and the urethra which carries sperm out of the body and is both excretory and reproductive in function in the male and the m the male copulatory organ associated with the sperm ducts are accessory structures seminal vesicles prostate gm and bulbourethral g or Cowper39s gland that contribute secretions which together with sperm constitute a thick uid called semen 2 Testes are suspended in saclike structures called scrotum each testis is an oval white body aboutl l2 inches in length and covered with visceral peritoneum a Internally the testes is divided into compartments separated by gpta b Each compartment is filled with small coiled tubules called seminiferous tubules which produce sperm spermatozoa and have total length of about one half mile also male androgen production 1 Ducts that drain seminiferous tubules are the straight tubules rete testes efferent ducts to the epididymis 2 A mass of highly coiled ducts that collect sperm from the efferent ductules located somewhat like a cap on each testis is the epididymis and leading toward urethra is the w deferens c Interstitial cells of the testes produce androgenic hormone and are in uenced by the pituitam hormones d The testes are formed in the male fetus within the abdominal cavity near the level of the kidneys as the fetus matures the testes migrate downward and move through opening at base of abdominal cavity inguinal canal into scrotal sac this occurs shortly before birth if testes does not descend the condition is called cgptorchidism 3 From the vas deferens union with the duct from the seminal vesicle on the same side the ejaculatog duct is form ed the two ejaculatory ducts then enter the posterior surface of the prostate gland and continues through the substance of this gland for less than an inch before they end in the prostate portion of the urethra 4 Accessory structures those that secrete substances into the urethra comprises semen a Seminal vesicles located posterior to the urinary bladder and empty secretions into the ejaculatog duct this duct during sexual excitement ejects semen into urethra secretions 60 of semen volume produced by the vesicles contain simple sugars primarily fructose amino acids and mucus and is alkaline increases motility by reducing acidity in their environment spermatozoa do not enter the seminal vesicle b Prostate gm lies surrounding upper portion of urethra at base of the urinary bladder this structure secretes more uids slightly alkaline thereby aiding motility which combine with sperm as they are emptied into urethra the smooth muscle of this gland provides part of the force needed for ejaculation c Bulbourethral glands Cowper39s glands are two glands yellow in color and about the size of peas located further along the urethra distal to the prostate gland these glands secrete an alkaline mucus like substance that coats the lining of the urethra prior to ejaculation and lubricates end of penis in preparation for coitus d Penis male organ for copulation serves to introduce sperm into female vagina and also serves as part of the male urinary system the unstimulated penis is small and accid upon erotic stimulation it becomes firm enlarged and lengthened 1 It is composed of three cylindrical bodies which are located side by side in the dorsal half of the penis the cylinder lying beneath and between the upper two encloses the urethra these cylinders are made up internally of spongy tissue surrounded by tough fibrous tissue and are highly vascularized 2 During sexual excitement blood rapidly enters the corpora cavernosa and corpus spongiosum filling the spongy spaces leading to penis erection the ow of blood into the spaces creates a pressure upon the veins that drains the penis reducing or shutting off the outward ow of blood the penis remains erect until stimulation ceases causing arteries to constrict less blood then enters the cylinders and therefore less pressure is exerted on the veins allowing blood to leave the penis and permitting it to regain its unstimulated accid condition 3 At the distal of the penis the outer skin forms a fold or a cuff around the glans called the foreskin surgical removal of the foreskin is called circumcision 4 Semen spermatozoa plus secretions of the seminal vesicles prostate gland and the bulbourethral glands it is thick grayishwhite with average pH of 75 in average male each milliliter of semen contains about 100 million spermatozoa an average amount of ejaculate varies between 25 and 6mL semen is ejected by means of contraction of smooth muscle of prostate gland and contraction of the bulbocavernosus muscle which compresses the cavernous portion of the urethra sperm remain viable in the female tract from 48 to 72 hours ova viable for only 24 hours biol l207anatomy7reproductiveisystemdoc 22409 V Spermatogenesis Meiosis in the seminiferous tubules each diploid mother cell results in 4 haploid gametes or sperm atids that then undergo metamorphosis into spermatozoa with a distinct head body and tailflagellum begins in puberty and continues until death acceptable range for normal fertility 50 to 100 million with 60 motile males with less than 20 million are considered infertile spermatozoa are produced and matured at the rate of about 300 millionday location of the testes in the scrotum outside the abdominal cavity relates to the lower temperature requirement for sperm maturation a Spermiogenesis maturation of spermatids into 1 I 1 39 in the 39 39quot tubules they then pass to the epididym is where in 18 hours to 10 days maturity is reached acquires motility and the ability to fertilize an ovum sperm is stored in the vas deferens where they can retain viability up to several weeks H FEMALE REPRODUCTIVE SYSTEM A Anatomy 1 Female reproductive organs include paired ovaries paired uterine tubes F allopian uterus agina external genitalia and the mammag glands The ovaries are small almond shaped bodies about 112 inches in length that are located on either side of the uterus below the fallopian tubes weigh 6 grams approximately a Their major activities which occur simultaneously include the development and release of ova oogenesis and the production and release of fem ale horm ones progesterone and estrogen pituitag hormones also affect the ovaries They are attached medially to the uterus by the ovarian ligament lateral end is in intimate contact with free end of fallopian tube Structurally ovary consists of outer cortex and inner medulla free surface of cortex covered by single layer of cuboidal cells immediately below this is the connective tissue stroma of the cortex where the ovarian follicles are formed at time of birth each ovary contains about 250000 primav follicles of which each follicle is a mass of epithelial cells surrounding an immature ovum medulla is vascular loose connective tissue in which no follicles are found d Until puberty all ova are immature as oogenesis begins to resume with the menstrual cycle hormonal in uence will single out a single follicle of a single ovary to fully mature although several follicles are stimulated from both ovaries per cycle leads to the release of a single ovum ovulation approximately every 14th day of a female39s 28 day menstrual cycle The uterus is a hollow thickwalled muscular organ about 75 cm 3 long and 5 cm 2 wide at its widest point and tapering down to about 25cm It communicates cavity of uterus with fallopian tubes above and with vagina below It is flattened from front to back with the cavity slitlike Upper portion is the My with the lower constricted portion being called the cervix Upper portion is free and movable and rests on the upper surface of the urinary bladder position of uterus changes with size of the bladder Blood is supplied to uterus by way of branches of the internal lllj and ovarian arteries The inner lining is composed of special epithelial cells called the endometrium ST 0 E 995 run 1 It is composed of two chief layers a thick superficial or functional layer and a thin deep or basilar layer 2 Since the fem ale is not in a state of continual reproductive readiness the functional layer changes greatly during the menstrual cycle and is lost almost completely during menstruation under hormonal in uence Basilar layer is not lost and remains to regenerate a new functional layer when menstruation ceases lnitial functions are to retain and sustain the new individual during the first 40 weeks of growth gestation and development the final function is to expel the fetus and the placenta afterbirth at the end of pregnancy 4 The uterine tubes or fallopian m or oviducts and hollow extensions of the uterine cavity 4 12 inches long and functions to receive the ovulated secondary oocyte released from the ovary and by muscular contractions and the ciliated epithelium carry the ova in the direction of the uterus fertilization in distal third a Distally the free end has many fringelike projections or fimbriae that are in intimate contact with the ovary b The lining of the tubes is mucous membrane containing some ciliated cells and some secretory middle coat is composed of circular and longitudinal layers of smooth muscle that provide peristaltic contractions l The mucosa of the tube is continuous with that of the uterus and the vagina making possible the spread of harmful bacteria leading to infection biol l207anatomy7reproductiveisystemdoc 22409 BIOL l 120 REEDER PHYLUM ARTHROPODA quotJoint Footquot 1 Characteristics A 03 WUO T11 H W 3 b E BlOl l20PHYLUll ARTHROPODAREEDER Largest of all animal phyla and have attained greatest quotbiological success 1 34 of known animal species from this phyla approximately 800000 species 2 Occupy greatest variety of habitats air land fresh salt and brackish waters Consume the largest amounts and kinds of food 4 Capable of defending themselves against their enemies Phylogeny similarities between annelids and arthropods give strong support that both phyla originated from a line of coelom ate segmented ancestors annelid progenitor marine annelids and mollusks share comm on embryogenesis common of protostomes they share an outer cuticle and similar nerve system as well as similarities between lateral appendages of marine annelids and primitive arthropods most important is the segmented annelid plan and arthropod body structure Bilateral symmetry Usually externally segmented body of head thorax and abdomen distinct or fused internal to varying degrees tendency for somites to be fused into functional groups Appendages are jointed and highly modified for a large variety of functions 1 pair or none per somite joints allow exibility for movement or modified for specialized functions Distinguishing feature Rigid chitinous insoluble nitrogenous polysaccharide secreted by the epidermis bound by protein exoskeleton collectively called the cuticle Ca salts add to its hardness Distinguishing feature 1 Protects internal organs rigid armor and provides attachments for muscles 2 Prevents water loss as well as body uids in terrestrial species dehydration 3 Periodic Mnecessary for arthropod to increase size ec sis a Life cycle typically includes several molts 4 to 7x before adulthood and some continue after that b New covering grows causing old one to split open animal crawls out expands slightly then the new exoskeleton hardens salt reabsorption 4 Because of limiting weight and reduced exibility of exoskeleton no arthropod is of great size few exceed 60cm length largest is the Japanese crab 37m span with the smallest being the parasitic mite less than Complex muscle system with many and varied muscles composed of quickacting striated fibers smooth in visceral organs Complete digestive tract mouth parts with chewing jaws or else of sucking type anus terminally located Qpen circulatory system with reduced coelom dorsal contractile heart with arteries but with no veins hemocoel type of body cavity sinuses or spaces in the tissues filled with blood Respiration varies by gills tracheae air ducts book lungs parallel leaf like horizontal plates extending into a bloodfilled chamber in spiders or body surface Excretion by ggeen glands or by 2 to many Malpighian tubules on gut filters coelomic uid and excretes into the gut or coxal glands modified nephridia that open at the base of walking legs Nervous system of anterior quotbrainquot ganglia connected to paired ventral nerve cords and ganglia with nerves in each body somite or ganglia concentrated anteriorly annelid type sense organs as the eyes are usually large providing quick responses to stimuli senses include sight touch taste and smell Reproduction usually dioecious and unlike fertilization mostly internal eggs with yolk paired reproductive organs and ducts one or more larval or nymphal stages parthenogenesis unisexual reproduction involving the production of young by females not fertilized by males certain hormones stimulate embryogenesis common in rotifers aphids bees ants and wasps egg may be diploid or haploid l Metamomhosis implies changes in form involving a number of molts with each stage between successive molts called an instar a Complete separates the physiological processes of growth larva from those of differentiation pupa and reproduction adult each stage functions independently and efficiently without competition with other stages 88 of insects Gradual g Incomplete immature young are called nymphs wings develop externally in early instars and increase in size as animal grows by successive molts and becomes a winged adult many with aquatic larval stages grasshopper cicada mantids dragon ies may ies and stone ies Three 3 living subphyla l Chelicerata presence of chelicerae pincerlike fanglike or clawlike mouthparts with no antennae horseshoe crabs and arachnids 2 Crustacea have biramous appendages two jointed branches at their end two pairs of antennae and primarily mandibles shrimp crab lobster ST 2108 Page 1 of4 3 Uniramia mandibles with variations a single pair of antennae and unbranched appendages insects millipedes centipedes 0 Features for Arthropod Success 1 Versatile exoskeleton adapted for biting mouthparts sensory organs copulatory organs wings ornaments and armor attachment for muscle 2 Segmentation and appendages for more efficiency and better locomotion each somite has a pair of jointed appendages typically 3 Air piped directly to cells allows for a high metabolic rate tracheal system 4 Highly developed sense organs 5 Complex behavior patterns 6 Reduced competition through metamorphosis 7 Power of flight H Representative Classes B C BlOl l20PHYLUll ARTHROPODAREEDER Merostomata 1 Class includes many fossil forms and living species of horseshoe crabs Common to shallow marine waters off the Atlantic coast 3 chelicerae mouthparts 4 Characteristic dark brown outer covering carapace that is shaped like a horseshoe with a long tail spine telson posteriorly and 7 pairs of jointed appendages 5 prs of walking legs 5 Book gills flat leaf like on abdominal appendages 6 Harmless to humans Arachnida 1 Includes spiders mites ticks scorpions and harvest men daddy longlegs 2 Body of distinct cephalothorax and abdomen typically with 6 pairs of jointed appendages all in the cephalothorax fused head and thorax with no antennae 4 pair of walking legs chelicerae function as fangs or claws 3 Mouth parts and digestive tract mainly suited for sucking some with poison glands and claws fangs by which to stun or kill the insects and small animals used for food predaceous and feed largely on insects 4 Usually 8 single eyes chie y for perception of moving objects some may form images 5 Web spinning habit 2 or 3 pairs of spinnerets containing hundreds of microscopic tubes running to special abdominal silkglands proteinaceous material that hardens upon air exposure forms the silk thread threads function to trap food line nests form sperm web or egg sac warning safety line are stronger than steel threads of same diameter will stretch 15 of their length before breaking not all spiders spin webs for trapswolf jumping and fisher spiders chase and catch prey 6 Excretion utilizing Malpighian tubules significant to species living in a dry environment to conserve body fluids produces a quoturinequot containing salts and wastes rectal glands reabsorb most of the potassium and water leaving behind the chief waste uric acid that empties into the intestines and results in a m mixture of urine and feces may utilize coxal glands also modified nephridia that open at the base or coxa of the first and third leg 7 Chiefly terrestrial and solitary either freeliving and predaceous or parasitic 2 poisonous species in US black widow neurotoxin acts directly on the tissues of CNS and the brown recluse hemotoxin kills tissue surrounding the bite and breaks down the red blood cells Ticks are vectors of bacterial infections Rocky Mountain Spotted Fever and Lyme Disease lLites mange chiggers larvae of the red mite Malacostraca Crustaceans 1 Includes shrimp crabs lobsters crayfishes barnacles copepods water flea 2 Mostly marine with some freshwater forms as well as damp places on land 3 Most are freeliving and solitary some form schools while others are commensals or parasites 4 Range from filter feeder predators to scavengers 5 Compound eyes in most for detecting motion 6 Onlv class with 2 pairs of antennae mandibles and 5 pair of walking legs 7 Regeneration of lost parts chie y appendages and eyes also power of selfamputation 8 Crayfish example Cambarus freshwater form a Body of two main parts anterior rigid cephalothorax and jointed abdomen b Chitinous exoskeleton over the whole animal c Somites 5 of the head 8 of the thorax and 6 of the abdomen d Somites of the cephalothorax covered by a carapace continuous shield over dorsal and lateral surfaces with a cervical groove marking off the head and thorax laterally carapace covers the gills e Rostrum is an anterior pointed extension of the head with a stalked compound eye at each side 2108 Page 2 of4 f Mouth is ventrally surrounded by specialized mouth parts includes mandibles for biting and chewing and the M opens ventrally in the broad median telson at the abdomen39s end Appendages ventrally on each somite is a pair of jointed appendages 19 pairs First and second short antennules and long antennae for sensory Third to eighth mandibles maxillae 2 pair and maxillipeds 3 pair for cutting and handling food Ninth to thirteenth walking legs ninth is enlarged with heavy pincer cheliped for grasping food and defense39 tenth to thirteenth for locomotion food handling and body cleaning 4 Fourteenth to eighteenth abdominal swimmerets 5 pair for aid in respiration serve female to carry eggs fourteenth and fifteenth in male specialized for sperm transfer 5 Nineteenth broad uropods that with telson serve for backward swimming Digestive system 1 Mouth short esophagus two chambered stomach short midgut tubular intestine running dorsally in the abdomen to the anus 2 Two digestive glands liver lie under the stomach secretes digestive enzymes 3 Two part stomach contains calcified teLth forming a gastric mill to grind food Circulatory system open system hemocoel type cavity 1 M is middorsal in thorax its contraction pumps blood to body parts throuin arteries containing valves that prevent backflow blood escapes between organs collects in sinuses connecting to gills gas exchange then flows back to the heart via ostia no veins39 in a pericardial sac j Respiratory system 1 Laterally off thorax under the carapace are delicate plumelike g 2 Swimmerets keep water circulating over the gills 3 Blood pigment hemocyanin bluish pigment in the plasma aids oxygen transport Excretory system 1 Two large green glands in the head serve to remove wastes from the blood and bodily uids and excretes via ducts that open at the ventral bases of the antennae Nerve system and sense organs 1 quotBrainquot ganglia lies dorsal in the head with nerves serving the anterior sense organs and a pair of connectives around the esophagus leading to the double ventral w m the nerve cord also has ganglia that give off paired nerves to the appendages internal organs and muscles 2 Body has tactile hairs sensitive to touch 3 Antennules antennae and mouth parts that receive chemical stimuli taste and smell 4 Statocyst is a balance mechanism under base of each antennule 5 Compound eyes transmits images over optic nerve to the brain Reproductive system dioecious 1 Male has two soft white m fused beneath heart with slender coiled vas deferens on each side open at base of 5th walking leg 2 Female has two ovaries that resemble the testes in form and location39 eggs are discharged through an oviduct opening at base of third walking leg IQ mtg i VVV Fr W 3 D lnsecta 1 Estimated there may be as many as 5 million insect species of which fewer than a million have been identified and classified Are the most successful and abundant of all terrestrial animals first animal group to invade land Rank very high in organization of social groups which is necessary for species perpetuation honey bees ants termites utilize a caste system involving polymorphism along with differences in behavior and division of labor 4 Are the principal invertebrates that can live in dry environments and the only ones able to fly some can survive in temperatures as low as 30 F 35 C or as high as 120 F 49 C39 only few are marine brackish waters freshwater parasitic forms 9 5 Head thorax and abdomen distinct M with 1 pair of antennae and with 3 pairs of mouth parts modified variously for chewing sucking or lapping39 thorax of 3 somites with 3 pairs of jointed legs and usually 2 l or no pairs of wings abdomen of 11 or fewer somites with terminal parts modified as genitalia 6 Digestive tract of fore mid and hindgut39 mouth with salivary glands 7 Slender tubular heart situated dorsally with an anterior aorta to head no capillaries or veins body spaces a hemocoel 8 Respiration by branched cuticlelined tracheae ectodermal air tubes that carry oxygen from paired spiracles external openings of respiratory system on the thoracic and abdominal sides directly to the tissues some aquatic forms with tracheal or blood gills 9 Excretion by 2 to many fine Malpighian tubules lie in the hemocoel to remove nitrogenous wastes and salts from the blood and discharge with the feces attached to the anterior end of the hindgut BlOl l20PHYLUTVTARTHROPODAREEDER 2108 Page 3 of 4 BIOL l 120 REEDER The Angiosperms Division Anthophyta owering seed plants A racteristics 1 Contains six times the number of species of all other plant groups combined approximately 285000 species Earth39s dominant plants 2 Size varies from the small duckweed found on pond surfaces to shrubs vines herbs and treesize 3 Habitat greatly varies from deserts mountains polar regions marsh and estuaries to lakes and streams 4 Majority are autotrophic with exceptions Indian pipe plant that has little or no chlorophyll and is partially or wholly parasitic to the carnivorous but photosynthetic Venus flytrap pitcher plants sundews flytraps 5 Life cycle varies from a month to 20 to 30 years to reach sexual maturity some live for only a single growing season annuals other are perennia s 6 Crucial to the existence and economy of humans food clothing lumber fuel beverages drugs and medicines digitalis and codeine a cereal crops such as rice wheat corn and barley b valuable lumber such as oak cherry and walnut c fibers like cotton and linen d other products such as rubber tobacco coffee chocolate and aromatic oils for perfumes 7 Most distinctive feature of its member are the flowers sexual reproductive organ Evolution 1 Not linked clearly to any other group 2 Sprung up only once and suddenly and radiated rapidly into a variety of different forms a Structural and molecular data possibly indicates the gnetophytes of the gymnosperms as the closest living relatives 3 Found abundant in the fossil record of the Cretaceous period 70 million years ago when the earth was drying and cooling dinosaurs and most cycads were extinct and mammals and angiosperms were beginning domination 4 Great evolutionary success more efficient vascular tissue and extensive root system leaves with large surface area for photosynthesis seedlings can survive with less light than gymnosperms speed in growth and reproduction 1 presence of closed carpels results in fruit surrounding seeds double fertilization and faster seed production increases reproductive success relationships with various animals for pollination and seed dispersal due to flower attraction l helps to ensure crossfertilization dominant sporophyte GAMETIC overall adaptability to new habitats and changing environments rur iu pcrru Tquot I I J l Abundance and prominence of xylem vessel elements and phloem sieve tube members most gymnosperms have only tracheids smaller and acutely slanted at their cell wall endings comprising their xylem39 less efficient and specialized sieve cells comprise gymnosperm phloem 2 Formation of flowers and fruits most species are monoecious male and female parts on same ower with some dioecious species Presence of sepals petals or both in angiosperms 4 Formation of a pistil through which the pollen tube grows to reach the ovule and egg39 in gymnosperms the pollen lands on the ovule surface and the pollen tube must grow in directly39 ovules develop into seeds while the ovary wall develops into the fruit in angiosperms 5 Endosperm is triploid rather than haploid as in gymnosperms triploid is formed as a result of double fertilization instead of prior to fertilization as in gymnosperms Angiosperm classes 1 Dicotyledons most vegetables fruit and nut crops and angiospermous lumber trees deciduous a Families include buttercup Ranunculus mustard rose maplecactus carnation mint pea an parsle 1 Rose family includes apple pear plum cherry apricot peach almond and strawberry 9 ST F quot3 1 1 E BIOL l 120 REEDER SEXUAL REPRODUCTION IN FLOWERING PLANTS GAMETIC LIFE CYCLE I Sporulation Production of the spores and eventual gam etophytes A Production of microspores to pollen grains and steps to maturity 1 While the anther is growing inside a ower bud Mitosis produces four masses of diploid cells called mother cells within the microsporangium b Meiosis in each mother cell gives rise to four haploid microspores Each microspore will develop into an immature male gametophyte each microspore in a pollen sac mitotically divides forming two identical haploid nuclei tube cell nucleus and the forefather sperm cell that will later mitotically divide to form 2 sperm nuclei that stay together as a pollen grain enclosed in a protective wall may remain viable for millions of years and is resistant to desiccation d Once encased in the wall the anther splits freeing the pollen The gametophyte either reaches maturity before pollination or as the pollen tube grows to the micropyle of the ovule in the female gametophyte discussed shortly a C e 1 2 Once the pollen reaches the stigma the pollen grain becomes active growing as the pollen tube and digests its way through the stigma down the style to reach the ovule of the ovary a One of the haploid nuclei grows forming the pollen tube b The other haploid nuclei mitotically divides forming two sperm cells before or during tube growth c The germinated pollen grain with its tube nucleus and two sperm comprise the mature male gametophyte Female gametophyte has also achieved maturity embryo sac consists of seven cells B Production of megaspores to eggs and steps to maturity 1 At the same time in the carpels of the ower Ovule formation has begun through the mitotic formation of one or more domeshaped cell masses on the ovary39s inner wall a b gt lt gt lt 1 Each ovule is destined to become a seed In each ovule mass a diploid mother cell meiotically gives rise to four haploid megaspores within the megasporangium l 2 3 4 5 This area is covered with protective layers called integuments except for a tiny gap the micropyle which will be where a pollen tube will eventually penetrate into the ovu e In most owering plants three of the four megaspores disintegrate The fourth nearest the micropyle survives and undergoes 3 mitotic divisions without c oplasmic division39 initially results in a single cell with eight nuclei Each nucleus migrates to a specific location in the cell then cytoplasmic division occurs Results in the mature female gametophyte or embmo w consisting of seven cells Three cells near the micropyle in which one is the egg Three cells at the opposite end The one cell in the center contains two haploid nuclei central nucleus called the quotendosperm mother cell which will eventually give rise to the nutritive tissue endosperm that will surround the forthcoming embryo when fertilization occurs 833 Pollination transfer of pollen grains to the surface of a stigma A Types 1 Self pollination as in peas pollen simply falls from the anther to the stigma of the same ower Selfpollination is sometimes advantageous when external pollinators are scarce when plants are widely scattered or when crosspollination has not occurred at the end of a ower s life span a is common among annual plants often produce an abundance of seed to ensure species survival 2 Cross pollination Pollen from another plant of the same species tends to result in a species that is sturdier and more adaptable to environmental chan es Many plants have developed mechanisms that prevent selfpollination a biol l207sexualpreproductionp owering doc 1 2 V L V Some species produce only male stam inate owers on some plants and only fem ale pistillate owers on other plants Species with staminate and pistillate owers on the same plant and those with owers having both stamens and pistils often avoid selfpollination by shedding their pollen either before or after the stigmas on the same plant are receptive to it Chemical selfincompatibility the pollen either fails to grow on a stigma of the same plant or fails to produce pollen tubes that reach the ovules 42109 B The Process 1 Relies on wind or animals a Animal pollination is advantageous over the wind insects beetles bees ies butter ies moths wasps and larger animals birds bats snails rodents l The most important insect pollinators are bees which live on nectar and feed their larvae pollen and honey a bees have long tongues that can reach the nectar39 hairy bodies that pick up sticky pollen grains facilitating their transport to another ower39 and a sensitivity to colors and aromas that helps guide them to nectarproducing owers 2 Birds are important pollinators especially in tropical regions a many species have adapted to feeding on nectar pollen or owerinhabiting insects or spiders by developing slender beaks and brushlike or tubelike tongues b Animal may visit only one kind of plant many owers evolved structures so that only one species of animal can pollinate them39 yucca and moth species c Wind pollination although prevalent in the conifers and cycads is less comm on in angiosperms 1 plants using wind pollination produce large quantities of light powdery pollen that can be blown a considerable distance 2 to facilitate exposure to the wind the owers often bloom before the leaves come out in the spring or they may grow high upon the tree or plant 3 stigmas tend to be long and lobed to provide a large area for catching pollen 4 plants of one species frequently grow in dense populations 5 wind owers are usually inconspicuous and devoid of fragrance colors and nectar III F quot39 39 Embryonic and Fruit T Seed Germination Fruit Categories A Time Involved 1 May take place in as little as an hour after pollination or in several months B Double Fertilization l BLth sperm nuclei participate once the pollen tube reaches the micropyle a One fertilizes the egg nucleus to produce the diploid ygote b The other fertilizes the quotendosperm mother cell diploid forming the triploid endosperm 2 Immediately following fertilization the zygote enters period of dormancy a Endosperm nucleus becomes active dividing many times forming endosperm tissue enlarging and absorbing food from the sporophyte parent 3 The zygote breaks dormancy leading to embryonic development a Embryonic seed development in a dicot monocot embryonic development is identical in the early stages 1 The two cells formed as a result of the first division of the fertilized egg establishes polarity direction in the embr o 2 The bottom cell develops into a suspensor a multicellular anchor for the embryo and aids in nutrient uptake from the endosperm 3 The top cell develops into the actual embryo a Initially the top cell divides to form a short chain of cells proembryo b Cell division continues forming a small ball of cells globular embryo l Specialized tissues develop during this stage a Mitotic division of the zygote will form the radicle primary root the plumule shoot system and one or two cotyledons seed leaf used for nutrition in early growth as the seed germinates c As the two cotyledons begin to develop it has two lobes resembling a heart heartstage l monocots are more cylindrical due to a single cotyledon d In the tor39pedo stage the embryo enlarges and often curves back on itself crushing the suspensor be ond recognition 4 The wall of the ovule layer of the integument becomes larger and hardens to form the seed coat Outside the seed coat the ovary wall enlarges and absorbs nutrients to form the fruit ripened ovary begins to develop after pollination triggers hormonal changes that causes ovary to grow tremendously39 parallels development of the seed39 normally if ower has not been pollinated fruit does not set and ower withers and falls away a Fruit development pollen grain contains auxins amp gibberellins while further fruit growth depends on hormone production by the developing seed which in turn stimulates further hormone production auxins gibberellins cytokinins and ethylene in the young ovary wall The fruit is important to the plant from the standpoint of seed dissemination Not all fruits are eshy and delicious many are rather minimal layers pods of peas and beans V S7 o biol l207sexualpreproductionp owering doc 42109 P When the seeds are mature the fruit ruptures ripened and releases the seeds aids seed dispersal by attracting animals when ripe may remain bitter due to toxic chemicals so seeds won39t be removed too soon may have hooklike extensions to attach to anim al39 seed coat of seeds protect from digestion Classification of fruits 4 principal types 1 Simple derived from an ovary of a single pistil simple or compound one or more ovulebearing carpels may be eshy or dry at maturity cherry soybean pod pea peach tomato nuts grains and citrus fruits a Ovaries of eshy fruits often have three regions exoca139p mesocarp and endocar39p b In dry fruits the three layers characteristic of fleshy types are fused into one pericar39p which is often a thin layer around the see 2 Aggregate results from a single ower that has several simple pistils each with a separate carpel blackberry aggregate of tiny drupes raspberry and strawberry aggregateaccessory a after fertilization each ovary from each individual carpel enlarges resulting in the ovaries fusing to form a single fruit 3 Multiple develops from an in orescence a group of separate owers tightly clustered together when the walls of many ovaries start to thicken they fuse together becoming one fruit pineapple mulberry fig Osage orange bread fruit a pineapple aggregation of individual fruits each derived from a single ower spirally arranged around a eshy axis 4 Accessog fruits besides the ripened ovary wall or pericar39p other ower parts comprise the fruit sepals petals receptacle and stamens oral tube is fused with the ovary wall becoming eshy and ripening with it39 gourd family members such as the cucumber squash muskm elon cranberry gooseberry banana apple pear and strawberry a most accessory types are simple fruits that have developed from an inferior ovary39 the oral tube is fused with the ovary wall and becomes eshy and ripens with it b Pome fruits derived from a single ovary with a pericarp core differentiated into parts somewhat like a drupe39 apples and pears esh mostly of receptacle tissue oral tube 1 core of apples and pears begins the exocarp then meso then endocarp 2 outer eshy edible part is mostly receptacle c False berries the entire fruit ripens eshy as in true berries but are distinguished by the remnants of the ower that persist at the fruits top opposite the stem39 banana bears the scar of the fallen oral parts cranberry s apical end bears several small sepals Strawberry numerous simple pistils develop into tiny achenes seen outside the fruit and commonly called the seeds39 technically an aggregateaccessory 1 Each pistil contains a single ovule which develops into a seed within the achene 2 The edible accessory part of the fruit is the red eshy receptacle blackberries raspberries and strawberries besides aggregate accessory also elongated receptacle is eshy f Simple Fruit example t es 1 Simple Dy Fruits fruit wall becoming papery leathery or woody at maturity39 ac are generally dehiscent splits open at maturity usually along seams or sutures with more than one seed dh are generally indehiscent do not split open at maturity and usually contain one seed fruit has 3 layers fused into a single pericar39p thin layer around the seed Follicle most primitive fruit type derived from a ower with a simple pistil or a ower containing a number of simple pistils opens along one side only as in milkweed peonies larkspurs and columbines b Legume derived from a simple pistil opening along two sides as in members of the pea family alfalfa pea bean peanut indehiscent and cashew F amp e V 3 c Capsule develops from a compound pistil opening in a variety of ways one of most common kinds of simple dry fruits characterizing a number of plant families iris poppy Brazil nuts with hard woody seed coat the castor bean and the horse chestnut d Achene hard fruit coat of a single seed attached to the pericarp only at its base39 do not open at maturity39 buttercup and buckwheat families sun ower strawberry quotseedsquot 39lettuce and dandelion are winge e Grain caryopsis seed coat of a single seed fused with the pericar39p mature ripened ovary wall39 do not open at maturity39 fruit of the grass family corn wheat rye oats barley Samara a winged fruit usually of one seed elm ash tree of heaven and maple in pairs g m large oneseeded fruit with a woody or hard stony wall pericarp at ripening hazelnut beech oak hickory pecan biol l207sexualpreproductionp owering doc 42109 BIOL ll20 REEDER PHYLUM CNlDARIA quotsea nettles with stinging cellsquot or Coelenterata quothollow gutquot I General Characteristics biol 120 Jyhylum icnidaria current A U003 Q mm HF H W Lowest animal phyla with cells definitely forming tissues 1 Diploblastic a Thin external epidermis ectoderm b Thicker internal gastrodermis endoderm for digestive functioning c Thin noncellular layer mesoglea is found between the two Individuals are either solita or colonial 10000 species All species are aguatic most are marine with a few freshwater Members may have w of two forms or exhibit polymorphism existence within a species of two or more distinct forms or individuals two forms only would be dimorphic as in the cnidarians l Polyp tubular body closed at one end usually attached to some object having a central mouth surrounded by soft tentacles at the other end asexual stage Medusa umbrella shaped jellylike due to thicker mesoglea free swimming margined with soft tentacles mouth on a central projection manubrium of the concave surface sexual stage 3 Both forms may appear in the life cycle of many species although one form exists predominantly throughout the organism s life cycle N Radial Symmetry referred to as the quotRadiate Animalsquot Digestive body cavity is saclike gastrovascular body cavity no anus Incomplete mouth opening used to ingest and expel substances innovation allows for extracellular digestion that is retained by all of the more advanced animal groups incomplete through complete within a gut cavity instead of within individual cells Skeleton absent in many limy in some calcareous external skeleton some muscle fibers in the epithelium for contractility No circulatory respiratory or excretory organs simple diffusion of gases Nerve system consists of a nerve net nerve cells and fibers coursing through the body wall and tentacles eyespots in some species this is the first and simplest neural mechanism in animals providing for coordination in body and tentacle movement landmark in the evolution of the nerve system as show evidence of synapses with epitheliomuscular cells contain contractile fibers Reproduction commonly by asexual budding in the sessile polyp stage diploid alternating with sexual reproduction involving haploid gametes in a free medusa stage diploid l w a true alternation of generations as in many plants diploid generation alternating with a haploid one instead in animals termed metagenic both are diploid stages 2 Dioecious or monoecious 3 Medusa stage involves a ciliated planula larva relates to phylogeny most widely accepted theory is that the planula larva was derived from a radially symmetrical ciliated protist Have specialized minute stinging cells called cnidoc es which contain stinging quotthread capsulesquot called nematocysts l Capsule is filled with uid containing a coiled tubular thread which can inject a paralyzing uid neurotoxin 2 Commonly found on the tentacles 3 Discharged in presence of substances diffusing from nearby small prey animals and not necessarily by contact l1604 BIOL 1120 REEDER THE BRYOPHYTES I Nonvascular plants Sporic Life Cycle A Phylum Hepaticophyta the liverworts simpler than the mosses 1 Structure a Gametophyte maybe at sometimes branched ribbonlike structures that lie on the ground attached to soil by numerous rhizoids on the thallus underside and lacking a stem 1 Flattened lobed lea ike body form is called a thallus 2 Lobes of their thalli super cially resemble human liver lobes b Most species grow upright with a lea ike gametophyte the leafy liverworts have gametophytes with structures equivalent to stems branches and leaves but lack vascular tissues nottr stems roots nor leaves c The leafy liverworts are epiph ic nonparasitic plants that grow on other plants using the host for support on trees in tropical rain forests d The recognizable plant is the gametophyte generation e As in mosses the sporophyte grows as a parasite on the gametophyte f Are largely restricted to damp environments and are inconspicuous 2 Reproduction a Sporic type life cycle true alternation of generations 1 Archegonia and antheridia are produced on the haploid gametophyte b Asexual Gemma cups containing small ovoid gemmae can be found on the upper surface of some liverwort gametophytes gemmae may separate and grow into new gametophytes 3 Asexual reproduction can also occur by thallus branching and growth the individual thallus lobes elongate and becomes a separate plant when the older thallus dies B Phylum Bryophyta the mosses 1 Structure a Begins as a filamentous green thread the protonema that grows from a spore b From the protonema grows an erect green stemlike organ to which are attached a spiral whorl of leaflike structures haploid gametoph e generation no true stems nor leaves lacks vascular tissue c From the base of the stem extend many colorless hairlike rootlets called rhizoids not true roots d Size of mosses limited to a height of 15 to 20 cm due to the absence oftrue vascular and supporting tissues and the inefficiency of rhizoids as water absorbers 2 Reproduction a Sex organs develop at the top of the gametophyte stem in the middle of the leaf whorl b Some species are dioecious separate sexes while others are monoecious individual containing sex organs of both sexes c Sperm produced in the antheridium sausageshaped are spirally coiled and swim utilizing two agella d A rain or heavy dew triggers the sperm release and allows for a medium on the plant by which the sperm may swim to the female sex organ the archegonium askshaped containing one large egg either on the same plant or on another one archegonium releases a chemical to attract the sperm bi011207bryophytes 31704 BIOL l 120 l REEDER STEMS AND PLANT TRANSPORT Stems A Stem Functions 1 Support leaves and reproductive structures owers and fruits 2 Provides internal transport water and dissolved minerals from the roots to the leaves conduct sugar produced in leaves to roots and other parts lenticels will function for gas exchange on woody stems 3 Produces new living tissue throughout a plant39s life produces buds that develop into stems with new leaves andor reproductive structures B External Structure of a Woody Twig 1 All stems have M undeveloped embryonic shoots containing dormant apical meristems 2 Terminal bud embryonic shoot located at the stems tip a When dormant unopened and not actively growing it is covered and protected by outer bud scales modified leaves b When it resumes growth the bud scales fall off leaving budscale scars 1 These scars may persist for a number of years until they are finally obscured by the branch39s secondary rowt c The distance between any two sets of budscale scars marks the growth in length that twig made in a season therefore the age of a small branch may be determined by counting the scars from the terminal bud down the branch 3 Lateral buds located in the leaf axils upper angle between a leaf and the stem to which it is attached 4 Both terminal and lateral buds can form stems that bear leaves andor flowers when they grow Normally most of a plant39s axillary buds are repressed by hormones from the primary stem39s apical meristem called apical dominance of the terminal bud initially has produced the new stem tissues and leaf primordia of the main axis of the main shoot Most buds develop into leafy twigs and may be termed leaf buds Others called mixed buds contain the rudiments of leafy twigs and embryonic flowers apple and lilac Flower buds hold embryonic flowers only as in the peach cherry red maple and elm Flower and mixed buds may be terminal or axillary in position 5 A leaf scar shows where each leaf was attached previous to abscission a A layer of corky material seals the scar b Small pattern of corky dots may be seen as the bundle w remaining from strands of conducting vascular tissue that linked the stem with those of the leaf c Lateral buds are found above the leaf scars 6 Lenticels can be found as tiny marks or specks on the bark of a woody twig loosely arranged cells that allow for gas exchange 37 nap057 Stem Primary and Secondary Growth 1 Apical meristems are responsible for primary growth plant length and are located at the tips of roots and stems a As length growth occurs apical meristem leave behind leaf prim ordia and lateral M b The new tissues formed from apical meristems are called primag tissues 2 Lateral meristems are located along the stem and root sides and are responsible for increases in width a The new tissues formed from lateral meristems are called secondary tissues 3 All plants have primary growth but vary with secondary growth a Herbaceous plants typically have primary growth only b Woody plants have both primary and secondary growth 1 Increases in length occurs at the tips of its stems and roots while its older stems and roots further back from the tips increase in width 2 Secondary growth adds wood and bark causing the stem to thicken while at the same time primary growth stem length increases continues D Distinguishing Herbaceous Dicot and Monocot Stems Herbaceous dicot such as the sunflower a Outer covering of epidermis with cuticle b Several layer of cells called the cortex may contain 1 1 Functions may include photosynthesis storage and support c the vascular tissues are arranged as vascular bundles in a circle in cross section 1 n 1 1 1 and biol l207stemsampplantptransportdoc 4209 l Lengthwise the vascular bundles extend as long strands throughout the stem39s length and are continuous with the vascular tissues of both leaves and roots 2 Each vascular bundle a Xylem is located toward a stem39s interior and phloem is toward the exterior b Sandwiched between the two vascular tissues is a single cell layer called the vascular cambium lateral meristem responsible for secondary growth c Fibers and fiber clusters are found more extensively in phloem to help strengthen the stem d No clear separation of cortex and pith between the vascular bund es 2 Herbaceous monocots such as com a Outer covering of epidermis with cuticle b Vascular tissues run in strands lengthwise c In cross section the vascular bundles are scattered throughout the stem 1 Xylem arranged toward bundles inside and phloem toward the outside 2 Each bundle is enclosed in a sheath of sclerenchyma d No distinct areas of cortex or pith e Lateral meristems vascular cambium or cork cambium do not occur 1 No secondary growth wood or bark 2 Palm trees a monocot attain considerable size due to modified primary growth 3 Stems of bamboo and palm are extremely hard due to excessive sclerenchyma E Secondary Growth of Woody Dicots Angiosperms apple hickory maple and Gymnosperms pine spruce l Occurs as a result of two lateral meristems vascular cambium and cork cambium 2 Vascular cambium a Produces secondary tissues secondary xylem wood to replace primary xylem and secondary phloem inner bark to replace primary phloem ONLY a single layer of functional secondary phloem is maintained per year 1 Primary vascular tissues must be replaced in order for the plant to have an extended life span 3 Cork cambium a Produces cork cells and cork parenchyma 1 These tissues are collectively called the periderm outer bark 2 Functions to replace the epidermis 4 Secondary growth a Although vascular cambium is not initially a solid cylinder of cells it becomes continuous when secondary tissue production begins 1 Certain parenchyma cells in each pith ray retain division capability and form a complete ring of vascular cambium b As vascular cambium cells divide radially inward or outward one of the resulting cells remains meristematic as part of the vascular cambium while the other cells continue dividing several times until they stop mature and form secondary tissue c Vascular cambium produces tissue in two directions 1 Inside the ring forms secondary xylem or wood 2 Outside the ring forms secondary phloem or inner bark d As the stem increases in circumference vascular cambium cells also produce daughter cells that remain meristematic maintains the continuous ring of vascular cambium e Vascular cambium produces new wood on the inside of the ring allowing the plant to grow in diameter 1 Vascular cambium continues to divide and add more cells to the ring which continues to surround the most recently formed ring of secondary xylem completely as successive seasons pass f Cells produced outside the vascular cambium becomes secondag phloem which carries on food transport in place of the primary phloem which may be destroyed stretched and crushed by expansion of the inner part of the plant g As more secondary xylem forms the existing secondary phloem is destroyed in its turn and more secondary phloem is added to the outside of the vascular cambium functional secondary phloem remains about the same thickness The phloem that dies is incorporated into the so that the bulk of the stem comes to be made of xylem 1 As the secondary xylem and phloem are added by vascular cambium increasing the stem39s diameter the cortex and epidermis originally lying outside the vascular tissues are also stretched and destroyed39 fortunately a new outer protective layer of secondary tissue will form periderm 39 Fr biol l207stemsampplantytransportdoc 4209 r V Parenchyma cells in the epidermis or cortex form another lateral meristem the cork cambium the cork cambium produces new cells to the outside that eventually form the waterproofing layer suberin when they die39 called the periderm or outer on the tree39s outside Lenticels replace stem stomata as secondary growth occurs to facilitate gas exchange loosely arranged cork cells with many intercellular spaces j In cross section of a stem with welldeveloped secondary growth starting from the center and working outward pith primary xylem secondary xylem vascular cambium functional secondary phloem the crushed remains of the old primary and secondary phloem and cortex cork cambium and cork 1 When you peel M from a tree it breaks at the layer of delicate undifferentiated cells in the vascular cambium region the bark consists of functional secondary phloem crushed remains of old primary and secondary phloem and cortex cork cambium and cork 2 The trunk of the tree is almost entirely secondary xylem and very slender column of pith and primary xylem in the center 3 Phloem remains much the same thickness because old phloem dies and is incorporated into the bark 4 The oldest xylem located near the stem39s center becomes heartwood39 its cells become impregnated with resins and other strengthening substances skeletal function and are incapable of transporting root sap39 the best cabinet and construction wood is heartwood39 typically brownishred in color 5 The younger xylem located just inside of the vascular cambium is sapwood which is usually lighter in color annual rings of last several years conducts sap k In areas with pronounced growing seasons temperate desert climates some tropical humid areas there can be found differences in the amount of xylem produced from season to season In temperate zone trees within each secondary xylem layer there is often a big difference in color and texture between less compact thinwalled large diameter vessels springwood and the finerpored thicker walled small diameter vessels summer wood Springwood is the inner part of the ring lighter in color where more growth occurs due to greater moisture and higher concentrations of growth hormone auxin Summer wood is outer ring part that is darker because it is drier with less auxin produced39 both types of wood comprise an annual ring These differences result in the growth rings of woody dicots and gymnosperms that are used in dating 39 finds and 39 39 the clraracwri tic climate of past times 1 Primary tissues pith and primary xylem remaining inside the secondary xylem gets crushed due to secondary growth as time goes by39 primary tissues primary phloem cortex and epidermis located outside the vascular cambium are also split and sloughed off due to secondary growth 5 Hardwood vs Softwood a Hardwood harder wood of flowering plants due to the presence of fibers and vessel elements b Softwood softer wood of conifers conebearing gymnosperms due to the absence of fibers and vessel elements 2 V r V 2 V F Vascular Transport in Plants Xylem and Phloem 1 Water and dissolved minerals enter the roots from the soil 2 Once in the roots these substances are transported in the xylem to stems leaves and other structures 3 Sugar molecules manufactured by the leaf photosynthesis are transported in solution as the disaccharide sucrose throughout the plant body 4 Xylem transport is one direction only upward where as phloem transport translocation may occur upward or downward39 movement in both categories is due to natural physical processes Xylem Transport a Tracheids and vessel elements are the transporting cell types die at maturity b Physiology 1 Physical nature of water main constituent of sap physical processes living processes a Processes involved 1 Osmosis physical process involving the diffusion of water from an area of more water less solute to an area of less water higher solute concentration the higher solute concentration exerts a pulling force osmotic pressure on water in an attempt to equalize a Turgor pressure in plants the internal pressure generated by the incoming movement of water into the cell39s large central vacuole b Water potential energy of water a measure of the cell39s ability to absorb water by osmosis as well as a measure of water39s tendency to evaporate from cel s l The water potential of pure water is set at 0 mega pascals 2 When solutes are dissolved in water the free energy of water decreases a Water potential is lowered to a negative number V biol l207stemsampplant7transportdoc 4209 b Water moves from a region of higher less negative water potential to a region of lower m ore negative water potentia 3 Soil s water potential varies depending on how much water it contains a Extremely dry soil has a very low water potential while moister soil will have a higher water potential although still negative 4 Roots contain more dissolved minerals sugars and solutes than does soil water due to its ability to increase solute concentration via active transport roots have a more negative water potential than the soil so water moves by osmosis from the soil into the root 2 Active Transport living process requiring energy ATP and carrier systems to pump various solutes salts sugars ions as Na and TC from area of lesser concentration of solutes to an area of greater concentration 3 Evaporation conversion of liquid water to its gaseous state vapor transpiration from the leafs surface 4 Cohesion water being a polar molecule CHZO39 has a tendency to attract other water molecules which causes it to stick together and flow 5 Adhesion water molecules will be attracted to other polar substances as within the cell walls of the transporting xylem cell types c Transport mechanisms CohesionTension Theom l Capillarity cohesive and adhesive characteristics cause water to move into the small spaces of the xylem cells lined with polar substances even against the pull of gravity a Within tracheids and vessels water in the tubes center is pulled upwards as it is attracted to other water molecules and polar substances on the wall39s sides b The smaller the tube39s diameter the higher water will rise c Can reach a maximum height of 5 feet but is not enough for the rise of sap in many plants acting alone 2 Root Pressure pushing pressure from below is also required by sap to move upward39 not found in gymnosperms a Root absorption depends on active transport the root39s center accumulates ions from the soil resulting in lowering the water potential creates a hypertonic or concentrated solution of sap in the xylem b Water follows the concentration building hydrostatic pressure which pushes sap upward nowhere else for it to go with the Casparian strip preventing outward movement c The Casparian Strip of the endodermal root layer surrounds the central vascular tissue prevents sap from owing back out of the root to the soil d Adequate oxygen is needed to drive the aerobic production of ATP required for active transport e Root pressure alone cannot do the job39 root pressure can push sap only a few feet 3 Transpiration Pull pulling force on sap from above generated by the normal evaporation of water from the leaves driven by solar energy a Depends on the leaves being dry and exposed to air b The evaporation of water lowers the water potential more negative39 below 0 which increases the leafs osmotic pressure hypertonicity resulting in pulling more water upward c Cohesion and adhesion assist the process to replace water being pulled trough the entire water column of the xylem pipeline all the way down to the roots d The leaves are significant to the evaporative process involving their structural features as the cuticle stomata and guard cells their surface area is also significant Opposing this pulling movement on the sap is the frictional resistance from the xylem walls that at least doubles the pulling force required to raise the sap f Water intake is seventeen times that of a human39 necessary due to the fact that the plant transpires so much water to the atmosphere Structural features of the plant density and distribution of stom ata cuticle thickness and environmental factors availability of soil water sunlight intensity temperature affect the transpiration rate 6 Phloem Transport TRANSLOCATION a Sieve tube Members are the principal transporting cell types of angiosperms at maturity they are still considered living due to the presence of cytoplasm39 sieve cells in gymnosperms b The sugar sucrose is the predominant photosynthetic product carried c Phloem translocation is not as swift as xylem transport d Movement is both upward and downward 12 V ID V biol l207stemsampplantptransportdoc 4209 BIOL 1120 REEDER PLANT NUTRITIONAL REQUIREMENTS I Plant Requirements A Nutrients l Macronutrients 10 a Those required in large amounts carbon hydrogen oxygen nitrogen phosphorus potassium sulfur calcium magnesium and silicon b Used in quantities of up to one hundred to two hundred pounds per acre c Sources 1 CHO come from water amp gases 2 N from soil as ions of nitrogen salts nitrate NO339 amp ammonium NH439 3 Commercial fertilizers rated by percentage of those needed in greatest quantities EEK 5105 5 N 10 P 5 K by weight 4 Remaining nutrients derived from the soil as dissolved mineral ions 2 Micronutrients 9 a Those required in smaller amounts iron boron manganese copper molybdenum chlorine zinc sodium and nickel b Derived from the soil as dissolved mineral ions 3 De ciencies a An inadequate supply of any one of these minerals may result in either general de ciency symptoms chlorosis that results in yellowing paleness amp poor growth to more speci c symptoms slow growth stunting small leaves meristem death 13 SLII 1 Minerals used by plants come ultimately from rock particles making up the soil 2 Factors that in uence the soil s nature nature of the rock from which soil was derived climate of the region with weathering factors characteristic life in and on the soil the soil s exposure slope amp human activities 3 Classi ed according to the rock particles average size comprising the soil solid inorganic portion a nest particles less than 0002mm diameter b larger 002 to 0002mm c Sand largest 2 to 002mm 4 The varying proportions of these particles determine the soil texture with the percentage of m representing the most important fraction determining the soil s character Sands b Loams typically 40 sand amp silt 20 clay represents the agriculturally important soils c Silts Q Clays at least 40 clay 5 The particle39s si greatly in uences the soil s capacity to hold soil water a Amount of runoff in ltration amp percolation into the soil can vary 1 Runoff never penetrates the soil amp may carry away valuable nutrients 2 Amount of in ltration and percolation affects water available to plant life Water that remains in the soil is held by l Capillary attraction resulting in capilla water water held between particles against the force of gravity Fquot biol l 20jlant7nutritionalireqdoc 4309 a It lls the smaller pore spaces of the soil and is present as l around the soil particles amp as wedgeshaped masses at the points of contact between the particles hydrophilic soil particles b Capillary water is that available to plant root systems 2 Imbibition colloidal systems clay amp organic matteraggregate tightly bind water into their structure and is dif cult to remove by plant root systems c Clay soils hold more water than sandy soils due to all three factors capillary water lms amp imbibition Clay soils have ner particles creates capillary attraction with more surface area to form extensive films also clay is a colloid and thus strongly imbibes water 2 Sandy soils therefore are well drained while clays are waterlogged 3 to 6 times more a Because of clay39s strong capillary attraction the plant s root system cannot remove the water from the particles plus the soil is poorly aerated 6 Pore Spaces between the soil particles amp colloids are also signi cant to the available air amp water makeup as determined by the particle39s size and arrangement a 3060 of soil volume is suf cient to allow for rainwater in ltration rapid drainage amp proper aeration required for adequate plant growth 7 Best soil for most plants m mixture of particle sizes a Contains enough ne particles clay to provide a large surface area for retaining water amp minerals but enough coarse particles to provide air spaces amp prevent waterlogging C Organic Matter 1 Comprised of detritus leaf litter etc remains of plants and animals excrement 2 Holds soil water by imbibition a swells during rain amp shrinks when drying out b swelling amp shrinking keeps soil loose for easier root growth 3 Insulates the top of soil amp decreases evaporative water loss 4 Serves as a nutrient reservoir that is released slowly 5 Decomposing organic matter is called humus D Living Organisms l Composed of microorganisms bacteria algae protozoans to larger forms fungi insects worms etc Decomposes organic to inorganic signi cant in providing chemical forms that plants can then utilize in their metabolism a Nitrogen cycle 1 Bacteria amp bluegreen bacteria Rhizobium Nostoc Anabaena quot xquot nitrogen Nitrogen Fixation converts atmospheric nitrogen N2 dissolved in soil water to ammonia NH3 and ammonium NH4 which are chief forms of N utilized by plants 2 Nitrifying bacteria can then use quot xedquot nitrogen to make nitrites N02 and nitrates NOg39 in the process of nitri cation nitrates can also be utilized by plants 3 Still other bacteria can decompose animal remains amp wastes to ammonia in the process of ammoni cation 3 Larger animals can by burrowing loosen the soil for better aeration plus add further nutrients to the soil via their excrements E Ox en 1 Well aerated soil is signi cant to root respiration a if soil spaces are lled with water plants will die of asphyxiation b oxygen is needed for the active transport process signi cant to mineral absorption and xylem amp phloem transport V N biol l 20jlant7nutritionalireqdoc 4309 BIOL 1120 REEDER Phylum Platyhelminthes I Characteristics Representatives are microscopically small or up to 7 meters in length believed to have a cnidarianlike ancestor free living and parasitic forms Parasitic forms ukes and tapeworms show specialization suckers or hooks for holding on to the host bodies are resistant to the host39s digestive enzymes cuticle complicated life cycles utilizing one or more intermediate hosts followed by a definitive host produce large numbers of eggs of unneeded structures sense organs digestive system in certain members twp057 B Dorsoventrally attened bodies comm only called atworms to be distinguished from the nematoda roundworms parasitic forms from both groups are called helminths helminthology C No true segmentation D Bilateral symmetm with cephalization E Acoelomate Ebod cavity F 3 germ layers tissuetriploblastic Ectoderm Endoderm Mesoderm mesenchyme G Epiderm is soft and ciliated g covered by cuticle thin noncellular external covering for protection with external suckers or hooks or both for host attachment H Welldeveloped digestive muscular nervous excretory and reproductive systems as compared to coelenterates due to well developed organs muscular pharynx eyespots simple brain complex reproductive organs protonephridia 1 Digestive if present a Incomplete mouth but no anus and usually much branched absent in tapeworms parasitic quotsacquot body plan gastrovascular cavity 2 Muscle contracting muscle fibers that produces changes in body shape and assist locomotion sheathlike layers arranged in circular longitudinal and oblique layers a Spaces between fibers and internal organs filled by soft mass of cells parenchyma acts as a hydrostatic skelton 3 Nerve contains pair of anterior quotgangliaquot primitive brain or a nerve ring and one to three pair of lengthwise nerve cords with transverse connectives ladderlike statocysts for equilibrium tactile cells and chemoreceptors 4 Excretory contains protonephridia ending in specialized collecting cells called ame cells with long waving cilia located between body cells pinocytosis into the ame bulb which then leads into a highly branched system of tubules a Waste materials and excess water pass into ame cells and are driven by cilia into excretory ducts leading to excretory pores on exterior surface 5 Reproductive a Sexes usually monoecious containing gonads testis and ovary with a duct system b Internal fertilization c Microscopic eggs d Development either direct or with one or more larval stages e Asexual in some forms I m skeletal circulatory or respiratory systems 1 Fluid in parenchyma around internal organs serves to distribute products of digestion and to carry oxygen gases diffuse across the moist epidermis of the body exterior acts as a hydrostatic skeleton II Representative classes A Turbellaria freeliving atworms planarians Dugesia 1 Common to cool clear slow streams or ponds of freshwater avoid light by clinging to under surfaces of stones or logs in the water marine species as well 2 Two dark eyespots found dorsally on anterior end ocelli 3 Entire ventral surface covered by cilia for locomotion glides over a slime track 4 Midventrally the mouth opening is in an extensible muscular phagnx 5 Great powers of regeneration asexual mostly hermaphroditic crossfertilize into a common genital pore 6 Protonephridia with ame cells Trematoda ukes which are external and internal parasites 1 Characteristic thick cuticle protection with cilia hooks and suckers BIOL 1 120 1 U0 7391 3 1 VW Z P Q REEDER PHYLUlVl ANN ELIDA SEGMENTED WORMS Characteristics A Organisms of this phylum are referred to as segmented worms to distinguish from nonsegmented atworms and roundworm s Phylogeny ciliated trochophore larvae represents link with mollusks to primitive atworm ancestor also segmentation and embryogenesis shared with arthropods Habitats of members are widespread marine or fresh watersor on the land twothirds of phyla are marine Members considered highly developed due to a more centralized nerve system and more complex circulatory system Many are freeliving others burrow or live in tubes some are comm ensal on other aquatic animals and a few are parasites of vertebrates Bilateral symmetry body long and segmented both internally and externally external segments called somites or metam eres with interior divided into a series of ringlike compartments by thin transverse partitions or gpta between the somites Triploblastic ectoderm mesoderm endoderm with true coelom spacious body cavity outside the gut with mesodermal lining coelom is uidfilled divided by septa poorly developed coelom in leech coelomic uid acts as quoth drostatic skeletonquot Appendages of minute chitinous rods or bristles setae on each segment lacking in some forms as leeches Polychaeta marine worms with tentacles on the head and setae on eshy lateral lobes parapodia setae prevent backward slipping Body covered by moist cuticle over a sensory glandular epithelium mucus secreting onecelled epidermal glands Body wall and digestive tract with layers of circular external and internal longitudinal muscles antagonistic in action 1 Opposing contraction of muscle groups longitudinal and circular over the uid filled body allow for many kinds of movement peristaltic for example which progresses down the body39s length 2 Contraction in different parts of digestive tract allow for grinding and movement of food Complete digestive system tubular extending throughout body from mouth to anal opening Closed circulatory system composed of longitudinal vessels with branches to each segment hearts in oligochaeta and absent in polychaeta and hirudinea blood plasma with hemoglobin or other respiratory pigments No RBC but amoebocytes present coelomic uid assists Respiration by skin or by gills in some tube dwellers 1 Blood carries oxygen and carbon dioxide to and from various tissues Excretory system typically a pair or nephridia per body segment 1 Coiled tubular excretory organ 2 A ciliated funnel draws in wastes from the coelom into the nephridium and eventually out the excretory pore 3 Similar construction to excretory components of higher animals Cephalization nervous system concentrated at the anterior end of the organism in the form of paired cerebral ganglia brain a midventral nerve cord arises from these ganglia and extends posteriorly the length of the body small amounts of ganglia with branches nerves pass to each segment from the cord touch taste and light perception cells E organs are also present eyes with lenses in some Hermaphroditic forms earthworm leeches and dioecious forms marine worms with larval stage trochophore type in polychaetes reproduction by budding in some species Development egg to adult basically direct with no successive larval stages 11 Representative classes A B101 120PHYLUllANNEL1DASEGMENTEDWORMS REEDER Oligochaeta earthworms Lumbricus terrestris 1 External Anatomy Segmented with 4 pair setae per segment except on the first and last movement Mouth on somite 1 behind the prostomium anus on last somite Ventral surface is lighter color than dorsal plus the presence of seminal grooves Glandular clitellum over somites 32 to 37 involved in reproduction Many small external openings 1 1 pair of nephridiopores lateroventrally per segment except 1 to 34 and the last 2 2 pairs of openings from seminal receptacles laterally in grooves between somites 9 to 10 to 11 3 2 openings from the oviducts ventrally on somite 14 4 2 openings from the sperm ducts on somite 15 vas deferens prominent f Cm pimmn 39 somites or 09057 123001 19 Internal a Body wall b Spacious coelom and peritoneum lines body cavity and covers all organs within it c Septa internally to provide segmentation d Straight digestive tract 1 Mm buccal cavity 2 Phagnx moistens and moves food through tract 3 Esophagus moves food39 surrounded by 3 pair of whitish seminal vesicles 4 p temporary storage of food 5 Gizzard thickwalled highly muscular with the aid of small soil particles taken in during feeding grinds up vegetative food 6 Intestine for digestion and absorption a Typhlosole infolding with bulges in the intestines dorsal side which provides additional surface area for the digestion and the absorption of food b Food is chie y leafy vegetation as well as organic material in the earth M passage to the exterior of solid wastes e Circulatory System closed 1 Major blood vessels run longitudinall a Dorsal vessel lies on top of digestive tract main pumping organ b Ventral vessel lies below the tract c These vessels constitute the major circulatory pumps Hearts 5 pairs of connected vessels around the esophagus a Contain valves and contractile tissue b Play minor role in circulation 3 Blood red because of the hemoglobin a Not contained in cells as in humans but is dissolved in the plasma does contain ameboid cells f Reproductive System Hermaphroditic but do not self fertilize 1 Pair of large trilobed seminal vesicles between segments 9 and 13 that contain the m 2 pair for sperm production 2 The vesicles connect with the vas deferens sperm duct which exits to outside in segment 15 prominent and easy to see 3 Four small white spherical bodies two on each side called seminal receptacles lie in the 9th and 10th segments receives sperm from partner during mating 4 Pair of ovaries too small to be seen lie in segment 13 with pair of oviducts opening into segment 13 by way of a ciliated egg funnel and an opening to outside through ventral surface of segment 14 5 Copulation mating two worms come together in opposite directions along their ventral sides and become temporarily joined by secretion of a quotslime tube clitellum sperm are transferred between the worms along seminal grooves on ventral surface and enter the seminal receptacles of the other worm as eggs leave the ovaries the clitellum secretes a tube of mucus that slides over the anterior segments and pick up eggs from oviducts in segment 14 and sperm from segments 9 and 1039 the mucus tube finally slips over the worms anterior end to form the egg cocoon from which the young eventually hatch Nervous system 1 Major component is the ventral nerve cord runs the length of the worm on the inner ventral surface 2 At anterior end the cord divides and passes around the front part of the pharynx where it enlarges to form two swellings ganglia or quotbrainquot in 3rd segment suprapharyngeal ganglion 3 Along length of cord lateral nerves supply the body wall muscles Excretory System 1 Every body segment except the first three or four and the last contains a pair of excretory organs called nephridia nephridium a Each organ opens into the coelomic cavity just anterior to segment in which it is located b Wastes from m the coelom and the blood are excreted out the body via a pair of pores in each segment nephridiopores 2 Salt and water balance is maintained B Polychaeta freeliving marine worms largest and most primitive class 1 Abundant in depths ranging from lowtide to 50 meters a few found in depths of more than 4500 meters 2 Important to the marine food chain eaten by hydroids flatworms starfish and fis 3 Poorly developed reproductive system no permanent sex organs 4 Distinct head bearing eyes and tentacles N V 1 Fr B101 120PHYLUIlANNEL1DASEGMENTEDWORMS REEDER 123001 BIOL l 120 REEDER CIRCULATION HUNIAN THE CARDIOVASCULAR SYSTEM I Closed Circulatory System walls of the heart and vessels are continuous for blood to ow A Components required Blood a uid connective tissue composed primarily of formed elements RBC WBC platelets suspended in plasma comprised of water with various solutes plasma proteins nutrients wastes transportation medium Heart muscular pump that generates pressure required for blood to ow 4chambered l 9 B lood Vessels tubes of varying diameter for the transport of blood and exchanges to and from cells arteries veins capillaries B Blood l Functions 19 BIOl l20CIRCULATION HUIVIANREEDER ST 0 903 qu Pick up metabolic wastes capillary exchange of gases nutrients Deliver vital substances wastes Regulation of body temperature water39s properties vasodilation and vasoconstriction Acidbase balance pH 735745 buffering mechanism due to plasma proteins and hemoglobin Immunity Regulation of extracellular uid volume concentration due to plasma proteins Hemostasis blood clotting lood volume and composition Average male adult 56 L39 average female adult 4555 L39 averages 78 body weight 1 Chief variable of sex difference is the female39s greater percentage of body fat and male39s skeletal muscle Other characteristics 1 Viscosity resistance to ow blood is 5 times thicker than water 2 Hematocrit percentage of RBC in a blood sample a Indicates blood viscosi 3 Its composition re ects status of bodily functions Two main parts 1 Plasma constitutes 5060 of total blood volume in the adult a Strawcolored liquid containing primarily water solvent with suspended and dissolved nutrients wastes salts gases and proteins b Excellent transportation medium because of water c Hundreds of different plasma proteins including album in the globulins and fibrinogen 1 Maintenance of the distribution of water between the blood and interstitial uid found in minute spaces between and around the cells albumins colloid osmotic pressure COP 2 Transporting various substances globulins 3 Immunity globulins antibodies 4 Clotting hemostasis fibrinogen 5 Buffering for pH balance 2 Formed elements a Red blood cells erythrocytes l Oval biconcave unnucleated when mature life span of 120 days having sufficient enzymes and proteins prior to loss of nucleus 5 million per ml3 of blood Originates in the red bone marrow old cells removed by phagocytes of the liver and spleen Functions a Main function is transporting oxygen to cells 1 Contains hemoglobin iron containing protein molecule gives oxygen affinity oxyhemoglobin bright red in color reduced hemoglobin bluish in color when observed through blood vessel walls when depleted of oxygen 2 Transports some of the waste carbon dioxide 23 as carbaminohemoglobin 3 Buffering the protein globin Feedback mechanisms regulate the red blood cell count approx 2 millionsec rate of production rate of destruction a Hypoxia low blood oxygen kidney39s low oxygen level results in an enzyme that converts a plasma protein into a hormone that eventually stimulates RBC production in the red bone AAA 4 L N VVV A Lquot V m arrow b White Blood Cells leukocytes 22409 1 Larger nucleated cells of which there are five types distinguished on the basis of size nuclear shape staining traits and the presence of granules in their cytoplasm lymphocytes TCells amp B cells neutrophils monocytes eosinophils and basophils 500010000 ml3 depending on whether the body is active in a healthy state or fighting infection Formed in red bone marrow and lymphatic tissue spleen thymus tonsils Functions include phagocytizing foreign materials producing antibodies against infectious agents and housekeeping chores remove dead or wornout ce s Release a number of chemicals Heparin anticlotting Histamine increase membrane permeability Serotonin vasoconstrictor Chemicals associated with allergic and in ammatory reactions 6 Two Categories ofWBC Granulocytes lobed nucleus with cytoplasmic granules l Neutrophils pinkish in neutral stain 2 Eosinophils red dye in acid stain 3 Basophils basic dye stains deep blue b Agranulocytes circular or indented nucleus no granules l Monocytes very large 2 Lymphocytes smaller 7 Most mobile and active phagocytes neutrophils PMN39s and monocytes macrophages c Platelets Thrombocytes 1 Are merely cell fragments bits of cytoplasm are pinched off large red bone marrow cells called megakaryocytes 2 200400 platelets per ml3 blood 3 Form temporary seals platelet plug in blood vessels and aid in blood clotting a Platelet contact with injured vessel wall causes platelets to swell become sticky and release certain chemicals some lead to vessel vasoconstriction39 others increase platelet plug activity39 some help initiate blood clotting process intrinsic pathway of hemostasis AAA 4 L N VVV A Lquot V AA A 90 9 A m V C The Heart Cardiac Muscle Involuntary striated appearance due to internal proteins with each m a separate cell with its own nucleus fused to others at junctions creating a branching network with the membranetomembrane junctions forming intercalated disks dark marks seen under the microscope representing muscle fiber junctions a Bulk of the human heart the myocardium is the thickest in the walls of the left ventricle and to a lesser degree in the right ventricle s walls r 2 Pericardium the heart39s outer protective covering is composed of fibrous connective tissue 3 The heart39s inner lining the endothelial layer that is continuous with that of its blood vessels is normally very sm ooth 4 The heart lies in the mediastinum of the thoracic cavity sitting ventral in the body 5 Vessels to and from the heart a Leading to the heart deoxygenated blood from the superior and inferior vena cavae from the body and the coronag sinus draining the coronary veins of the heart itself empty into the right atrium b Leaving the heart oxygenated blood from the left ventricle exits via the M to supply the body giving off coronag arteries immediately to supply the heart 6 Four heart chambers two upper chambers gm and E m or auricles and two lower chambers ght and ventricles a Valves of the heart 1 Right or tricuspid and left bicuspid atrioventricular valves separate the respective upper atrium from the lower ventricle of each side 2 Semilunar valves regulate flow from the respective ventricle to the chief artery a Pulm onag semilunar between the right ventricle and pulmonary artery b Aortic semilunar between the left ventricle and aorta 3 The valves open and close according to pressure changes on one side of the valve and the other 7 Heart operates like two pumps lying side by side Double Circulation a Right side right atrium and ventricle receives deoxygenated blood and pumps to Pulmonary Circulation b Left side left atrium and ventricle receives oxygenated blood from the pulmonary circuit and pumps to Systemic Circulation Modified cardiac muscle tissue in certain areas of the heart muscle are found modified and specialized heart muscle cells that form the excitatory and conductive system of the heart 00 BlOl lZOClRCULATlON HUTVTANREEDER 22409 a This feature allows the atria and the ventricles to alternately contract and relax in an orderly sequence due to the intrinsic beat of the heart operates within the heart and not requiring direct nerve supply autonomic system is used to increase or decrease the rate according to the demands of the bod l The heartbeat is normally regulated by a pacemaker called the sinoatrial or SA node The SA node is a small area of myocardial cells embedded in the dorsal part of the right atrial wall It initiates the wave of excitation that spreads quickly throughout the atria both right and left resulting in contraction while the ventricles are relaxing 2 The wave then makes contact with a second node the atrioventricular or AV node located at the base of the right atrium near the wall that separates the two atria The wave then spreads through the myocardium of the wall via the Bundle of His to branching fibers between the two ventricles to the purkinje fibers that spread into the muscle of the lateral ventricular walls This wave initiates ventricular contraction as the atria relax 9 Cardiac Cycle a Systole contraction and diastole relaxation make up one complete beat 08 sec blood volume and myocardial contraction significant in bringing about required pressure changes 1 While the atria are relaxed and filling the ventricles are also relaxed AV Valves are closed 2 Pressure rises in the atria AV valves open ventricles fill as atria begin to contract 3 Ventricles begin to contract semilunar valves are closed pressure causes the AV valves to close 4 Ventricular pressure continues to rise eventually above the pressure in the vessels leading out of them39 semilunar valves open and blood flows emptying both ventricles into their major artery 5 atrial systole 01 sec 08 6 atrial diastole 07 sec sec 7 ventricular systole 03 sec 08 8 ventricular diastole 05 sec sec 10 Heartbeat Sounds lubbdup a lubb contraction of ventricles and closure of the AV valves b dup closing of the semilunar valves llCardiac Output or minute volume CO a Stroke rate 7080 beatsmin females have higher rates SR b Stroke volume 6070 ml blood per beat39 SV c CO mlmin SR beatsmin x SV mlbeat d CO averages about 5 Lmin at rest39 can increase up to 15 to 20 L during exercise l2Blood Pressure pressure within the heart is determined by blood volume and myocardial contraction with arteriole vasoconstriction providing normal maintenance throughout the vascular bed of the body a With each heartbeat the blood is pushed onward exerting a force hydrostatic pressure against the walls of a vessel39 the pressure is highest nearest its source heart and gradually decreases as blood moves further away from its pumping source Difference in pressure required for blood to flow Pulse expansion of the arterial wall that passes down the arterial blood vessels following ventricular systole as blood courses through the vascular system39 one arterial pulse per ventricular systole39 the arterial pulse rate can be used to determine heart rate radial artery of the wrist brachial in the arm carotid in the neck temporal of the temple femoral in the thigh and the dorsalis pedis of the foot Two different pressure levels alternate in the large arteries 1 Systolic pressure blood forced into the arteries during ventricular systole 2 Diastolic pressure pressure in arteries during ventricular diastole elastic recoil of the arteries allows blood to flow into the capillary beds 3 12080 mm Hg39 instrument used sphygmomanometer Arteriole vasoconstriction and vasodilation assists in normal maintenance re ex control diameter of vessel offers varying degree of resistance to the flow of blood thus resulting in the heart working harder or less in order to generate sufficient pressure39 action of the autonomic nerve system D Blood Vessels Inner lining endothelium 1 Systemic Arteries thickwalled elastic and strong39 designed to carry blood under high pressure away from the heart39 elastic recoil of artery normally maintains blood flow between beats capillary flow a Lead to arterioles smaller in size decreased diameter contain sphincters that encircle the arterioles at the capillary bed entrance functioning to regulate flow and pressure39 vasoconstriction and vasodilation of the arterioles reflex controlled contraction and relaxing of smooth muscle in the arteriolar walls are significant in maintenance of arterial blood pressure 2 Capillaries thinwalled only one cell layer thick for optimum diffusion of substances to provide for material exchange gases nutrients wastes between the tissues and the blood39 considered the focal point of the circulatory system39 interstitial spaces immediately around cells 7 0 P BlOl l20ClRCU39LATlON HUTVTANREEDER 22409


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