Unit 3 Study Guide
Unit 3 Study Guide BIO 311D
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This 33 page Study Guide was uploaded by Liam Murphy on Sunday April 10, 2016. The Study Guide belongs to BIO 311D at University of Texas at Austin taught by Dr. Mark Bierner in Winter 2016. Since its upload, it has received 143 views. For similar materials see Introductory Biology II in Biology at University of Texas at Austin.
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Test 3: Study Guide Sections 32.1 and 34.5 Being an Animal; Being Terrestrial Vocab: Tissues: any of the distinct types of material of which animals or plants are made, consisting of specialized cells and their products. Cleavage: succession of mitotic cell divisions without cell growth between divisions Blastula: hollow ball Gastrulation: layers of embryonic tissues that will develop into adult body parts are produced and results in a gastrula Larva: the active immature form of an insect, especially one that differs greatly from the adult and forms the stage between egg and pupa, e.g., a caterpillar or grub. Metamorphosis: developmental transformation that turns the animal into a juvenile that resembles an adult, but is not yet sexually mature Hox genes: group of related genes that control the body plan of an embryo along the cranio-caudal, regulate formation of anterior- posterior axis along with other aspects of development Ediacaran biota: soft-bodied multicellular eukaryotes Amniotes: a group of tetrapods whose extant members are the reptiles (including birds) and mammals Clade: a group of organisms believed to have evolved from a common ancestor, according to the principles of cladistics. Amniotic egg: contains four specialized membranes including the amnion, chorion, yolk sac, and allantois Ectothermic: absorb external heat as their main source of body heat Endothermic: capable of maintaining body temperature through metabolic activity Parareptiles: large, stocky, quadrupedal herbivores, died around 200 million years ago Diapsids: pair of holes on each side of the skull, behind the eye sockets, muscles pass through these holes and attach to the jaw controlling jaw movement Lepidosaurs: branch of diapsids including tuataras, lizards, and snakes, some marine reptiles too Archosaurs: branch of diapsids including crocodilians, pterosaurs, and dinosaurs Pterosaurs: originated late in the Triassic age, first tetrapods to exhibit flapping flight, collagen strengthened membrane that stretched between trunk or hind leg and a very long digit on the foreleg Ratites: ostrich, rhea, kiwi, cassowary, and emu; flightless birds Key Concepts: Animals are multicellular, heterotrophic eukaryotes with tissues that develop from embryonic layers. Amniotes are tetrapods that have a terrestrially adapted egg. Although some animals, including humans, develop directly into adults, the life cycles of most animals include at least one larval stage. The amniotes are a group of tetrapods whose extant members are the reptiles (including birds) and mammals. Take a look at the next slide (slide 29) Amniotes are named for the major derived character of the clade, the amniotic egg Phylogenetic analyses of birds and reptilian fossils indicate that birds belong to the group of bipedal saurischian dinosaurs called theropods (Tyrannosaurus rex is a member of this group). Questions: How do plants get their food? o Photosynthesis → make their own food o Autotrophic eukaryotes How do fungi get their food o Decomposers o Put out enzymes and break down food around them, through external digestion o Heterotrophs that can grow on or near food and that feed by absorption o They don't need a digestive system like we do o Must get food somehow through external source (same as animals) How do animals get their foods? o Internal digestion o We have to go out and get out food and ingest it Take in things that we can’t digest (digestive system) o Ingest food and then use enzymes to digest within our bodies What is there about cell structures that differentiates animals from plants and fungi? o At the cellular level → cell wall, central vacuole o No cell wall in animals, no central vacuole in animals o Variety of proteins external to the cell membrane provide structural support to animal cells and connect them Animals have collagen instead of cell walls Muscle and nerve cells are central to the animal lifestyle If the cell wall provides structural support to plant and fungal cells and connects them to one another, what is the major thing that provides structural support to animal cells and connects them to one another? o Extracellular matrix → its proteins are on the outer surface of the plasma membrane; microtubules Collagen is a central molecule that gives rigidity to the cell kind of like the cell wall does Animals have two types of specialized cells not found in other multicellular organisms. What are they? o Nerve cells and muscle cells What are tissues? What are the tissues into which these cells are organized and what do these tissues do? o Tissues are groups of similar cells that act as a functional unit o Cells to tissues to organs to organ systems o Groups of cells that have a common structure, function, or both o Muscle and nervous tissue move the body and conduct nerve impulses o Ability to move and conduct nerve impulses is an adaptation that differentiates animals from plants and fungi Tell me about what is happening during early embryonic development in animals? o Identical twins→ zygote, then mitosis, then symmetrical division of the egg o Stages: zygote → 8-cell stage → blastula → gastrulation (now you have blastocoel, endoderm, ectoderm, archenteron, and blastopore) o In haploid stage, sperm and egg are produced directly by meiotic division o Sperm fertilizes egg, sperm and egg make zygote, zygote undergoes cleavage, cleavage leads to formation of blastula (hollow ball of cells surrounding the blastocoel), blastula stage is followed by gastrulation (one end of the embryo folds inward, expands, and fills blastocoel producing layers of embryonic tissues), body parts formed and is called a gastrula; archenteron opens to the outside via blastopore, ectoderm develops into the tissue lining of the digestive tract. What is a larva? o The sexually immature form of an insect, especially one that differs greatly from the adult and forms the stage between egg and pupa, e.g., a caterpillar or grub o Morphological differences, eats different food, possibly different habitats What is the development transformation by which an animal larva turns into a juvenile that resembles an adult but is not yet sexually mature? o Metamorphosis We will cover Hox genes in more detail at another time, but what in general are Hox genes? o Homeotic genes that produce/control the body plane, where parts are located on a body and the development of those parts in the right places o group of related genes that control the body plan of an embryo along the cranio-caudal o Plants → matchbox, animals → hox o Gene products → they code for transcription factors (which then control the turning on and off of other genes that control the production of other parts on the body) o Basically master control genes o Control the expression of dozens or even hundreds of other genes that influence animal morphology in the development of animal embryos What does the origin of multicellularity require? o Evolution of new ways for cells to adhere (attach) and signal (communicate) to each other What is a clade? o A group of organisms believed to have evolved from a common ancestor, according to the principles of cladistics. Give some adaptations that amniotes have undergone. o Amniotic egg o Rib cage used to ventilate lungs What is an amniotic egg? What are the four specialized membranes that surround the embryo? o Amphibians need to live near water Gas exchange: occurring--for most--through their skin Need to be near mostly wet areas o Reptiles: scale skin o Amniotes do not need to do this Moving air in and out of the organism, solves problems of how you do gas exchange with water proof skin and have an egg that does not require water Big adaptations → but the youngest stages you still need to be wet but this is possible with the amniotic sac o 4 membranes: 1. Amnion: encloses a compartment of fluid that bathes the embryo and acts as a hydraulic shock absorber 2. Chorion: exchange gases between embryo and air 3. Yolk sac: nutrients 4. Allantois: disposal sac for certain metabolic wastes produced by the embryo Why are they called extraembryonic membranes: o Because they are not part of the body of the embryo itself, these membranes develop from tissue layers that grow out from the embryo o Named for the amnion What are the main functions of amnion, amniotic cavity, and amniotic fluid? o Protection What are the functions of the allantois and the membrane of allantonis o Taking in things o Places to put waste → waste storgae (keeps away from everything else so you don’t ruin the embryo) What is the function of the yoke sac and yoke? o Provide nutrition What did Hylonomus(reptiles) have that amphibians do not? o Scaly covering, sharp teeth o Amphibians are restricted to wet areas due to the inability to protect their water in skin What are a couple of other characteristics of early amniotes? o Warm, moist environments, dry and high-latitude environments, sharp teeth, small, predatory What distinguished synapsids from diapsids? o Synapsids (humans) only have one opening behind eye socket and has to do with anchoring muscles that articulate the jaw o Diapsids have two openings behind eye/jaw What are some unifying characteristics of reptiles? o Lay eggs not in water o Cold blooded, so they can not control their body temperature internally, they need other things to protect them o For an endotherm (people) metabolism creates heat Takes more energy to maintain an endotherm than an exotherm Costs more energy, but you can adjust to temp. What about skin of reptiles? o Scaly skin made of keratin (in humans, keratin located in nails and hair) Where do most of them lay their eggs? o On land, fertilization occurs internally before eggshell is secreted How about how they control their body temperature? o Ectothermic/cold-blooded (absorb external heat as their main source of body heat) o Temperature regulation controlled by surroundings of environment o Metabolically, it takes less energy to be an ectotherm versus endotherm Looking strictly at the reptiles in the following diagram, what do parareptiles represent? o How about the skull? o Skull of diapsids contain a pair of holes on each side of the skull behind the eye sockets How do birds fit in? o Pterosaurs may be linked to some of the convergent ecological roles played by later birds, but theropods are the ancestors of birds What are the two major lineages of the reptiles? o Diapsids o Parareptiles What are the two major lineages of the diapsids? o Archosaurs o Lepidosaurs What do you see in the diapsid lineage? o Pair of holes on each side of the skull behind eye sockets o Led to archosaurs (crocodilians, pterosaurs, and dinosaurs) and lepidosaurs (tuataras, lizards, and snakes) What are the lepidosaurs? o Tuataras and squamates (lizards and snakes) o Some marine animals What are the archosaurs? o Crocodilians, pterodactyls, dinosaurs What is this thing? o Tuatara → Lizard So squamates include? o Australian thorny devil lizard and wagler’s pit viper Turtles are a very large group of reptiles, but what are they related to? o Ancestral to crocodiles and birds? o See the three hypotheses o May be sister group to parareptiles, could be diapsids more closely related to lepidosaurs, or to archosaurs What do all turtles have? o Boxlike shell made of upper and lower shields that are fused to the vertebrae, clavicles, and ribs How do crocodilians fit into the grand scheme of reptile evolution? o Belong to a lineage that reaches back to the late Triassic o Earliest members of the lineage were small terrestrial quadrupeds with long, slender legs and later became adapted to aquatic environments So birds are classified as dinosaurs o Wow!!! Lol o They are considered archosaurs What are the adaptations in birds associated with? o Flight Premium on weight-saving modifications for flight include o Lack of urinary bladder o Only one ovary in the females of most species o Small gonads in both males and females o Lack of teeth What is a wing as far as overall general structure is concerned? o Shape and arrangement of feathers form the wings into airfoils and use the same principles of aerodynamics as the wings of an airplane o Remodeled version of the tetrapod forelimb What are feathers composed of? Where else is that found? o Protein Beta-keratin, also found in the scales of other reptiles What does internal structure of bones have to do with anything? o Honeycombed internal structure filled with air that makes the bones very light, thus easier to fly What does internal structure of feathers have to do with anything? o Consists of a central air-filled shaft, from which radiate the vanes o Vanes are made up of barbs, which bear small branches called barbules o Contour feathers and downy feathers What are contour feathers? o Stiff and contribute to the aerodynamic shapes of the wings and body o The barbules have hooks that cling to barbules on neighboring barbs What are downy feathers? o Lack hooks and the free-form arrangement of barbs produces a fluffiness that provides insulation by trapping air Archaeopteryx is the earliest known bird. What are some of it’s characteristics that relate it to both dinosaurs and birds? o Teeth, vertebrae in long tail, clawed digits o It flew well at high speeds, but could not take off from standing position Give examples of flightless birds. o Ratites-ostrich, rhea, kiwi, cassowary Flying birds show great diversity in their adaptations. What do you see in the following slides? o Hummingbird (unique skeleton wing, can hover and fly backwards), flamingo (filter eater), and foot structure (perching, grasping, swimming, walking, and courtship) o Penguins have super strong pectoral muscles, but cannot fly in the air Sections 34.6 and 34.7 Mammals and Hominins Vocab: Synapsids: group of amniotes that mammals are in Placenta: structure in which nutrients diffuse into the embryo from the mother’s blood Convergent evolution: Marsupium: maternal pouch i.e. kangaroos Marsupial: opossums, kangaroos, koalas, high metabolic rates, nipples that provide milk, give birth to live young Monotremes: found only in Australia and New Guinea, represented by one species of platypus and four species of echidnas, they lay eggs, have hair, produce milk, and lack nipples, milk is secreted by glands on the belly of the mother Eutherians: commonly called placental mammals, longer pregnancy Opposable thumb: thumb that can touch the ventral surface of the tip of all four fingers with the ventral surface of the thumb of the same hand Anthropoids: includes monkeys and apes, found worldwide Paleoanthropology: study of human origins Hominins: twenty extinct species that are more closely related to humans than chimps Sahelanthropus tchadensis: earliest hominin from 6.5 million years ago Key concepts: Mammals are amniotes that have hair and produce milk Humans are mammals that have a large brain and bipedal locomotion Mammals belong to a group of amniotes known as synapsids. The greatest diversity of marsupials is in Australia, which has not been in contact with another continent for about 65 million years. In Australia, convergent evolution has resulted in a diversity of marsupials that resemble eutherians in similar ecological roles in other parts of the world. Two major trends developed during the evolution of Australopiths: complete bipedalism and tool use Questions: What are the major derived characters of mammals that distinguish them from the other amniotes? o Mammary glands, hair, fat layer under skin, endothermic, high metabolic rate, four chambered heart, diaphragm, larger brains, capable learners, duration of parental care, differentiated teeth What does hair and a fat layer under the skin do for mammals? o Warmth via insulation by retaining heat What about the production of milk in mammary glands? o Antibodies, good bacteria in the milk, proteins How about brain size? o Larger brain than other vertebrates of equivalent size, capable learners How about the duration of parental care? o Relatively long duration of parental care extends the time for offspring to learn important survival skills by observing parents How about teeth? o Humans can cut and grind (omnivore teeth) o Differentiated teeth allow for chewing many types of food What group of amniotes do mammals belong to? o Synapsids What are synapsids? o Group of amniotes, single temporal fenestra (a hole behind the eye socket on each side of the skull) o Evolved into large herbivores and carnivores during Permian period Without going into details, what are these lineages? o Monotremes (egg-laying mammals) o Marsupials (mammals with a pouch) o Eutherians (placental mammals) What are the characteristics of monotremes? o Lay eggs i.e. echidna and platypus o Hair and produce milk but mammary glands do not have nipples What are the main ways in which marsupials and eutherians differ from monotremes? o Young start off in uterus versus starting in an egg o Mammary glands with nipples, higher metabolic rates, give birth to live young Along with lining of uterus, what do the extraembryonic membranes that arise from the embryo form in marsupials and eutherians? o Marsupials do have a placenta, but it is much more reduced o Placentas arise from extraembryonic membranes from embryo What is a marsupium, and how does the birth of marsupials differ from the birth of eutherians? o Marsupial young do not stay in uterus for long because they migrate to the pouch o Eutherian young are in the uterus and then are born and survive on their own What is convergent evolution? (See slide 26) o Animals that occupy similar niches (thing of how something fits in, includes habitat and what something is near) o In australia, convergent evolution has resulted in a diversity of marsupials that resemble eutherians in similar ecological roles in other parts of the world How do eutherians differ from marsupials? o No pouch, so young go through early development in uterus o Eutherian placenta provides an intimate and long-lasting association between the mother and her developing young Are marsupials and eutherians more or less related to each other than monotremes? o Marsupials and eutherians are more closely related to one another than either is to monotremes o Molecular evidence indicates that marsupials and eutherians are more closely related to one another than either is to monotremes. What are the major derived characters of primates? o Many have to do with the structure of hands and feet How about finger and toe nails? o Flat fingers and toe nails o Skin ridges on fingers How about grasping? o Due to the fact that they were tree-dwelling How about the big toe and the thumb? o Thumb and big toe are distinctly different than the other fingers and toes o Opposable thumb How about the brain and jaw and the shape of the face? o Brain is getting larger o Jaw and face move back and get flatter, shorter jaws How about overlapping visual fields? o Gives depth perception, hand-eye coordination o Eyes are closer together on the front of the face, looking forward How about parental and social behavior? o More care of the young, which improves fitness and chance of survival o Period of learned behavior and passing on of knowledge o Well developed parental care and complex social behavior Tell me about the phylogenetic tree of primates in the next slide? (Pg 740) o Fossil record indicates that anthropoids began diverging from other primates about 55 million years ago o New World Monkeys, Old World Monkeys, and apes have been evolving as separate lineages for more than 25 million years o Lineages leading to humans branched off from other apes sometime between 6 and 7 million years ago What are the three main groups of living primates? o Lemurs (early arboreal primates) o Tarsiers o Anthropoids (monkeys and apes) Are tarsiers more closely related to lemur group or anthropoids? o Anthropoids What are the differences between Old World Monkeys and New World Monkeys? o All New World Monkeys are arboreal o Old World Monkeys are ground-dwelling and arboreal o Both groups of diurnal and live in bands held together by social behavior Major differences between humans and non-human anthropoids include o Use of opposable thumb (humans use for dexterity, non-human anthropoids use for power grip) What are anthropoids? o New World Monkeys (spider monkey), Old World Monkeys (macaque), Gibbons, Orangutans, Gorillas, Chimpanzees, Bonobos, and Humans o Essentially monkeys and apes How old are homo sapiens? o About 200,000 years old How about the mode of locomotion? o Bipedal locomotion (shows up very early in human lineage) o Humans stand upright How about brain size and capabilities that come along with having a larger brain? o Brain size increases throughout human lineage o Reasoning and communication o Capable of language, symbolic thought, artistic expression, and manufacture and use of complex tools How about the jawbone and jaw muscles? o Less pronounced and less strong, reduced jawbones and jaw muscles o More omnivorous existence How about the digestive tract? o Shorter digestive tract How about expression of regulatory genes? o 99% identical, but the 1% difference can translate into a large number of changes in a genome that contains 3 billion base pairs i.e. changes in a small number of genes can have large effects o Humans and chimpanzees differ in the expression of 19 regulatory genes, which turn other genes on and off What are hominins? o Distinguishes humans from other anthropoids o Twenty extinct species that are more closely related to humans than chimps What characteristics made early hominins such as Sahalanthropus tchadensis and Ardipithicus ramidus more human-like than chimpanzee-like? o Reduced canine teeth, relatively flat faces, stood more upright and bipedal than other apes, foramen magnum located underneath the skull How about their canine teeth and shape of the faces? o Reduction in canine teeth o Flatter face How about their mode of locomotion? What does the foramen magnum have to do with this? o Foramen magnum in early humans was located underneath the skull, which allowed them to hold their heads directly over their bodies On the flip side, what were some of the more “primitive” characteristics of the early hominins? o Brains remained small, as did their overall size, larger teeth, projected jaw How about their brains? o Smaller How about their overall size? o Smaller How about their teeth and jaws? o Large molars for grinding o Projecting jaw What’s a common misperception relating to the evolution of hominins and the evolution of chimpanzees? o Chimpanzees represent the tip of a separate branch of evolution, and they acquired derived characters of their own after they diverged from their common ancestor with humans What’s a common misperception relating to the evolution of homo sapiens? o Homo sapiens appears not as the end result of a straight evolutionary path, but rather as the only surviving member of a highly branched evolutionary tree o It did not go right from ancestral ape to homo sapiens What does this look like? (slide 72) o It looks as though human evolution is a parade (not true) What two major trends developed during evolution of Australopiths? o Complete bipedalism and tool use What was the first group to originate out of Africa and to migrate out of Africa? o Homo erectus Know the rest of the information from this power point, besides 106!!! o 2.4 million years ago, first members of genus Homo appeared (homo habilis and homo rudolfensis) They had larger brain volumes and shorter jaws than the Australopiths. They also used more tools o 2 million years ago, homo ergaster appeared in Africa o 2 million years ago, homo erectus appeared in Africa, then Europe, Asia, and South Pacific They were taller than earlier hominins and had longer legs with larger brains Used fire to cook food and keep warm along with stone tools o Out-of-Africa hypothesis Initially, hominins colonized the Old World as homo erectus around 2 million years ago, and a second time as homo sapiens about 120,000 years ago Essentially, homo sapiens emerged in Africa and then in a second wave of colonization, they replaced the premodern hominins (homo erectus, homo heidelbergensis, and homo neanderthalensis) of Europe and Asia 600,000 years ago, there was another migration and colonization Homo heidelbergensis evolved from African homo erectus/homo ergaster about 800,000 years ago Some moved to Europe and others stayed in Africa Predicts premodern hominin populations in Europe and Asia died out without giving anything to modern human gene pool All modern humans are descended from premodern humans (homo erectus/homo ergaster) in Africa alone 350,000 to 28,000 years ago Homo neanderthalensis was present in Europe and Central Asia Evolved from European populations of homo heidelbergensis Neanderthals were heavier, stronger, stockier, and had a more pronounced brow ridge, but shared many social/cultural characteristics with modern humans 195,000 years ago, homo sapiens evolved from African populations of homo heidelbergensis The homo sapiens and other homo species coexisted for thousands of years in different areas 50,000 years ago, homo sapiens developed new behavioral and cultural traits, language was developed Homo sapiens became physiologically and culturally fully modern Rapidly replaced other homo species around the globe 28,000 years ago, all other homo species gone except for homo floresiensis o DNA analyses indicate that all living humans are more closely related to one another than to Neanderthals Sections 40.1 and 40.2 Animal Form and Function Vocab: Anatomy: biological form Physiology: biological function Interstitial fluid: spaces between cells are filled with this type of fluid Tissues: cells are organized into groups of cells with similar appearance and common function Organs: different types of tissue are further organized into functional units Organ system: groups of organs that work together, providing an additional level of organization and coordination Epithelial tissues: also known as epithelia, cover the outside of the body and line organs and cavities within the body, function as a barrier against mechanical injury, pathogens, and fluid loss Connective tissue: consists of a sparse population of cells scattered through an extracellular matrix and holds many tissues and organs together and in place, consists of fibroblasts, macrophages, tendons, ligaments, cartilage, adipose tissue, bone, and blood Fibroblasts: secrete fiber proteins Macrophages: engulf foreign particles and any cell debris by phagocytosis Tendon: attach muscles to bones Ligament: connect bones at joints Bone: mineralized connective tissue including osteoblasts and osteons Blood: has a liquid extracellular matrix called plasma, which consists of water, salts, and dissolved proteins Adipose tissue: specialized loose connective tissue that stores fat in adipose cells distributed throughout its matrix, insulates the body and stores fuel as fat molecules Cartilage: contains collagenous fibers embedded in a rubbery protein- carbohydrate complex called chondroitin sulfate Muscle tissue: responsible for all types of body movement, contains proteins actin and myosin, both voluntary and involuntary movement Skeletal muscle: attached to bones by tendons, striated muscle, voluntary movement Smooth muscle: lacks striations, walls of digestive tract, urinary bladder, arteries, and other internal organs, spindle-shaped, involuntary actions Cardiac muscle: wall of heart, striated, intercalated discs Nervous tissue: functions in the receipt, processing, and transmission of information Neurons: nerve cells, transmit nerve impulses Glial cells: support cells, help nourish, insulate and replenish neurons, modulate neuronal function Endocrine system: signaling molecules released into bloodstream by endocrine cells are carried to all locations in the body Nervous system: neurons transmit signals along dedicated routes connecting specific locations in the body Hormones: signaling molecules broadcast throughout the body by endocrine system Regulator: uses internal mechanisms to control internal change in the face of external fluctuation Conformer: allows its internal conditions to change in accordance with external changes in the variable Homeostasis: steady state, maintenance of internal balance Response: a physiological activity that helps return the variable to the set point Negative feedback: control mechanism that reduces or damps the stimulus Positive feedback: control mechanism that amplifies rather than reduces the stimulus Circadian rhythm: set of physiological changes that occur roughly every 24 hours Acclimatization: gradual process by which an animal adjusts to changes in the external environment Key Concepts and Statements: Animal form and function are correlated at all levels of organization Feedback control maintains the internal environment in many animals Physical laws also influence animal body plans with regard to maximum size o Need nutrients, pressure on deep sea animals Whether an organism is single-celled or multicellular, all cells must obtain nutrients and get rid of wastes Cells form a functional animal body through their emergent properties o Cells to tissues to organs to organ systems o Differentiation exists An animal’s tissues, organs, and organ systems must act in concert with one another Coordinating activity across an animal’s body requires communication between different locations in the body o Two major systems for this=nervous system and endocrine system An animal achieves homeostasis by maintaining a variable, such as body temperature or solute concentration, at or near a particular value, or set point o Example would be a thermostat o If something goes up, feedback brings it back down The set points and normal ranges for homeostasis can change under various circumstances. In fact, regulated changes in the internal environment are essential to normal body function Questions: What kind of physical laws limit the range of animal forms? o Limit strength, diffusion, movement, size, and heat exchange Tell me about properties of water and body shape in water-dwelling organisms as shown in the next slide. o Seals, penguins, tuna o Fusiform (tapered body form at both ends) is an example of convergent evolution Overcoming the same environmental challenge o Example is when swimmers shave their entire bodies What’s the deal for a single-celled organism? o An amoeba is a single-celled organism o They have sufficient membrane surface area in contact with their environment to carry out all necessary exchange o Mostly aquatic, or they go dormant (during dry times) o Matter of diffusion Oxygen dissolves in water, carbon dioxide dissolves in water What’s the deal for a simple multicellular organism with only two cell layers? o Pond-dwelling Hydra has both layers in direct contact with environment o Its gastrovascular cavity opens to external environment, so both outer and inner layers of cells are constantly bathed by pond water What’s the deal for a complex multicellular organism? o Needs a circulatory system and animal is composed of many cells, each with its own plasma membrane across which exchange must occur o Multicellular organization only works if every cell has access to a suitable aqueous environment, either inside or outside animal’s body o Specialized surfaces that are extensively branched or folded, which increases surface area Internal body fluids link exchange surfaces to body cells. What’s this all about? o Spaces between cells are filled with fluid called interstitial fluid o Also contains circulatory fluid aka blood o Exchange between interstitial fluid and circulatory fluid enables cells throughout the body to obtain nutrients and get rid of wastes What is the hierarchy of organization of body plans? o Cells to tissues, tissues to organs, organs to organ systems o Digestive system, circulatory system, reproductive system, etc. o Bottom up shows emergent properties o Top down shows multilayered basis of specialization What are the four main types of animal tissues? (Just know functions) o Epithelial, connective, muscle, and nervous tissues What are the general functions of epithelial tissue? o Skin and coverings of internal organs o Protection, conservation of water, regulation, diffusion What are the general functions of connective tissue? o Holds everything together o Fibroblasts, macrophages o Tendons, ligaments, bone, blood, adipose tissue, cartilage What are the general functions of muscle tissue? o Movement (voluntary and involuntary) o Skeletal, smooth, cardiac What are the general functions of nervous tissue? o Communication, reaction to stimulus How does this work during long dives by harbor seals? o Collapse their lungs, slows heart rate, lowers body temperature What are the two major systems for controlling and coordinating responses to stimuli? In general, how do they work? o Endocrine and nervous systems o Hormone signals travel everywhere o Neuron signals travel to specific locations and conveys info by particular pathway the signal takes What is a major difference between the endocrine and nervous system? o Endocrine system is better for coordinating gradual changes that affect entire body like growth, development, reproduction, metabolic processes, digestion o Nervous system is well adapted for directing immediate and rapid responses to the environment like reflexes and other rapid movements An animal is said to be a regulator for a particular environmental variable if...what? o They have internal control to maintain internal environment that is different from environment, river otter An animal is said to be a conformer for a particular environmental variable if...what? o They allow the internal conditions to vary with the environment, fish How do some organisms (i.e. spider crab) conform to more constant environments, such as the relatively stable solute concentration (salinity) of the ocean environment? o Spider crabs let their internal solute concentration conform to the relatively stable solute concentration of their ocean environment How can an organism (i.e. bass) be both a regulator and a conformer? Think about internal versus external temperature, and internal versus external solute concentration. o Temperature conformer, but maintaining constant solute concentration o Even though the bass conforms to the temperature of the surrounding water, it regulates the solute concentration in its blood and interstitial fluid What is homeostasis, and what are a couple of examples that we just discussed? What are some examples of homeostasis in humans? o Maintaining internal environment that remains constant o Temperature, blood glucose levels, and endotherms o Salinity What is negative feedback? o Feedback to make something stop (temperature is increasing, so thermostat stops it from continuing) o Blood sugar increases after you eat, signals go to Pancreas, insulin is secreted (beta cells), which then causes the liver and other cells to take up glucose (used for metabolism, or stored as glycogen/starch in liver) What is positive feedback? o Birth example o Nerve impulses go to brain, releases oxytocin, increases contractions, more contractions means fetus pushes harder on cervix, more painful contractions Does positive feedback really maintain homeostasis? o If the stimulus stops, the feedback stops o No, but it eventually comes to an end o Positive feedback is used more to drive processes to completion What are a couple examples of regulated changes in the internal environment? o Puberty and woman’s menstrual cycle What is circadian rhythm? o Sleep cycle o Set of physiological changes that occur roughly every 24 hours o Intrinsic to the body, although the biological clock is normally coordinated with the cycle of light and darkness in the environment o Variation in core body temperature and melatonin concentration in blood What is acclimatization? Tell me about the example of an elk or other mammal moving into mountains from sea level? o Higher atmosphere, less oxygen o Gradual process by which an animal adjusts to changes in its external environment like an elk undergoing kidney function transformation o Acclimatization is a temporary change during an animal’s lifetime, and should not be confused with adaptation, which is the process of change in a population brought about by natural selection acting over many generations How about humans ascending a high peak? o Like climbing Everest, you have to climb a little, then chill at a base. You keep doing that up and up o Adaptation is a species changing genetically o Adjustment that you make in your own body during lifetime in response to environmental condition Sections 45.2 and 45.3 Hormones Vocab: Hormone: chemical compound produced in one part of the body that has an effect on another part of the body Hormone cascade: sets of hormones from hypothalamus, anterior pituitary, and a target endocrine gland are organized into this, essentially it redirects signals from the hypothalamus to other endocrine glands Oxytocin: neurohormone released from posterior pituitary gland and causes mammary glands to secrete milk Negative feedback: response reduces initial stimulus Positive feedback: reinforces a stimulus, leading to an even greater response Hypothalamus: coordination of endocrine signaling region, receives information from nerves throughout the body and in response initiates endocrine signaling appropriate to the environmental conditions Pituitary gland: gland located at the base of the hypothalamus, which receives signals from the hypothalamus, consists of two lobes Posterior pituitary: extension of hypothalamus Anterior pituitary: endocrine gland that synthesizes and secretes hormones in response to hormones from the hypothalamus Antidiuretic hormone (ADH): vasopressin, regulates kidney function, secretion of ADH increases water retention in kidneys and helps maintain normal blood osmolarity Prolactin: secreted by anterior pituitary, stimulates milk production Tropic hormones: anterior pituitary hormones in hormone cascade pathways, FSH/LH Thyroid hormone: regulates bioenergetics, helps maintain normal blood pressure, heart rate, muscle tone, regulates digestive and reproductive functions Thyroid gland: organ in the neck consisting of two lobes on the ventral surface of trachea Growth hormone: GH, secreted by anterior pituitary, stimulates growth through both tropic and nontropic effects Parathyroid glands: set of four small structures embedded in the posterior surface of the thyroid, play major role on blood calcium regulation, if the blood calcium levels fall below a set point, the glands release parathyroid hormone PTH Calcitonin: hormone released if blood calcium levels rise above set point, inhibits bone breakdown and enhances calcium excretion by kidneys Adrenal glands: located atop the kidneys (renal organs) Catecholamines: a class of amine hormones synthesized from the amino acid tyrosine, includes norepinephrine and epinephrine, involved in fight or flight Glucocorticoids: primary effect on glucose metabolism, cortisol, promote glucose synthesis from noncarbohydrate sources, causes breakdown of muscle proteins Mineralocorticoids: mineral metabolism, act in maintaining salt and water balance Androgens: synthesized by testes, includes testosterone, play major role in puberty Estrogens: responsible for maintenance of female reproductive system and development of female secondary sex characteristics Progestins: involved in preparing and maintaining tissues of the uterus required to support the growth and development of an embryo Melatonin: modified amino acid that regulates functions related to light and seasons Pineal gland: small mass of tissue near the center of brain, secretes melatonin Melanocyte-stimulating hormone: MSH, secreted by anterior pituitary, has distinct functions in different evolutionary lineages Key Concepts and Statements: Feedback regulation and coordination with the nervous system are common in endocrine signaling. Diverse functions have evolved for many vertebrate hormones. The hypothalamus plays a central role in integrating the endocrine and nervous systems. Questions: What is the endocrine system and what does it regulate? o Production of hormones o Endocrine glands (ductless) o ‘Damn near everything’ Chart on slide o Hypothalamus Hormones released from posterior pituitary gland (oxytocin and vasopressin) Releasing and inhibiting hormones (regulate anterior pituitary) o Pituitary gland Anterior FSH and LH, TSH, ACTH, Prolactin, GH Posterior Oxytocin, vasopressin (ADH) o Thyroid gland Thyroid hormones stimulate and maintain metabolic processes Calcitonin lowers blood calcium levels o Pancreas Insulin lowers blood glucose level Glucagon raises blood glucose level What is a simple endocrine pathway? What is the negative feedback? Explain slide 12. o Endocrine cells respond directly to an internal or environmental stimulus by secreting a particular hormone o Secretin signaling Low pH in duodenum, S cells of duodenum, secretin, pancreatic cells, bicarbonate release o Hormone affects one area/endocrine gland/organ with endocrine cells directly o Does not involve nervous system What is a simple neuroendocrine pathway? What is positive feedback? Explain slide 14. o Stimulus is received by a sensory neuron which stimulates a neurosecretory cell o Oxytocin signaling Suckling, oxytocin, smooth muscle in mammary glands, milk release Why are insulin and glucagon considered to be an antagonistic hormone pair? o If glucose goes below the normal level, it involves glucagon o Secretion of glucagon by alpha cells of the pancreas, breakdown of glycogen and release of glucose into blood, blood glucose level rises, goes back to normal What do insulin and glucagon regulate? o Blood glucose levels What types of pathways are these? What type of feedback is involved in each? o Simple endocrine How is insulin doing its job of lowering blood glucose levels? o Insulin causes glucose to be pulled out into body cells for metabolism, or to the liver for storage as glycogen What’s the deal with glucose uptake by cells? o Not much stored, except for in the liver What’s the deal with the liver and glycogen in the presence of insulin? o Glycogen is stored in the liver in presence of insulin How is glucagon doing it’s job of raising blood glucose levels? o What’s the deal with the liver and glycogen in the presence of glucagon? o Broken down What causes diabetes mellitus? o Too much glucose in the blood, removed via secretion of insulin (so maybe you’re not making enough insulin and glucose isn’t removed, or What happens with regard to glucose? o What can happen when fat becomes the main substrate for cellular respiration? o Diabetic ketoacidosis, pH goes low What happens in the kidneys? o What kind of disease is type 1 diabetes (insulin- dependent diabetes)? o Autoimmune disease since you’re attacking your own tissues o Insulin producing cells are destroyed What destroys what when you have diabetes type 1? o When does type 1 diabetes usually show up? o As a child What is type 2 diabetes? o Non-insulin dependent diabetes What significantly increases the risk of type 2 diabetes? o When does type 2 diabetes show up? o 40 years or older What exactly is the hypothalamus doing? o Plays a central role in integrating the endocrine and nervous systems Where does the hypothalamus receive hormones from? Where does the hypothalamus send signals to? Is the posterior pituitary and endocrine gland unto itself? Where do posterior pituitary hormones come from? Is the anterior pituitary an endocrine gland unto itself? Where do anterior pituitary hormones come from? Where are the posterior pituitary hormones oxytocin and antidiuretic hormone (ADH) being synthesized? o ADH is synthesized in kidney tubules o Oxytocin is synthesized in mammary glands and uterine muscles Where are the posterior pituitary hormones oxytocin and antidiuretic hormone (ADH) being synthesized? Where are they being stored? How do they get from the hypothalamus to the posterior pituitary? What stimulates their release from the posterior pituitary? What does oxytocin do? o Uterine contractions o One more thing What does ADH do? o Where are the anterior pituitary hormones being synthesized? o Anterior pituitary How is the secretion is the anterior pituitary hormones regulated? What is a hormone cascade in general? o Going from the top of a hormone chain to the bottom o Look at example of the regulation of thyroid hormone secretion What is hypothyroidism? o Low thyroid use → low blood pressure What is hyperthyroidism? o High thyroid use → faster heart rate, higher blood pressure What are thyroid hormones? o What does dietary iodine have to do with anything? What does normal thyroid function lead to in humans and other vertebrates. What are tropic hormones? o What are nontropic hormones? o Why are FSH, LH, TSH, and ACTH tropic hormones? o Why are MSH and prolactin nontropic hormones? o Why is GH both tropic and nontropic? o What’s the deal with the liver and insulin-like growth factors (IGFs)? o Involved mainly with bone and ligament growth What is the result of hypersecretion of GH in humans? o They keep growing for a while to be really tall “gigantism” o Acromegaly What is the result of hypersecretion of GH in humans? o Dwarfism What is the common role of thyroxine across many evolutionary lineages? What is the role of thyroxine in frogs? o Tadpoles to adult frog Tell me about the functions of prolactin o What does it do in mammals? o Milk production What does it do in birds? What does it do in amphibians? Freshwater fishes? What does all of this suggest about prolactin from an evolutionary point of view? What are the diverse functions of melanocyte- stimulating hormone (MSH)? o Memory and suppresses appetite What does it do in amphibians, fishes, and reptiles? What does it do in humans? How might the specialized action of MSH that has evolved in the mammalian brain prove to be of medical importance? What is cachexia? Sections 44.1 and 44.2 Osmoregulation and Excretion Vocab: Key Concepts: Osmoregulation balances the uptake and loss of water and solutes An animal’s nitrogenous wastes reflect its phylogeny and habitat Regulating the chemical composition of body fluids depends on balancing the uptake and loss of water and solutes Maintaining and osmolarity difference between an animal’s body and its external environment carries an energy cost. Because diffusion tends to equalize concentrations in a system, osmoregulators must expend energy to maintain the osmotic gradients that cause water to move in or out The ultimate function of osmoregulation is to control solute concentrations in cells. Most animals do this indirectly by managing the solute content of an internal body fluid that bathes the cells Because most metabolic wastes must be dissolved in water to be excreted from the body, the type and quantity of an animal’s waste products may have a large impact on its water balance. In this regard, some of the most significant waste products are the nitrogenous breakdown products of proteins and nucleic acids In general, the kind of nitrogenous wastes an animal excretes depends on both the species’ evolutionary history (phylogeny) and its habitat, especially the availability of water Questions: If the process of osmoregulation is based largely on the controlled movement of solutes between internal fluids and the external environment, then what’s the deal with water? o What is a hypotonic solution? o Solute inside greater than solute outside o Lysed because water goes in cell What is an isotonic solution? o Solute inside equals solute outside o Normal cell What is a hypertonic solution? o Solute inside is less than solute outside o Shriveled because water goes outside cell What is osmosis? What is osmolarity? If two solutions are separated by a selectively permeable membrane, what are isosmotic, hyperosmotic, and hypoosmotic solutions? What’s going on here? (Slide 12) o There are more solutes on the left side of the selectively permeable beaker o The net water flow goes from right to left o Hyperosmotic side is the one with higher solute concentration and lower free water concentration o Hypoosmotic side has lower solute concentration and higher free water concentration What are two ways that animals can maintain water balance? o They can be either osmoconformers, and osmoregulators What are osmoconformers? What kinds of animals are they? o They go with their environment, so whatever osmolarity of environment is, they have the same o Marine invertebrates What are osmoregulators? What kinds of animals are they? o They regulate their osmolarity o Marine vertebrates and freshwater invertebrates Compared to the osmolarity of the surrounding water, what must the body fluids of most marine animals be? o Hypo-osmotic (lower than outside) What do you see here? (Slide) o Osmoregulatory challenges and mechanisms o Solute inside is lower than outside, so you have relatively higher water inside versus outside o Problem waterwise is that you’re losing water to the outside via o Active transport of ions gets rid of the ions Compared to the osmolarity of the surrounding water, what must the body fluids of freshwater animals be? o Salmon migrate between freshwater and seawater. How do they osmoregulate? What is it called when they adjust to different conditions? o What is anhydrobiosis? What’s the deal with tardigrades? What is trehalose? o Life without water What are some adaptations that reduce water loss for survival on land? Consider body coverings and time of activity o How do animals lose water? o How do animals compensate for lost water? o Explain Slide 37 o How do animals maintain osmotic gradients? o Active transport What does the energy cost of osmoregulation depend on? o Surface area of exchange How do many animals minimize energy costs associated with osmoregulation? o How does controlling solute concentrations in cells work in vertebrates and other animals with closed circulatory systems? o In most animals, what do osmoregulation and metabolic waste disposal rely on? o What are transport epithelia? o How is it possible for the albatross to survive on sea water? o How does the albatross’ ability to use seawater compare with the ability of humans to use seawater? o When nitrogen is removed from proteins and nucleic acids, what form is it in? o What is the problem with ammonia (NH3) and ammonium ions (NH4+)? o Aquatic animals, including most bony fish, excrete ammonia directly. What do other animals do to counter the toxic effects of ammonia and ammonium ions? o How do aquatic organisms deal with ammonia? o They get rid of ammonia ions via water since they live in it Why is ammonia such a problem, especially for terrestrial animals? o It’s very toxic and interferes with oxidative phosphorylation How is urea made? o What are its advantages? o Less toxic o Soluble in water o Excreted in urine What is it’s main disadvantage? How is uric acid excreted? What are the advantages of uric acid as a way of getting rid of nitrogen? What is the main disadvantage? Do humans produce uric acid? What does it cause? What’s the deal with terrestrial turtles versus aquatic turtles? What does the immediate environment of an embryo have to do with the handling of nitrogen? How does the situation for amphibians and mammals differ from that of animals that produce shelled eggs? What is the amount of nitrogenous waste produced by animals linked to? Chapter 42 Circulation and Gas Exchange Vocab: Key Concepts: Circulatory systems link exchange surfaces with cells throughout the body Coordinated cycles of heart contraction drive double circulation in mammals Patterns of blood pressure and flow reflect the structure and arrangement of blood vessels Blood components function in exchange, transport, and defense Gas exchange occurs across specialized respiratory surfaces Breathing ventilates the lungs Adaptations for gas exchange include pigments that bind and transport gases Oxygen and carbon dioxide (and other small nonpolar molecules) can move between cells and their immediate surroundings by diffusion Cholesterol travels in blood plasma mainly in particles that consist of thousands of cholesterol molecules and other lipids bound to a protein Questions: Why are gas exchange and circulation linked in multicellular organisms? What’s the deal for a unicellular organism? What’s going on with this axolotl? What are the limits of diffusion? How long does it take for a substance to diffuse from one point to another? Why does this put a substantial constraint on the body plan of an animal? Natural selection has resulted in two general solutions to this problem.
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