BSC 116 Test number 2 study guide
BSC 116 Test number 2 study guide BSC 116
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This 24 page Study Guide was uploaded by Ashley Bartolomeo on Monday February 29, 2016. The Study Guide belongs to BSC 116 at University of Alabama - Tuscaloosa taught by Professor Harris in Spring 2016. Since its upload, it has received 183 views. For similar materials see Principles Biology II in Biological Sciences at University of Alabama - Tuscaloosa.
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Study Guide Test 2 Chapter 38 Vocabulary Accessory Fruit A fruit, or assemblage of fruits, in which the fleshy parts are derived largely or entirely from tissues other than the ovary Aggregate Fruit A fruit derived from a single flower that has more than one carpel Apomixis The ability of some plant species to reproduce asexually through seeds without fertilization by a male gamete Asexual Reproduction The generation of offspring from a single parent that occurs without the fusion of gametes (by budding, division of a single cell, or division of the entire organism into two or more parts). In most cases, the offspring are genetically identical to the parent Biofuel A fuel produced from biomass Biomass The total mass of organic matter comprising a group of organisms in a particular habitat Callus A mass of dividing, undifferentiated cells growing in culture Carpel The ovuleproducing reproductive organ of a flower, consisting of the stigma, style and ovary Coevolution The joint evolution of two interacting species, each in response to selection imposed by the other Coleoptile The covering of the young shoot of the embryo of a grass seed Coleorhiza The covering of the young root of the embryo of a grass seed Complete Flower A flower that has all four basic floral organs: sepals, petals, stamens and carpels Dioecious In plant biology, having the male and female reproductive parts on different individuals of the same species Double Fertilization A mechanism of fertilization in angiosperms in which two sperm cells unite with two cells in the female gametophyte (embryo sac) to form the zygote and endosperm Embryo Sac The female gametophyte of angiosperms, formed from the growth and division of the megaspore into a multicellular structure that typically has eight haploid nuclei Endosperm In angiosperms, a nutrientrich tissue formed by the union of a sperm with two polar nuclei during double fertilization. The endosperm provides nourishment to the developing embryo in angiosperm seeds Epicotyl In an angiosperm embryo, the embryonic axis above the point of attachment of the cotyledon(s) and below the first pair of miniature leaves Fragmentation A means of asexual reproduction whereby a single parent breaks into parts that regenerate into whole new individuals Fruit A mature ovary of a flower. The fruit protects dormant seeds and often functions in their dispersal Herbivory An interaction in which an organism eats part of a plant or alga Hypocotyl In an angiosperm embryo, the embryonic axis below the point of attachment of the cotyledon(s) and above the radicle Hypothalamus The ventral part of the vertebrate forebrain; functions in maintaining homeostasis, especially in coordination the endocrine and nervous systems; secretes hormones of the posterior pituitary and releasing factors that regulate the anterior pituitary Imbibition The physical adsorption of water onto the internal surfaces of structures Incomplete Flower A flower in which one or more of the four basic floral organs (sepals, petals, stamens or carpels) are either absent or nonfunctional Inflorescence A group of flowers tightly clustered together Megaspore A spore from a heterosporous plant species that develops into a female gametophyte Microspore A spore from a heterosporous plant species that develops into a male gametophyte Multiple Fruit A fruit derived from an entire inflorescence Ovary The portion of a carpel in which the egg containing ovules develop Ovule A structure that develops within the ovary of a seed plant and contains the female gametophyte Petal A modified leaf of a flowering plant. Petals are the often colorful parts of a flower that advertise it to insects and other pollinators Pistil A single carpel or a group of fused carpels Pollen Tube A tube that forms after germination of the pollen grain and that functions in the delivery of sperm to the ovule Pollination The transfer of pollen to the part of a seed plant containing the ovules, a process required for fertilization Radicle An embryonic root of a plant Receptacle The base of a flower; the part of the stem that is the site of attachment of the floral organs Seed Coat A tough outer covering of a seed, formed from the outer coat of an ovule. Seed coat enclosed and protects the embryo and endosperm SelfIncompatibility The ability of a seed plant to reject its own pollen and sometimes the pollen of closely related individuals Sepal A modified leaf in angiosperms that helps enclose and protect a flower bud before it opens Simple Fruit A fruit derived from a single carpel or several fused carpels Stamen The pollen producing reproductive organ of a flower, consisting of an anther and a filament Style The stalk of a flower’s carpel, with the ovary at the base and the stigma at the top Vegetative Propagation Asexual reproduction in plants that is facilitated or induced by humans Vegetative Reproduction asexual reproduction in plants Important Information Angiosperm reproduction involves an alternation of generations between a multicellular diploid sporophyte generation and a multicellular haploid gametophyte generation. Flowers, produced by the sporophyte, function in sexual reproduction The four floral organs are sepals, petals, stamens and carpels. Sepals protect the floral bud. Petals help attract pollinators. Stamens bear anthers in which haploid microspores develop into pollen grains containing a male gametophyte. Carpels contain ovules (immature seeds) in their swollen bases. Within the ovules, embryo sacs (female gametophytes) develop from megaspores Pollination, which precedes fertilization, is the placing of pollen on the stigma of a carpel. After pollination, the pollen tube discharges two sperm into the female gametophyte. Two sperm are needed for double fertilization, a process in which one sperm fertilizes the egg, forming a zygote and eventually an embryo, while the other sperm combines with the polar nuclei, giving rise to the foodstoring endosperm The seed coat encloses the embryo along with the food supply stocked in either the endosperm or the cotyledons. Seed dormancy ensures that seeds germinate only when conditions for seedling survival are optimal. The breaking of dormancy often requires environmental cues, such as temperature or lighting changes The fruit protects the enclosed seeds and aids in wind dispersal or in the attraction of seeddispersing animals Asexual reproduction, also known as vegetative reproduction, enables successful plants to proliferate quickly. Sexual reproduction generates most of the genetic variation that makes evolutionary adaptation possible Plants have evolved many mechanisms to avoid selffertilization, including having male and female flowers on different individuals, nonsynchronous production of male and female parts within a single flower, and selfincompatibility reactions in which pollen grains that bear an allele identical to one in the female are rejected Plants can be cloned from single cells, which can be genetically manipulated before being allowed to develop into a plant Hybridization of different varieties and even species of plants is common in nature and has been used by breeders, ancient and modern, to introduce new genes into crops. After two plants are successfully hybridized, plant breeders select those progeny that have the desired traits In genetic engineering, genes from unrelated organisms are incorporated into plants. Genetically modified (GM) plants can increase the quality and quantity of food worldwide and may also become increasingly important as biofuels Two important GM crops are Golden Rice, which provides more vitamin A, and Bt maize, which is insect resistant There are concerns about the unknown risks of releasing GM organisms into the environment, but the potential benefits of transgenic crops need to be considered Chapter 32 Vocabulary Acoelomate A solidbodied animal lacking a cavity between the gut and outer body wall Anterior Pertaining to the front, or head, of a bilaterally symmetrical animal Archenteron The endodermlined cavity, formed during gastrulation, that develops into the digestive tract of an animal Bilateral Symmetry Body symmetry in which a central longitudinal plane divided the body into two equal but opposite halves Bilaterian A member of a clade of animals with bilateral symmetry and three germ layers Blastopore In a gastrula, the opening of the archenteron that typically develops into the anus in deuterostomes and the mouth in protostomes Blastula A hollow ball of cells that marks the end of the cleavage stage during early embryonic development in animals Body Cavity A fluid or air filled space between the digestive tract and the body wall Body Plan In multicellular eukaryotes, a set of morphological and developmental traits that are integrated into a functional whole – the living organism Cambrian Explosion A relatively brief time in geologic history when many presentday phyla of animals first appeared in the fossil record. This burst of evolutionary change occurred about 535–525 million years ago and saw the emergence of the first large, hardbodied animals. Cleavage (1) The process of cytokinesis in animal cells, characterized by pinching of the plasma membrane. (2) The succession of rapid cell divisions without significant growth during early embryonic development that converts the zygote to a ball of cells Coelom A body cavity lined by tissue derived only from mesoderm Coelomate An animal that possesses a true coelom (a body cavity lined by tissue completely derived from mesoderm) Determinate Cleavage A type of embryonic development in protostomes that rigidly casts the developmental fate of each embryonic cell very early Deuterostome Development In animals, a developmental mode distinguished by the development of the anus from the blastopore; often also characterized by radial cleavage and by the body cavity forming as outpockets of mesodermal tissue Deuterostomia One of the three main lineages of bilaterian animals. Diploblastic Having two germ layers Dorsal Pertaining to the top of an animal with radial or bilateral symmetry Ecdysozoa One of the three main lineages of bilaterian animals; many ecdysozoans are molting animals Ectoderm The outermost of the three primary germ layers in animal embryos; gives rise to the outer covering and, in some phyla, the nervous system, inner ear and lens of the eye Edicaran Biota An early group of macroscopic, softbodied, multicellular eukaryotes known from fossils that range in age from 635 million to 535 million years old Endoderm The innermost of the three primary germ layers in animal embryos; lines the archenteron and gives rise to the liver, pancreas, lungs and the lining of the digestive tract in species that have these structures Eumetazoan A member of a clade of animals with true tissues. All animals except sponges and a few other groups are eumetazoans Gastrula An embryonic stage in animal development encompassing the formation of three layers: ectoderm, mesoderm and endoderm Gastrulation In animal development, a series of cell and tissue movement in which the blastula stage embryo folds inward, producing a three layered embryo, the gastrula Indeterminate Cleavage A type of embryonic development in deuterostomes in which each cell produced by early cleavage divisions retains the capacity to develop into a complete embryo Invertebrate An animal without a backbone. Invertebrates make up 95% of animal species Larva A freeliving, sexually immature form in some animal life cycles that may differ from the adult animal in morphology, nutrition and habitat Lophophore In some lophotrochozoan animals, including brachiopods, a crown of ciliated tentacles that surround the mouth and function in feeding Lophotrochozoa One of the three main lineages of bilaterian animals; lophotrochozoans include organisms that have lophophores or trochophore larvae Mesoderm The middle primary germ layer in a triploblastic animal embryo; develops into the notochord, the lining of the coelom, muscles, skeleton, gonads, kidneys and most of the circulatory system in species that have these structures Metamorphosis A developmental transformation that turns an animal larva into either an adult or an adult like stage that is not yet sexually mature Protostome Development In animals, a developmental mode distinguished by the development of the mouth from the blastopore; often also characterized by spiral cleavage and by the body cavity forming when solid masses of mesoderm split Pseudocoelomate An animal whore body cavity is lined by tissue derived from mesoderm and endoderm Radial Cleavage A type of embryonic development in deuterstomes in which the planes of cell division that transform the zygote into a ball of cells are either parallel or perpendicular to the vertical axis of the embryo, thereby aligning tiers of cells one above the other Radial Symmetry Symmetry in which the body is shaped like a pie or barrel (lacking a left side and a right side) and can be divided into mirrorimaged halves by any plane through its central axis Spiral Cleavage A type of embryonic development in protostomes in which the planes of cell division that transform the zygote into a ball of cells are diagonal to the vertical axis of the embryo. As a result, the cells of each tier sit in the grooves between cells of adjacent tiers Tissue An integrated group of cells with a common structure, function or both Triploblastic Possessing three germ layers: the endoderm, mesoderm and ectoderm. All bilaterian animals are triploblastic Trochophore Larva Distinctive larval stage observed in some lophotrochozoan animals, including some annelids and molluscs Ventral Pertaining to the underside or bottom of an animal with radial or bilateral symmetry Vertebrate A chordate animal with vertebrae, the series of bones that make up the backbone Important Facts Animals are heterotrophs that ingest their food Animals are multicellular eukaryotes. Their cells are supported and connected to one another by collagen and other structural proteins located outside the cell membrane. Nervous tissue and muscle tissue are key animal features In most animals, gastrulation follows the formation of the blastula and leads to the formation of embryonic tissue layers. Most animals have Hox genes that regulate the development of body form. Although Hox genes have been highly conserved over the course of evolution, they can produce a wide diversity of animal morphology Fossil biochemical evidence and molecular clock analyses indicate that animals arose over 700 million years ago Genomic analyses suggest that key steps in the origin of animals involved new ways of using proteins that we encoded by genes found in choanoflagellates Animals may lack symmetry or may have radial or bilateral symmetry. Bilaterally symmetrical animals have dorsal and ventral sides, as well as anterior and posterior ends Eumetazoan embryos may be diploblastic (two germ layers) or triploblastic (three germ layers). Triploblastic animals with a body cavity may have a pseudocoelom or a true coelom. Protostome and deuterstome development often differ in patterns of cleavage, coelom formation, and blastopore fate Chapter 33 Vocabulary Brachiopod A marine lophophorate with a shell divided into dorsal and ventral halves; also called lamp shells Alimentary Canal A complete digestive tract, consisting of a tube running between a mouth and an anus Ammonite A member of a group of shelled cephalopods that were important marine predators for hundreds of millions of years until their extinction at the end of the Cretaceous period (65.5 million years ago) Amoebocyte An amoebalike cell that moves by pseudopodia and is found in most animals. Depending on the species, it may digest and distribute food, dispose of wastes, form skeletal fibers, fight infections, or change into other cell types Arachnid A member of a subgroup of the major arthropod clade Chelicerata. Arachnids have six pairs of appendages, including four pairs of walking legs, and include spiders, scorpions, ticks and mites Arthropod A segmented ecdysozoan with a harrd exoskeleton and jointed appendages. Familiar examples include insects, spiders, millipedes and crabs Book Lungs An organ of gas exchange in spiders, consisting of stacked plates contained in an internal chamber Chelicera One of a pair of clawlike feeding appendages characteristic of chelicerates Choanocyte A flagellated feeding cell found in sponged. Also called a collar cell, it has a collarlike ring that traps food particles around the base of its flagellum Cnidocyte A specialized cell unique to the phylum Cnidaria; contains a capsulelike organelle housing a coiled thred that, when discharged, explodes outward and functions in prey capture or defense Complete Metamorphosis The transformation of a larva into an adult that looks very different, and often functions very differently in its environment, than the larva Echinoderm A slowmoving or sessile marine deuterstome with a water vascular system and, in larvae, bilateral symmetry. Echindoerms include sea stars, brittle stars, sea urchins, feather stars, and sea cucumbers Ectoproct A sessile, colonial lophophorate; also called a bryozoan Eurypterid An extinct carnivorous chelicerate; also called a water scorpion Exoskeleton A hard encasement on the surface of an animal, such as the shell of a mollusk or the cuticle of an arthropod, that provides protection and points of attachment for muscles Filter Feeder An animal that feeds by using a filtration mechanism to strain small organisms or food particles from its surroundings Foot One of the three main parts of a mollusk; a muscular structure usually used for movement Hermaphrodite An individual that functions as both male and female in sexual reproduction by producing both sperm and eggs Incomplete Metamorphosis A type of development in certain insects, such as grasshoppers, in which the young (called nymphs) resemble adults but are smaller and have different body proportions. The nymph goes through a series of molts, each time looking more like an adult, until it reaches full size Invertebrate An animal without a backbone. Invertebrates make up 95% of animal species Mantle One of the three main parts of a mollusk; a fold of tissue that drapes over the mollusk’s visceral mass and may secrete a shell Mantle Cavity A waterfilled chamber that houses the gills, anus and excretory pores of a mollusk Medusa The floating, flattened, mouthdown version of the cnidarian body plant. The alternate form is the polyp Mesohyl A gelatinous region between the two layers of cells of a sponge Molting A process in ecdysozoans in which the exoskeleton is shed at intervals, allowing growth by the production of a large exoskeleton Myriapod A terrestrial arthropod with many body segments and one or two pairs of legs per segment. Millipedes and centipedes are the two major groups of living myriapods Nematocyst In a cnidocyte of a cnidarian, a capsule like organelle containing a coiled thread that when discharged can penetrate the body wall of the prey Open Circulatory System A circulatory system in which fluid called hemolymph bathes the tissues and organs directly and there is no distinction between the circulating fluid and the interstitial fluid Osculum A large opening in a sponge that connects the spongocoel to the environment Pancrustacean A member of a diverse arthropod clade that includes lobsters, crabs, barnacles and other crustaceans, as well as insects and their sixlegged terrestrial relatives Parthenogenesis A form of asexual reproduction in which females produce offspring from unfertilized eggs Pericycle The outermost layer in the vascular cylinder, from which lateral roots arise Planarian A free living flatworm found in ponds and streams Polyp The sessile variant of the cnidarian body plant. The alternate form is the medusa Protonephridium An excretory system, such as the flame bulb system of flatworms, consisting of a network of tubules lacking internal openings Radula A straplike scraping organ used by many molluscs during feeding Spongocoel The central cavity of a sponge Visceral Mass One of the three main parts of a mollusk; the part containing most of the internal organs Water Vascular System A network of hydraulic canals unique to echinoderms that branches into extensions called tube feet, which function in locomotion and feeding Important Facts Porifera (sponges) Lack true tissues; have choanocytes (collar cells – flagellated cells that ingest bacteria and tiny food particles) Cnidaria (hydras, jellies, sea anemones, corals) Unique stinging structures (nematocysts) housed in specialized cells (cnidocytes); diploblastic; radially symmetrical; gastrovascular cavity (digestive compartment with a single opening) Platyhelminthes (flatworms) Dorsoventrally flattened acoelomates; gastrovascular cavity or no digestive tract Rotifera (rotifers) Pseudocoelomates with alimentary canal (digestive tube with mouth and anus); jaws (trophi); head with ciliated crown Lophophorates: Ectoprocta, Brachiopoda Coelomates with lophophores (feeding structures bearing ciliated tentacles) Mollusca (clams, snails, squids) Coelomates with three main body parts (muscular foot, visceral mass, mantle); coelom reduced; most have hard shell made of calcium carbonate Annelida (segmented worms) Coelomates with segmented body wall and internal organs (except digestive tract, which is unsegmented) Nematoda (roundworms) Cylindrical pseudocoelomates with tapered ends; no circulatory system; undergo ecdysis Arthropoda (spiders, centipedes, crustaceans, and insects) Coelomates with segmented body, jointed appendages, and exoskeleton made of protein and chitin Echinodermata (sea stars, sea urchins) Coelomates with bilaterally symmetrical larvae and fivepart body organization as adults; unique water vascular system; endoskeleton Chordata (lancelets, tunicates, vertebrates) Coelomates with notochord; dorsal, hollow nerve cord; pharyngeal slits; postanal tail Chapter 34 Vocabulary Acanthodian Any of a group of ancient jawed aquatic vertebrates from the Silurain and Devonian period Amniotic Egg An egg that contains specialized membranes that function in protection, nourishment and gas exchange. The amniotic egg was a major evolutionary innovation, allowing embryos to develop on land in a fluidfilled sac, thus reducing the dependence of tetrapods on water for reproduction Amphibian A member of the clade of tetrapods that includes salamanders, frogs and caecilians Anthropoid A member of a primate group made up of the monkeys and the apes Apoplast Everything external to the plasma membrane of a plant cell, including cell walls, intercellular spaces, and the space within dead structures such as xylem vessels and tracheids Archosaur A member of the reptilian group that includes crocodiles, alligators and dinosaurs, including birds Chondrichthyan A member of the clade Chondrichthyes, vertebrates with skeletons made mostly of cartilage, such as sharks and rays Chordate A member of the phylum Chordta that at some point during their development have a notochord; a dorsal, hollow nerve cord; pharyngeal silts or clefts; and a muscular, postanal tail Cloaca A common opening for the digestive, urinary and reproductive tracts found in many nonmammalian vertebrates but in few mammals Conodont An early, soft bodied vertebrate with prominent eyes and dental elements Cyclostome A member of the vertebrate subgroup lacking jaws. Cyclostomes include hagfishes and lampreys Diapsid A member of an amniote clade distinguished by a pair of holes on each side of the skull. Diapsids include the lepidosaurs and archosaurs Dinosaur A member of an extremely diverse clade of reptiles varying in body shape, size and habitat. Birds are the only extant dinosaurs Ectothermic Referring to organisms for which external sources provide most of the heat for temperature regulation Endothermic Referring to organisms that are warmed by heat generated by their own metabolism. This heat usually maintains a relatively stable body temperature higher than that of the external environment Eutherian Placental mammal; mammal whose young complete their embryonic development within the uterus, joined to the mother by the placenta Gnathostome A member of the vertebrate subgroup possessing jaws. The gnathostomes include sharks and rays, rayfinned fished, coelacanths, lungfishes, amphibians, reptiles and mammals Hominin A member of the human branch of the evolutionary tree. Hominins include Homo sapiens and our ancestors, a group of extinct species that are more closely related to us than to chimpanzees Lancelet A member of the clade Cephalochordata, small blade shaped marine chordates that lack a backbone Lateral Line System A mechanoreceptor system consisting of a series of pores and receptor units along the sides of the body in fishes and aquatic amphibians; detects water movements made by the animal itself and by other moving objects Lepidosaur A member of the reptilian group that includes lizards, snakes and two species of New Zealand animals called tuataras Lobe Fin A member of the vertebrate clade Sarcopterygii, osteichthyans with rod shaped muscular fins, including coelacanths, lungfishes and tetrapods Mammal A member of the clade Mammalia, amniotes that have hair and mammary glands (glands that produce milk) Marsupial A mammal, such as a koala, kangaroo or opossum whose young complete their embryonic development inside a maternal pouch called the marsupium Monotreme An egg laying mammal, such as a platypus or echidna. Like all mammals, monotremes have hair and produce milk, but they lack nipples Notochord A longitudinal, flexible rod made of tightly packed mesodermal cells that runs along the anteriorposterior axis of a chordate in the dorsal part of the body Operculum In aquatic osteichthyans, a protective bony flap that covers and protects the gills Opposable Thumb A thumb that can touch the ventral surface of the fingertips of all four fingers Osteichthyan A member of a vertebrate clade with jaws and mostly bony skeletons Oviparous Referring to a type of development in which young hatch from eggs laid outside the mother’s body Ovoviviparous Referring to a type of development in which young hatch from eggs that are retained in the mother’s uterus Paleoanthropology The study of human origins and evolution Parareptile A basal group of reptiles, consisting mostly of large, stocky quadrupedal herbivores. Parareptiles died out in the late Triassic period Pharyngeal Cleft In chordate embryos, one of the grooves that separate a series of arches along the outer surface of the pharynx and may develop into a pharyngeal slit Pharyngeal Slit In chordate embryos, one of the slits that form from the pharyngeal clefts and open into the pharynx, later developing into gill slits in many vertebrates Placenta A structure in the uterus of a pregnant eutherian mammal that nourishes the fetus with the mother’s blood supply; formed from the uterine lining and embryonic membranes Placoderm A member of an extinct group of fishlike vertebrates that had jaws and were enclosed in a tough outer armor Pterosaur Winged reptile that lived during the Mesozoic era Ratite A member of the group of flightless birds Ray Finned Fish A member of the clade Actinopterygii, aquatic osteichthyans with fins supported by long, flexible rays, including tuna, bass and herring Reptile A member of the clade of amniotes that includes tuataras, lizards, snakes, turtles, crocodilians and birds Stem Cell Any relatively unspecialized cell that can produce during a single division, one identical daughter cell and one more specialized daughter cell that can undergo further differentiation Suspension Feeder An animal that feeds by removing suspended food particles from the surrounding medium by a capture, trapping or filtration mechanism Swim Bladder In aquatic osteichthyans, an air sac that enables the animal to control its buoyancy in the water Synapsid A member of an amniote clade distinguished by a single hole on each side of the skull. Synapsids include the mammals Tetrapod A vertebrate clade whose members have limbs with digits. Tetrapods include mammals, amphibians and birds and other reptiles Theropod A member of a group of dinosaurs that were bipedal carnivores Tunicate A member of the clade Urochordata, sessile marine chordates that lack a backbone Vertebrate A chordate animal with vertebrae, the series of bones that make up the backbone Viviparous Referring to a type of development in which the young are born alive after having been nourished in the uterus by blood from the placenta Important Facts Cephalochordata (lancelets) Basal chordates; marine suspension feeders that exhibit four key derived characters of chordates Urochordata (tunicates) Marine suspension feeders; larvae display the derived traits of chordates Myxini (hagfishes) Jawless marine vertebrates with reduced vertebrae; have head that includes a skull and brain, eyes, and other sensory organs Petromyzontida (lampreys) Jawless aquatic vertebrates with reduced vertebrae; typically feed by attaching to a live fish and ingesting its blood Chondrichthyes (sharks, rays, skates, ratfishes) Aquatic gnathostomes; have cartilaginous skeleton, a derived trait formed by the reduction of an ancestral mineralized skeleton Actinopterygii (rayfinned fishes) Aquatic gnathostomes; have bony skeleton and maneuverable fins supported by rays Actinistia (coelacanths) Ancient lineage of aquatic lobefins still surviving in Indian Ocean Dipnoi (lungfishes) Freshwater lobefins with both lungs and gills; sister group of tetrapods Amphibia (salamanders, frogs, ceacilians) Have four limbs descended from modified finsl most have moist skin that functions in gas exchange; many live both in water (as larvae) and on land (as adults) Reptilia (tuataras, lizards and snakes, turtles, crocodilians, birds) One of two groups living amniotes; have amniotic eggs and rib cage ventilation, key adaptations for life on land Mammalia (monotremes, marsupials, eutherians) Evolved from synapsid ancestors; include egglaying monotremes (echidnas, platypus); pouched marsupials (such as kangaroos, opossums); and eutherians (placental mammals, such as rodents, primates) Derived characters of humans include bipedalism and a larger brain and reduced jaw compared with other apes Hominins humans and species that are more closely related to humans than to chimpanzees – originated in Africa about 6 million years ago. Early hominins had a small brain but probably walked upright The oldest evidence of tool use is 2.5 million years old Homo ergaster was the first fully bipedal, largebrained hominin Homo erectus was the first hominin to leave Africa Neanderthals lived in Europe and the Near East from about 350,000 to 28,000 years ago Homo sapiens originated in Africa about 195,000 years ago and began to spread to other continents about 115,000 years ago Chapter 40 Vocabulary Acclimatization Physiological adjustment to a change in an environmental factor Adipose Tissue A connective tissue that insulates the body and serves as a fuel reserve; contains fatstoring cells called adipose cells Anatomy The structure of an organism Basal Metabolic Rate (BMR) The metabolic rate of a resting, fasting and nonstressed endotherm at a comfortable temperature Bioenergetics (1) The overall flow and transformation of energy in an organism. (2) The study of how energy flows through organisms Blood A connective tissue with a fluid matrix called plasma in which red blood cells, white blood cells, and cell fragments called platelets are suspended Bone A connective tissue consisting of living cells held in a rigid matrix of collagen fibers embedded in calcium salts Cardiac Muscle A type of striated muscle that forms the contractile wall of the heart. Its cells are joined by intercalated disks that relay the electrical signals underlying each heartbeat Cartilage A flexible connective tissue with an abundance of collagenous fibers embedded in chondroitin sulfate Circadian Rhythm A physiological cycle of about 24 hours that persists even in the absence of external cues Conformer An animal for which an internal condition conforms to (changes in accordance with) changes in an environmental variable Connective Tissue Animal tissue that functions mainly to bind and support other tissues, having a sparse population of cells scattered through an extracellular matrix Countercurrent Exchange The exchange of a substance or heat between two fluids flowing in opposite directions. For example, blood in a fish gill flows in the opposite direction of water passing over the gill, maximizing diffusion of oxygen into and carbon dioxide out of the blood Ectothermic Referring to organisms for which external sources provide most of the heat for temperature regulation Endocrine System In animals, the internal system of communication involving hormones, the ductless glands that secrete hormones, and the molecular receptors on or in target cells that respond to hormones; functions in concert with nervous system to effect internal regulation and maintain homeostasis Endothermic Referring to organisms that are warmed by heat generated by their own metabolism. This heat usually maintains a relatively stable body temperature higher than that of the external environment Epithelial Tissue Sheets of tightly packed cells that line organs and body cavities as well as external surfaces Epithelium An epithelial tissue Fibroblast A type of cell in loose connective tissue that secretes the protein ingredients of the extracellular fibers Glia (Glial Cells) Cells of the nervous system that support, regulate, and augment the functions of neurons Hibernation A longterm physiological state in which metabolism decreases, the heart and respiratory system slow down, and body temperature is maintained as a lower level than normal Homeostasis The steadystate physiological condition of the body Integumentary System The outer covering of a mammal’s body, including skin, hair, and nails, claws, or hooves Interstitial Fluid The fluid filling the spaces between cells in most animals Ligament A fibrous connective tissue that joins bones together at joints Macrophage A phagocytic cell present in many tissues that functions in innate immunity by destroying microbes and in acquired immunity as an antigenpresenting cell Metabolic Rate The total amount of energy an animal uses in a unit of time Muscle Tissue Tissue consisting of long muscle cells that can contract, either on its own or when stimulated by nerve impulses Negative Feedback A form of regulation in which accumulation of an end product of a process slows the process; in physiology, a primary mechanism of homeostasis, whereby a change in a variable triggers a response that counteracts the initial change Nervous System In animals, the fastacting internal system of communication involving sensory receptors, networks of nerve cells, and connections to muscles and glands that respond to nerve signals; functions in concert with endocrine system to effect internal regulation and maintain homeostasis Nervous Tissue Tissue made up of neurons and supportive cells Neuron A nerve cell; the fundamental unit of the nervous system, having structure and properties that allow it to conduct signals by taking advantage of the electrical charge across its plasma membrane Organ System A group of organs that work together in performing vital body functions Physiology The processes and functions of an organism Positive Feedback A form of regulation in which an end product of a process speeds up that process; in physiology, a control mechanism in which a change in a variable triggers a response that reinforces or amplifies the change Regulator An animal for which mechanisms of homeostasis moderate internal changes in a particular variable in the face of external fluctuation of the variable Sensor In homeostasis, a receptor that detects a stimulus Set Point In homeostasis in animals, a value maintained for a particular variable, such as body temperature or solute concentration Skeletal Muscle A type of striated muscle that is generally responsible for the voluntary movements of the body Smooth Muscle A type of muscle lacking the striations of skeletal and cardiac muscle because of the uniform distribution of myosin filaments in the cells; responsible for involuntary body activities Standard Metabolic Rate (SMR) Metabolic rate of a resting, fasting, and nonstressed ectotherm at a particular temperature Statolith A dense particle that settles in response to gravity and is found in sensory organs that function in equilibrium Tendon A fibrous connective tissue that attaches muscle to bone Thermoregulation The maintenance of internal body temperature within a tolerable range Tissue An integrated group of cells with a common structure, function, or both Torpor A physiological state in which activity is low and metabolism decreases Important Facts Physical laws constrain the evolution of an animal’s size and shape. These constraints contribute to convergent evolution in animal body forms Each animal cell must have access to an aqueous environment. Simple twolayered sacs and flat shapes maximize exposure to the surrounding medium. More complex body plans have highly folded internal surfaces specialized for exchanging materials. Animal bodies are based on a hierarchy of cells, tissues, organs, and organ systems. Epithelial tissue forms active interfaces on external and internal surfaces; connective tissue binds and supports other tissues; muscle tissue contracts, moving body parts; and nervous tissue transmits nerve impulses throughout the body The endocrine and nervous systems are the two means of communication between different location in the body. The endocrine system broadcasts signaling molecule called hormones everywhere via the bloodstream, but only certain cells are responsive to each hormone. The nervous system uses dedicated cellular circuits involving electrical and chemical signals to send information to specific locations Animals regulate (control) certain internal variables while allowing other internal variables to conform to external changes. Homeostasis is the maintenance of a steady state despite internal and external changes Homeostatic mechanisms are usually based on negative feedback, in which the response reduces the stimulus. In contrast, positive feedback involves amplification of a stimulus by the response and often brings about a change in state, such as the transition from pregnancy to childbirth Regulated change in the internal environment is essential to normal function. Circadian rhythms are daily fluctuations in metabolism and behavior turned to the cycles of light and dark in the environment. Other environmental changes may trigger acclimatization, a temporary shift in the steady state. An animal maintains its internal temperature within a tolerable range by thermoregulation. Endotherms are warmed mostly by heat generated by metabolism. Ectotherms get most of their heat from external sources. Endothermy requires a greater expenditure of energy, body temperature may vary with environmental temperature, as in poikilotherms, or be relatively constant, as in homeotherms. In thermoregulation, physiological and behavioral adjustments balance heat gain and loss, which occur through radiation, evaporation, convection, and conduction. Insulation and countercurrent exchange reduce heat loss, whereas panting, sweating and bathing increase evaporation, cooling the body. Many ectotherms and endotherms adjust their rate of heat exchange with their surroundings by vasodilation or vasoconstriction and by behavioral responses Many mammals and birds adjust their amount of body insulation in response to changes in environmental temperature. Ectotherms undergo a variety of changes at the cellular level to acclimatize to shifts in temperature The hypothalamus acts as the thermostat in mammalian regulation of body temperature. Fever reflects a resetting of this thermostat to a higher range in response to infection Animals obtain chemical energy from food, storing it for short term use in ATP. The total amount of energy used in a unit of time defines an animal’s metabolic rate. Under similar conditions and for animals of the same size, the basal metabolic rate of endotherms is substantially higher than the standard metabolic rate of ectotherms. Minimum metabolic rate per gram is inversely related to body size among similar animals. Animals allocate energy for basal (or standard) metabolism, activity, homeostasis, growth and reproduction. Torpor, a state of decreased activity and metabolism, converses energy during environmental extremes. Animals may enter torpor during sleep periods (daily torpor), in winter (hibernation), or in summer (estivation) Chapter 41 Vocabulary Absorption The third stage of food processing in animals: the uptake of small nutrient molecules by an organism’s body Alimentary Canal A complete digestive tract, consisting of a tube running between a mouth and an anus Amylase An enzyme that hydrolyzes starch (a glucose polymer from plants) and glycogen (a glucose polymer from animals) into smaller polysaccharides and the disaccharide maltose Appendix A small, fingerlike extension of the vertebrate cecum; contains a mass of white blood cells that contribute to immunity Bile A mixture of substances that is produced in the liver and stored in the gallbladder; enables formation of fat droplets in water as an aid in the digestion and absorption of fats Bolus A lubricated ball of chewed food Bulk Feeder An animal that eats relatively large pieces of food Carnivore An animal that mainly eats other animals Cecum The blind pouch forming one branch of the large intestine Chylomicron A lipid transport globule composed of fats mixed with cholesterol and coated with proteins Chyme The mixture of partially digested food and digestive juices formed in the stomach Colon The largest section of the vertebrate large intestine; functions in water absorption and formation of feces Community All the organisms that inhabit a particular area; an assemblage of populations of different species living close enough together for potential interaction Diabetes Mellitus An endocrine disorder marked by an inability to maintain glucose homeostasis. The type 1 form results from autoimmune destruction of insulinsecreting cells; treatment usually requires daily insulin injections. The type 2 form most commonly results from reduced responsiveness of target cells to insulin; obesity and lack of exercise are risk factors. Digestion The second stage of food processing in animals: the breaking down of food into molecules small enough for the body to absorb Duodenum The first section of the small intestine, where chime from the stomach mixes with digestive juices from the pancreas, liver, and gallbladder as well as from gland cells of the intestinal wall Elimination The fourth and final stage of food processing in animal: the passing of undigested material out of the body Esophagus A muscular tube that conducts food, by peristalsis, from the pharynx to the stomach Essential Amino Acid An amino acid that an animal cannot synthesize itself and must be obtained from food in prefabricated form Essential Fatty Acid An unsaturated fatty acid that an animal needs but cannot make Essential Nutrient A substance that an organism cannot synthesize from any other material and therefore must absorb in preassembled form Feces The wastes of the digestive tract Filter Feeder An animal that feeds by using a filtration mechanism to strain small organisms or food particles from its surroundings Fluid Feeder An animal that lives by sucking nutrientrich fluids from another living organism Gallbladder An organ that stores bile and releases it as needed into the small intestine Gastric Juice A digestive fluid secreted by the stomach Gastrovascular Cavity A central cavity with a single opening in the body of certain animals, including cnidarians and flatworms, that functions in both the digestion and distribution of nutrients Glucagon A hormone secreted by pancreatic alpha cells that raises blood glucose levels. It promotes glycogen breakdown and release of glucose by the liver Hepatic Portal Vein A large vessel that conveys nutrientladen blood from the small intestine to the liver, which regulates the blood’s nutrient content Herbivore An animal that mainly eats plants or algae Ingestion The first stage of food processing in animals: the act of eating Insulin A hormone secreted by pancreatic beta cells that lowers blood glucose levels. It promotes the uptake of glucose by most body cells and the synthesis and storage of glycogen in the liver and also stimulates protein and fat synthesis. Lacteal A tiny lymph vessel extending into the core of an intestinal villus and serving as the destination for absorbed chylomicrons Large Intestine The portion of the vertebrate alimentary canal between the small intestine and the anus; functions mainly in water absorption and the formation of feces Liver A large internal organ in vertebrates that performs diverse functions, such as producing bile, maintaining blood glucose level, and detoxifying poisonous chemicals in the blood Microvillus One of many fine, fingerlike projections of the epithelial cells in the lumen of the small intestine that increase its surface area Mineral In nutrition, a simple nutrient that is inorganic and therefore cannot be synthesized in the body Mucus A viscous and slippery mixture of glycoproteins, cells, salts and water that moistens and protects the membranes lining body cavities that open to the exterior Nutrition The process by which an organism takes in and makes use of food substances Omnivore An animal that regularly eats animals as well as plants or algae Oral Cavity The mouth of an animal Pancreas A gland with exocrine and endocrine tissues. The exocrine portion functions in digestion, secreting enzymes and an alkaline solution into the small intestine via a duct; the ductless endocrine portion functions in homeostasis, secreting the hormones insulin and glucagon into the blood. Partial Pressure The pressure exerted by a particular gas in a mixture of gases Pepsin An enzyme present in gastric juice that begins the hydrolysis of proteins Pepsinogen The inactive form or pepsin secreted by chief cells located in gastric pits of the stomach Peristalsis (1) Alternating waves of contraction and relaxation in the smooth muscles lining the alimentary canal that push food along the canal. (2) A type of movement on land produced by rhythmic waves of muscle contractions passing from front to back, as in many annelids. Pharynx (1) An area in the vertebrate throat where air and food passages cross. (2) In flatworms, the muscular tube that protrudes from the ventral side of the worm and ends in the mouth Protease An enzyme that digests proteins by hydrolysis Rectum The terminal portion of the large intestine, where the feces are stores prior to elimination Salivary Gland A glad associated with the oral cavity that secretes substances that lubricate food and begin the process of chemical digestion Small Intestine The longest section of the alimentary canal, so named because of its small diameter compared with that of the large intestine; the principal site of the enzymatic hydrolysis of food macromolecules and the absorption of nutrients Sphincter A ringlike band of muscle fibers that controls the size of an opening in the body, such as the passage between the esophagus and the stomach Sticky End A single stranded end of a double stranded restriction fragment Stomach An organ of the digestive system that stores food and performs preliminary steps of digestion Substrate Feeder An animal that lives in or on its food source, eating its way through the food Villus (1) A fingerlike projection of the inner surface of the small intestine. (2) A fingerlike projection of the chorion of the mammalian placenta. Large numbers of villi increase the surface areas of these organs. Vitamin An organic molecule required in the diet in very small amounts. Many vitamins serve as coenzymes or parts of coenzymes Important Facts Animals have diverse diets. Herbivores mainly eat plants; carnivores mainly eat other animals; and omnivores eat both. In meeting their nutritional needs, animals must balance consumption, storage and use of food Food provides animals with energy for ATP production, carbon skeletons for biosynthesis, and essential nutrients – nutrients that must be supplied in preassembled form. Essential nutrients include certain amino acids and fatty acids that animals cannot synthesize; vitamins, which are organic molecules; and minerals, which are inorganic substances Animals can suffer from two types of malnutrition: an inadequate intake of essential nutrients and a deficiency in sources of chemical energy. Studies of disease at the population level help researchers determine human dietary requirements Stages of food processing: (1) Ingestion (eating); (2) Digestion (enzymatic breakdown of large molecules); (3) Absorption (uptake of nutrients by cells); Elimination (passage of undigested materials out of the body in feces) Animals differ in the ways they obtain and ingest food. Many animals are bulk feeders, eating large pieces of food. Other strategies include filter feeding, suspension feeding, and fluid feeding. Compartmentalization is necessary to avoid selfdigestion. In intracellular digestion, food particles are engulfed by endocytosis and digested within food vacuoles that have fused with lysosomes. In extracellular digestion, which is used by most animals, enzymatic hydrolysis occurs outside cells in a gastrovascular cavity or alimentary canal. Vertebrate digestive systems display many evolutionary adaptations associated with diet. For example, dentition, which is the assortment of teeth, generally correlates with diet. In a form of mutualism, many herbibores, including cows, have fermentation chambers where microorganisms digest cellulose. Herbivores also usually have longer alimentary canals than carnivores, reflecting the longer time needed to digest vegetation Nutrition is regulated at multiple levels. Food in the alimentary canal triggers nervous and hormonal responses that control the secretion of digestive juices and that promote the movement of ingested material through the canal. The availability of glucose for energy production is regulated by the hormones insulin and glucagon, which control the synthesis and breakdown of glycogen. Vertebrates store excess calories in glycogen (in liver and muscle cells) and in fat (in adipose cells). These energy stores can be tapped when an animal expends more calories than it consumes. If, however, an animal consumes more calories than it needs for normal metabolism, the resulting overnourishment can lead to the serious health problem of obesity. Several hormones, including leptin and insulin, regulate appetite by affecting the brain’s satiety center
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