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Final Study Guide

by: Carter Buuck

Final Study Guide Biology 211

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Carter Buuck
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Covers what is on the final. Very few sections not fully completed because they are better understood by diagrams in the book (gills), or are too vast to cover in one study guide (mammals).
Principles of Biology
Dr. Gregor Yanega
Study Guide
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This 24 page Study Guide was uploaded by Carter Buuck on Friday May 20, 2016. The Study Guide belongs to Biology 211 at Linfield College taught by Dr. Gregor Yanega in Spring 2016. Since its upload, it has received 51 views. For similar materials see Principles of Biology in Biology at Linfield College.

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Date Created: 05/20/16
 QUESTIONS FROM UNIT 3: ANIMALIA  I call your attention to the fact that this is not a “study guide” in any literal sense. No false expectations! These questions are ways of checking your progress and making sure you’re on the right track thematically. After reading this set of questions you may ask yourself: Have I studied the Ecdysozoans enough? Do I know which lineage within the Ecdysozoa has participated in a mutualism that led to the coevolution and concurrent diversification of both the Anthophyta and this clade? If your answer is no, your path is clear.  I have mentioned this in class, but I am going to say it again here. I recommend that you do four things when studying.  Identify the major, process-oriented areas of physiology and organismal biology that we have discussed in this section. (Examples: How do muscles work? How do nervous systems work? How does respiration and circulation work? What are the key characteristics of animal development, and possibly, reproductive modes or strategies of the various phyla?)  Broad evolutionary pattern. Examine the synapomorphies that unite clades both at the level of the phyla and “super phyla” but also ALL THE OTHER CLADES we talked about. A few notes about this section: I don’t need you to know what level of organization “gnathostomes” represents, but, you do need to know what gnathostomes are and which taxa are united under this synapomorphy. Also, you do need to know the phyla and classes we have discussed. You should know that the Lophotrochozoa includes the Mollusca, Platyhelminthes, Rotifers, Annelida, and so on. In short you should know the relationships among taxa in the animal phylogeny we gave you. Don’t spend all your time memorizing this, but practice it.  Clade specific details. You should have a “file” or study section available on each one of the clades (e.g., Class Mammalia) that we’ve read about or discussed in class. Some of these clades (e.g., tetrapods) will include many more details than others (Rotifers). Many of these traits will overlap with things you are studying in (2). Be sure you can recognize them on sight, and can recognize key morphological features.  Make connections among topics studied. For example, if you are studying characteristics of embryological development, be sure to note the differences between the deuterostomes (mouth forms second; a characteristic of chordates+ echinoderms) and protostomes (mouth forms first, cell cleavage is determinate, features spiral orientation of cells in morula stage). This process of connecting knowledge from one part of the course to another is vital, and something you should think about and practice as you become more familiar with the material.  Here are some questions to think about.  Tissue/germ layers are one of the key features that separate basal animal clades.  How does the embryo form? What are the various stages of development? How do deuterostomes differ from protostomes, and which lineages are associated with each? a. Pg 668 b. The zygote of an animal undergoes a series of meiotic cell divisions without cell growth known as cleavage c. An eight-cell embryo is formed by three rounds of cell division d. In most animals, cleavage produces a multicellular stage called a blastula. i. The blastula is typically a hollow ball of cells that surround a cavity called the blastocoel e. Most animals also undergo gastrulation, a process in which one end of the embryo folds inward, expands, and eventually fills the blastocoel, producing layers of embryonic tissue i. The ectoderm (outer layer) ii. Endoderm (inner layer) f. The pouch formed by gastrulation, called archenteron, opens to the outside via a blastopore g. The endoderm of the archenteron develops into the lining of the animal’s digestive tract h. Stages i. Zygote ii. Eight-cell stage iii. Blastula iv. Gastrulation i. Deuterostomes i. Echinoderms and chordates ii. Cleavage 1. Characterized by radial, indeterminate iii. Coelom formation 1. Begins in gastrula stage 2. Forms from the mesodermal outpocketings of the archenteron iv. Blastopore 1. Anus develops from the blastopore 2. Mouth forms from a secondary opening j. Protostomes i. Molluscs and annelids ii. Cleavage 1. Spiral, determinate cleavage iii. Coelom formation 1. Coelom forms from splits in the mesoderm iv. Blastopore 1. Mouth develops from blastopore  Chordates and development. What are the characteristics of the chordates (four)? What is a nodochord? How is it like a skeleton? What are HOX genes (and/or homeobox genes)? Why are they important, along with gene duplication events (and whole genome duplication events) in spurring morphological and genetic variation? What does Sonic Hedgehog gene do, and how does these kinds of genes interact with other genes? a. Synapomorphies i. Notochord 1. Longitudinal flexible rod located between the digestive tube and the nerve cord 2. Provides skeletal support and aids in swimming 3. In vertebrates, a jointed skeleton from around notochord 4. Forms discs in humans ii. Dorsal hollow nerve tube 1. Located dorsal to notochord 2. Develops into CNS, brain, and spinal cord 3. Develops from ectodermal tissue a. First arises in cnidarians iii. Pharyngeal clefts 1. Slits that arise near pharynx 2. Not gills, but give rise to them 3. Feeding structures originally, but then take on new functions 4. In tetrapods, form parts of ear, head, and neck structure iv. Muscular post anus tail 1. Lost in many species during embryonic development 2. Contains skeletal elements and muscle (in vertebrates) 3. Used for locomotion in aquatics b. HOX Genes i. a class of genes that determines the basic structure and orientation of an organism ii. Head to tail patterning iii. Essential for segmentation iv. Found in same part of genome v. Order of the Hox genes corresponds to the body orientation 1. When a change in the body occurs a change in that same spot of the Hox gene can be seen vi. Control development of major regions of the vertebrate brain vii. Responsible for genome and body variation viii. Trend: Increasing body plan complexity over time ix. Trend: Increases in the number of HOX gene clusters through time 1. As HOX gene increases, so does the body development c. Sonic Hedgehog Gene i. Responsible for causing polydactyly ii. Does so by sending out a signal to the developing hand iii. Certain digits develop as a response to the strength of the sonic hedgehog gene they receive iv. If a sonic hedgehog gene is stronger than normal, it will cause for six digits to develop instead of the normal five. v. Similar to Hox gene 1. When manipulated (loss or duplication) results in diversification or loss  What kinds of function are associated with each tissue layer? 674 Which tissue layer gives rise to most of the nervous system and brain? Which layer gives rise to muscle and bone? a. Ectoderm i. Germ layer covering the surface of the embryo ii. Gives rise to the outer covering of the animal and, in some phyla, the CNS iii. Neural tissue b. Endoderm i. Innermost germ layer ii. Lines the pouch that forms during gastrulation and gives rise to the lining of the digestive tract and organs (liver and lungs) 1. The gut c. Mesoderm i. In all bilaterally symmetrical animals (Triploblastic) ii. Fills much of the space between the ectoderm and endoderm iii. Forms the muscles and most other organs in the digestive tract and the outer covering of the animal iv. Skeletal system v. Muscle system  Circulation/Respiration. What is the difference between an open and closed circulatory system? What is the relationship between respiration and circulation? How do hearts differ from worms to bats? What trends do we see in size, compartmentalization, and what is the main purpose of a circulation system? Specifically, what are the constraints imposed upon highly aerobic, homeothermic, and mobile organisms by circulation and respiration? What respiratory structures do arthropods use to take in oxygen or release carbon dioxide? Why is the avian system of respiration unique? a. PG 924 b. Open vs closed system (Figure 42.3) i. Most animals have an open circulatory system ii. Both have 3 components 1. Circulatory fluid (blood or hemolymph) 2. Set of tubes (vessels) 3. Muscular pump (in the heart) iii. Open system 1. In arthropods and most mollusks, fluid bathes the organ directly 2. Hemolymph a. No distinction between blood and interstitial fluid iv. Closed system 1. Blood in confined to vessels and is distinct from interstitial fluid 2. More efficient at transporting circulatory fluids a. High pressure where blood is pumped out 3. ALLOWS FOR MORE GROWTH 4. PRESSURE DRIVES THE RETURN OF BLOOD TO HEART a. HIGH PRESSURE IN ARTERIES b. LOW PRESSURE IN VEINS c. Relationship between respiration and circulation i. Pulmocutaneous circuit in amphibians? ii. ALL TISSUES NEED OXYGEN TO SURVIVE 1. HAS TO BE SOMEWAY OF GETTING OXYGEN INTO TISSUES iii. THE BIGGER THE ORGANISM THE MORE EFFICIENT THE CIRCULATION SYSTEM NEEDS TO BE 1. CIRCULATION ARISES FROM RESPIRATION 2. A LARGER ORGANISM WILL HAVE CLOSED SYSTEM iv. AT ANY JUNCTION WHERE BLOOD AND OXYGEN COME INTO CONTACT MUST BE A MOIST SURFACE d. Single circulation (FIG 42.4) i. Petromyzondita through actinistia ii. Single circulation with a two chambered heart 1. Blood leaving the heart passes through 2 capillary beds before returning to the heart e. Double circulation i. Extant tetrapods 1. 3-4 chambered heart 2. Blood passes through a single capillary bed before returning to the heart 3. Maintains a higher blood pressure 4. Pulmonary (Reptiles/mammals) or pulmocutaneous circuit (amphibians) f. Avian respiration i. One way flow of air 1. Bellows (air sacs) able to draw loads of air in and force air out across the lungs 2. Fill up air sacs, push across lungs, lungs take out maximum amount of oxygen 3. Allows for highly efficient 4. Mammals only have a certain tidal volume and so they are less efficient a. Make up for this by maximum surface inside of lung 5. Power flight is extremely costly a. Hearts are larger b. Cardiovascular system needs to be stronger  Muscle physiology. What roles do actin and myosin play in muscle fibers? How does a nervous impulse enervate (or stimulate) a muscle cell via a motor neuron? What chemicals are present? What role do t- tubules play? What moves the myosin heads into their ready position? What is a cross-linkage? What is the Z-line? What is a sarcomere? Are muscle bundles bigger or smaller than muscle fibers? Where do you find smooth muscle? a. Actin (thin) and myosin (thick) are responsible for the contraction of a muscle i. Myosin heads pull actin (and Z-lines) closer to one another 1. Myosin heads interact with ATP to bind to actin and form a cross bridge a. Calcium ions cause for tropomyosin bound along the actin strands to shift positions and expose the myosin binding sites on the actin 2. Performs a power stroke that pulls the actin filaments closer to one another and then it breaks the cross bridge b. A nervous impulse is sent down the axon of a neuron to the synaptic terminal i. The synaptic terminal works with the skeletal muscle to transfer the nervous impulse to the muscle to generate a response 1. Acteylcholine (Ach) released at the synaptic terminal diffuses across synaptic cleft and binds to receptor proteins on muscle fiber’s plasma membrane, triggering an action potential 2. Action potential is sent along the plasma membrane down T-Tubules a. Allow depolarization of the membrane to  quickly penetrate to the interior of the cell. 3. This action potential triggers calcium ion release from  sarcoplasmic reticulum  4. Calcium binds to troponin and reveals myosin binding site 5. Myosin binds and muscle contract c. Sarcomere i. The basic contractile unit of skeletal muscle ii. Consists of actin (thin), myosin (thick),  iii. Thin filaments attach at Z­line iv. M line is overlap between actin and myosin d. Skeletal muscle order i. Bundle ii. Single muscle fiber iii. Myofibril iv. Sarcomere e. Smooth muscle is found in walls of hollow organs like blood vessels and  organs of the digestive tract  Neural physiology. How does an action potential work? At resting potential, where is potassium most concentrated? What does threshold represent? How does the refractory period work and why is it important? What is the difference between a squid axon and a donkey axon in terms of rate of signal transmission? What does salutatory movement mean? What chemical stimulates the release of neurotransmittersx from a synapse? What kinds of proteins receive neurotransmitters? a. Action potential i. Stimulus enters the dendrites ii. Moves into the soma 1. Sodium potassium pump maintains negative charge inside membrane 2. Requires ATP 3. Very few passive sodium channel a. Very hard for potassium to get back in 4. Many passive sodium channels a. Allow for sodium to leave cell b. Maintains negative charge 5. All of these factors help establish resting potential iii. Opening of some voltage gated sodium channels creates a slightly more positive charge on the inside 1. Once a certain positivity is reached, all voltage gated sodium channels open and depolarize the cell 2. Sends signal down entire membrane to create a positive charge on the inside (moves down the line) 3. Myelin sheath cause for a jumping of the signal between Schwann cells a. Salutatory movement i. Allows for a faster movement of the signal ii. Less ions are lost along the channel iv. Refractory period 1. Driven by the opening of voltage gated potassium channels 2. Repolarization v. Signal reaches synaptic terminal 1. Calcium causes the release of Ach 2. Binds to ligand-gated Na channels on other dendrites vi. Caused by a depolarization sufficiently shifting the membrane potential, resulting a massive change in membrane voltage vii. Arise through voltage gated ion channels opening or closing when the membrane potential passes a particular level b. Resting potential i. High potassium concentration inside the cell, high sodium concentration inside the cell ii. -70 mV c. Threshold i. The potential that an excitable cell membrane must reach for an action potential to be initiated ii. About -55 mV d. Refractory period (Fig 48.11) i. The short time immediately after an action potential in which the neuron cannot respond to another stimulus, owing to the inactivation of voltage gated sodium channels ii. The “downtime” when a second second action potential cannot be initiated iii. Due to the inactivation of sodium channels, not a change in the ion gradients across the plasma membrane iv. Limits the maximum frequency at which action potential can be generated v. Ensures that all signals in an axon travel in one direction, from the cell body to the axon terminals vi. The sodium channels close, but some potassium channels are still open 1. As these potassium channels close and the sodium channels become unblocked (though still closed), the membrane returns to its resting state e. Rate of signal transmission i. Rate of signal transmission in mammals, reptiles, and fish is faster because it can have a smaller, more efficient axon because it is myelinated and salutatory movement occurs f. Elevated calcium ion concentration causes synaptic vessels to bind to the synaptic cleft membrane and release the neurotransmitter into the synaptic cleft i. Neurotransmitters bind to ligand-gated ion channels in the postsynaptic membrane ii. This binding can open the channel and allow for the movement of sodium and potassium  What are some characteristics of Tiktaalik that indicate that it is intermediate between tetrapod fishes and amphibians? When did Tiktaalik live? a. Had fins that were strong enough to lift itself out of water i. These modified fins would become the limbs of all mammals ii. Also possessed a unique bone structure that had a large surface that allows for muscle attachment between the shoulder and the underside of the upper arm, iii. It has a movable elbow and wrist that is flexible to a point where the “palm” of the animal can touch the ground. iv. FREEDOM OF THE HEAD JOINT v. SHOWED TRAITS THAT ALLOW THEM TO LIVE IN TWO DIFFERENT ENVIRONMENTS 1. FINS AND TAIL 2. FUNCTIONAL LUNGS 3. EVOLUTION IS NOT LINEAR a. MANY TRNASITIONAL FORMS THAT ARE SUCCESSFUL AND FAILURES vi. The discovery of Tiktaalik bridged the gap between fish and Icthyostega as well as providing a very important piece of evolutionary history. vii. Existed about 365 million years ago  What are some other examples of gradualism in transitional trait evolution (or, the “mosaic of trait evolution”)? Think about phenotypic plasticity in lungfish that can walk on land; think about dinosaurs that had feathers but didn’t and couldn’t fly; think about platypus that lay eggs, have fur, and produce milk but lack nipples. Platypus also have reptilian/bird sex chromosomes. You can no doubt think of others! For example, Choanoflagellates!  Why are Choanoflagellates and Poriferans similar? How are they different? What is an amoebocyte? What is a choanocyte? What is a spicule? In which way are Tunicates like Porifera? a. They are similar because they are the only two species that lack true tissues (endo, ecto, meso) in the animal kingdom i. They are different because they Porifera are chemoheterotrophic by digestion and embryonic development ii. Porifera also contain spicules 1. Sharp structural elements that provide support and fend off predators b. Amoebocyte i. An amoeba-like cell that moves by pseudopodia and is found in most animals ii. Transport nutrients to other cells of the sponge body and produce materials for skeletal fibers (spicules) iii. MAKE UP SPICULES iv. PLURIPOTENT AND CAN REFORM SPONGE IN DAMAGED v. Capable of becoming other types of sponge cells 1. Gives sponge body remarkable flexibility, allowing it to adjust its shape as a response to changes in physical environment c. Choanocyte i. Flagellated cells that line the spongocoel 1. The cavity inside the sponge ii. “Collar cells” iii. Beating flagella create a current that draws water in through the pores and out through the osculum d. Tunicates and Porifera i. Tunicates (Urochordata) are the chordate version of Porifera ii. They have developed suspension feeding and are the only chordates to do so 1. Similar feeding methods that involve the intake of water and nutrients through pores  When did Homo and Pan diverge from one another? a. 6-7 million years ago  Early life. What is the Cambrian Explosion and why is it important? What kind of life was present prior to the Cambrian? When did the first animals arise? How did the Rangeomorphs like Charnia differ fundamentally from the animals that came after? What factors may have contributed to the rise of animals in this period and their diversification? For example, what role might predation have played in driving selection for new forms, new defenses, new behaviors? a. The Cambrian explosion was an explosion of life that happened around 530 million years ago b. It helped create an abundance and diversification of life i. Gave rise to arthropods, chordates, and echinoderms ii. An increase in size is seen iii. Minerals and ions in the water were used to form protective shells, bones, and teeth c. Before this event, life was fairly simple and consisted of only a few animal phyla that were small in size i. Sponges d. First animals arose around 700 million years ago e. Charnia i. Might be the earliest life form evidence of animals ii. Lived too deep for photosynthesis so fed by intaking nutrients in the water 1. Lacked any form of development that current animals have, but do seem to be chemoheterotrophs f. Causes of diversification and abundance i. An increase in oxygen allowed for life to grow larger and more complex 1. Abundance of oxygen in the environment allows for growth because the organism can expand without fear of their tissues being starved of oxygen 2. Debated because if this is the case then why was there not a diversification of life when the oxygen revolution took place almost 2 billion years ago? ii. erosion of rocks in the ocean lead to the release of minerals like calcium, magnesium, and silicon dioxide into the water 1. The abundance of these minerals and ions in the water allowed for organisms to become more complex and develop by making forming shells, bones, and teeth g. Predation was new to the Cambrian explosion and drives evolution because the predator and the prey must constantly adapt in order to either capture the prey or avoid the predator i. This ongoing circle of evolution helps create advantageous traits that allow for survival and create new organisms  How do organisms maximize their surface area? Why is this important? Give an example. a. Amount of metabolic activity an organism can carry out is proportional to its mass or volume i. Maximizing metabolic rate requires the efficient uptake of energy and raw materials (oxygen and nutrients) as well as effective disposal by waste ii. This ability decreases as an organism grows larger due to having more volume and the same amount of surface area b. Flattening i. A very thin organism like the flatworm can use its whole body surface for gas exchange c. Branching i. Branched filaments of mycelium increase surface area across which water and minerals can be absorbed from the environment d. An organism can make itself extremely small through folding or flattening e. This gives it maximum surface area that allows for rapid gas exchange i. Leaves ii. Platyhelminthes (flatworm)  What is a cnidocyte? How do nematocysts work? What is the difference between a polyp and a medusa? To which phyla do they belong? How do most member of this clade reproduce? a. Jellyfish, coral, sea anemonie b. Cnidocyte i. A specialized cell unique to the phylum Cnidaria ii. Contains a capsule like organelle housing a coiled thread that, when discharged, explodes outward and functions in prey capture and defense c. Nematocysts i. In a cnidocyte of a cnidarian 1. Specialized cnidocyte ii. A capsule-like organelle containing a coiled thread that when discharged can penetrate the body wall of the prey iii. When a “trigger” is stimulated by touch or by certain chemicals, the thread shoots out, puncturing and injecting poison into prey d. Polyp i. Cylindrical forms that adhere to the substrate by the end of the body opposite of the mouth and extend their tentacles, waiting for prey ii. Hydras and sea anemones iii. Can slowly move by using muscles at the aboral end of body iv. Both forms are cnidarians e. Medusa i. Flattened, mouth down version of a polyp ii. Moves freely in the water by a combination of drifting and contractions of the body iii. Jellyfish iv. Tentacles of the jelly dangle down from the oral surface, which points downward f. Cnidarian reproduction (Fig 33.8) i. A colony of interconnected polyps results from asexual reproduction by budding ii. Some of these polyps are equipped with tentacles are specialized for feeding 1. Others, specialized for reproduction, lack tentacles and produce tiny medusa by asexual budding 2. Medusae swim off, grow, and reproduce sexually 3. They create a zygote that develops into a solid ciliated larva called a planula 4. Planula eventually settles and develops into a new polyp that will form a colony and restart the cycle  What’s amazing about Tardigrades? What are extremophiles? Examples. a. Can undergo anhydrobiosis i. Evacuate all water inside of body and reduce metabolic rates to zero ii. Allows them to survive extremely difficult environments and even mass extinction 1. Can survive in space and extremely hot and cold temperature iii. Allows for low competition because they can occupy environments nothing else can b. Extremophiles i. An organism that lives in extreme environmental conditions that few other species can survive in 1. Includes organisms that are salt lovers and heat lovers 2. Loricifera  How many different clades of animal have a worm-like appearance? In which ways are these groups similar (yes, I know, they look like worms…)? How are they different? a. ANNELIDIA i. CLOSED CIRCULATORY SYSTEM ii. SEGMENTED iii. AQUATIC b. NEMATODA i. ECDYSIS ii. DECOMPOSERS c. PLATYHELMINTHES i. CAN BE PARASITIC OR NOT d. HEMICHORDATA i. ACORN WORM ii. SOMOCHORD iii. RESEMBLANCE OF GILL SLITS e. DIFFERENT FORMS OF WORM AROSE BECAUSE THEY ARE THE SIMPLEST BODY FORM AND ARE THE MINIMAL AMOUNT OF STRUCTURE AN ANIMAL NEEDS i. JUST A GUT SURROUNDED BY TISSUE  Rotifers! What are they? What features do they have that are important? a. Tiny animals that inhibit freshwater, marine, and damp soil habitats b. Smaller than protists but nevertheless are multicellular and have specialized organ systems c. Alimentary canal i. A digestive tube with two openings, a mouth and an anus 1. As opposed to the gastrovascular cavity of flatworms ii. A pseudocoelomate 1. Fluid in the pseudocoelom serves as a hydrostatic skeleton iii. Crown of cilia that draws a vortex of water into the mouth iv. Posterior to the mouth, have jaws that grind up food v. Parthenogenesis 1. Asexual reproduction in which only of females that produce more females from unfertilized eggs 2. Can produce sexually under high crowding  Echinodermata. What is a water vascular system? How do tube feet work? How do sea stars consume their prey? What are echinoderms considered bilaterians if they are pentaradial as adults? a. Include the seastars and seaurchin b. Synapomorphies i. Deuterostomic development 1. Anus forms first 2. Radial and indeterminate eight cell stage 3. Water vascular system c. Water vascular system i. A network of hydraulic canals branching into extensions called tube feet that function in locomotion and feeding ii. Each tube foot consists of bulb-like ampulla and a podium (foot portion) iii. When the ampullas squeezes, water is forced into the podium, which expands and contracts the substrate iv. Adhesive chemicals are then secreted from the base of the podium, attaching it to the substrate v. To detach the tube foot, de-adhesive chemicals are secreted and muscles in the podium contract, forcing water back into the ampulla and shortening the podium vi. As it moves, a sea star leaves an observable “footprint” of adhesive material of the substrate d. How do sea stars consume their prey i. Use tube feet to grasp prey ii. The arms of the sea star embrace the closed bivalve, clinging tightly with their tube feet iii. Sea star then turns its stomach inside out, everting it through its mouth and into the narrow opening between the halves of the bilvalves shell iv. The digestive system of the sea star secretes juices that begin digesting the mollusk within its own shell v. The sea star brings its stomach back inside its body where digestion of the mollusc’s body is completed 1. The ability to begin digestion outside the body allows the sea star to consume species larger than itself e. Why are they considered bilaterians i. Larvae have a bilateral symmetry ii. Adult forms are not truly radial because the opening of a sea star’s water vascular system is slightly shifted to one side  Extinctions. There are at least three major extinction events you should know. The Devonian extinction (374 mya) killed 80% of marine life. The Permian extinction (250 mya) is thought to have killed 90- 95% of all multicellular life on Earth. And the cretaceous/tertiary extinction (the K/T) killed 60% of all life at 65 million years ago. The K/T extinction is the last great extinction that finished off the large non- avian dinosaur and set the stage for diversification of mammals, arthropods, birds, and plants. Ask yourself: what effect have extinctions had on the diversity of animal life?  Mollusca. There are so many kinds of Molluscs! Name the basic anatomical features of the mollusk. Compare and contrast cephalopods, brachiopods, and gastropods. Contrast cephalopods with other mollusks, compare them to other intelligent, aerobic, animal life. a. Snails, slugs, oysters, clams, octupuses, and squids b. Foot i. Used for locomotion c. Visceral mass i. Contains internal organs d. Mantle i. Tissue covering visceral mass ii. Secretes calcium carbonate to make shell iii. Can extend beyond the visceral mass 1. Producing the mantle cavity a. Which houses the gills, anus, and excretory pores e. Also can use a radula to scrape up food f. Brachiopods i. Superficially resemble clams and other molluscs, but the two halves of the brachiopod shell are dorsal and ventral rather than lateral ii. Attached to seafloor by stock iii. Open shells slightly to allow water to flow through the lophophore g. Gastropods i. Majority of molluscs ii. Marine and freshwater, but forms like slugs and snails have adapted to land iii. Move by a rippling motion of their foot or by means of cilia 1. Explains slow pace iv. Single, spiraled shell for protection and for prevention of dehydration v. Radula can graze on plants, but some have their radula modified for boring holes in the shells of other molluscs or for tearing apart prey vi. Most have head with eyes at the tips of tentacles vii. Terrestrial snails lack lungs and have gas exchange in the skin h. Cephalopods i. Squids, octopuses, and nautiluses ii. Predators that use tentacles to grasp prey 1. Which they bite with beak-like jaws and immobilize with a poison present in their saliva iii. CLOSED CIRCULATORY SYSTEM iv. HAVE A CAMERA EYE v. The foot of the cephalopod has been modified into a muscular excurrent siphon and parts of the tentacles vi. Dart about by drawing water into the mantle cavity and then firing a jet of water through the excurrent siphon vii. The mantle covers the visceral mass of cephalopods, but the shel is greatly reduced and internal or missing altogether viii. Only mollusk with a closed circulatory system ix. They have a well-developed sense organs and a complex brains 1. Ability to learn and behave in a complex manner is essential for these quick moving organisms, unlike their slow relatives  Ecydysozoans! Nematoda. Why are these things Ecdysozoans? Where do you find them? What role do they play in the environment? Which arthropod lineage was likely the first on land? What mutualism, or coevolutionary process is largely responsible for a significant portion of the diversification of the insects? Which insect is the most abundant? How do humans depend on insect life? In which ways are insects vectors of disease? What is a myriapod? a. Ecdysozoans i. Well-developed sensory organs (eyes, olfaction, antennae (touch & smell) ii. Exoskeleton is made of cuticle (layers of polysaccharide) and chitin, for protection and muscle attachment iii. Must undergo ecydysis, the molting of exoskeleton at various larval stages in order to grow iv. Open circulatory system (hemolymph is pumped by heart through arteries and then into sinuses surrounding other tissues and organs, not the same as in verts) v. Various specialized gas exchange mechanisms exist: aquatic species typically have feathery gills; terrestrial arthopods have internal surfaces specialized for gas exchange, like the spiracles of insects (including a developed tracheal system) b. Lophotrochozoa i. Can either be in two larval forms 1. Lophophore a. A crown of ciliated tentacles that function in feeding b. Ectoprocts 2. Trochophore a. Figure 32.12 b. Molluscs and annelids c. A type of free swimming planktonic larva with several bands of cilia c. Nematodes i. Roundworms ii. Found in most aquatic habitats, in the soil, in the moist tissues of plants, and in the body fluids and tissues of animals iii. Body is covered in a tough cuticle (a type of exoskeleton) that is sheds and will secrete a new one iv. Contain an alimentary canal, but lack a circulatory system v. Nutrients are transported through the body via a pseudocoelom vi. Parasites to plants and inside of humans d. Their role in the environment i. Decompose organic matter on the bottom of lakes and oceans ii. Play an important role in decomposition and nutrient cycling e. Arthropods i. Segmented bodies, jointed apendages f. The mutualism of pollination led to a radiation and the evolution of both insects and angiosperms i. Organism receives pollen and nectar, plants get fertilized g. Beatle is the most abundant insect h. The first arthropod on land (about 450 million years ago) was most likely a myriapod, an early ancestor of centipedes and millipedes i. Importance of insects to humans i. Pollination ii. Silk iii. Honey iv. Primary and secondary decomposers that break down waste v. Food source for larger organisms j. Insects as vectors for disease i. Mosquitoes cause malaria ii. Assassin bug causes Chagas disease  What are the relative advantages of exoskeletons and endoskeletons? Why are skeletons important? a. Developed during Cambrian explosion b. Body plan in arthropods did not arise from the acquisition of new Hox genes i. Instead, the evolution of the body segment diversity in arthropods was probably driven by changes in the sequence or regulation of existing Hox genes c. Exoskeletons i. Provide protection ii. Form body shape iii. Prevent dehydration d. Endoskeletons i. Lighter and can support greater weight ii. Allows for larger growth iii. Allows for muscle attachment e. Importance of the skeleton i. The skeleton is necessary to provide the body with shape, structure and support. ii. It also serves to protect the internal structures of the body  Fish! Chondrichythes (sharks, skates, rays) have true jaws and paired fins. They currently lack endochondral bone and are only cartilaginous vertebrates. Describe how countercurrent works in relation to fish and shark gills. Why do sharks sink and fish float? How is tail morphology associated with buoyancy? What are two modes of locomotion found in sharks, skates, and rays? What kind of fish is an Actinistian? How do surviving (extant) Actinistia differ from ancestral species? What are some characteristics of the Actinopterygii? How does suction feeding work? Who are the Myxini and Petromyzontidae? How are they related to the rest of the fishes, vertebrates, and chordates? a. COUNTERCURRENT i. FOUND IN GILLS ii. TWO SETS OF PIPES iii. MAXIMIZES THE OXYGEN IN WATER iv. HIGH OXYGEN AND LOW OXYGEN PIPES RUN IN SEPARATE DIRECTIONS v. EXCHANGE OCCURS BETWEEN THE TWO AND CREATES AN EVEN BALANCE OF THE TWO SUBSTANCES 1. OXYGEN BALANCE 2. BLOOD TEMERATURE  Senses! Be able to describe how hearing works; how the lateral line in fish detects pressure differences in the environment; and broadly recall the variety of sensory inputs animals can detect. a. Hearing i. Vibration sent into ear ii. Passes into auditory canal 1. Skin of inner ear is linked to the three bones a. Incus b. Malleus c. Stapes 2. Oval window a. Carries into cochlea 3. Semi circular canal a. Needed for balance b. Have copula cells c. Wiggle back in forth and detect vibration 4. Basilar membrane a. Has different hair cells b. When fluid goes over these cells they trigger an action potential i. Graded responses similar to muscle ii. Hearing loss is related to loss of hair cells to detect vibrations 1. Reduces gradiation of what you can hear c. This signal is sent from the basilar membrane to the auditory neuron and that signal is sent to the brain  What’s a tunicate?  Amniotes. Mammals and reptiles. Incredibly diverse. Mammals didn’t really diversify until after the K/T extinction, though things like Platypus (monotremata) have been around for more than 100 million years, and early mammals are probably over 165 million years old. Birds are dinosaurs. Dinosaurs have been incredibly diverse. Both rely on features of the amniote egg for their success in conquering a variety of habitats on Earth, and both feature some warm-blooded members (all mammals are warm-blooded=homeothermy).  WHAT ARE LARVAL FORMS FOR AND WHO HAS THEM  SPONGES VS CNIDARIANS VS EVERYTHING ELSE FOR GERM LAYERS  DIFFERENT STAGES OF GASTRULATION  TYPES OF CONNECTIVE TISSUE  LABEL FEATURES OF AMNIOTIC EGG  DINOSAURS a. MEMBERS WHO CAN FLY AND SWIM b. TETRAPODS c. HOMEOTHERMIC MEMBERS (MAY ALL BE) d. LARGEST EVER TERRESTRIAL TETRAPODS e. EXTENT MEMBERS OF BIRDS i. FEATHERED ii. ENDOTHERMIC iii. THEREFORE HAVE HIGH METABOLIC RATES iv. HIGH FUNCTIONING CIRCULATORY AND RESPIRATORY SYSTEMS v. HOW EVOLUTION OF FEATHERS AROS 1. PROCEED FLIGHT IN TERMS OF FUNCTION 2. HAD FEATHERS LONG IN ADVANCE BEFORE FLIGHT 3. THROUGH SOME SORT OF GRADULISM THE USE OF THOSE THERMOREGULATORY STRUCTURES THAT GAVE RISE TO LEAVING THE GROUND A LITTLE BIT EVENTUALLY LED TO FLIGHT a. WING ASSISTED INCLINED RUNNING b. ADVANTAGE OF ESCAPING PREY c. LED TO THE DEVELOPMENT OF MUSCLE AND FEATHER MODIFICATION vi. COMMON ENVIRONMENTAL FACTORS LED TO SIMILAR TRAIS  SPECIFIC CLASSES OF ECDYSOZOA  CONNECTIVE TISSUE  MUSCLE TISSUES a. TENDON CONNECTS MUSCLE TO BONE  NEURAL TISSUES a. GLIAL CELLS i. SUPPORT, REGULATE, AND AUGMENT THE FUNCTIONS OF NEURONS  NEGATIVE PRESSURE IN ANIMALS a. SUCTION FEEDING BY OSTEICTHEYES b. NEGATIVE PRESSURE IN THE LUNGS CREATED BY DOWANWARD MOVEMENT OF DIAPHRAGM AND ALLOWS FOR INTAKE OF AIR c. CIRCULATORY SYSTEM  CHOANOFLAGELETTES a. UNICELLULAR b. COLONIAL  INCOMPLETE METAMORPHASIS a. JUST SMALLER VERSION OF ADULT FORM  COMPLETE METAMORPHASIS a. DIFFERENCE IN APPEARANCE BETWEEN ADULT AND LARVAE STAGE b. AMPIBIANS ARE ONLY VERTEBRA THAT UNDERGO THIS c. LARVAL FORMS ARE BENEFICIAL BECAUSE THEY DON’T COMPETE FOR THE SAME RESOURCES THAT THE ADULTS DO  ACTION POTENTIAL GRAPH  Can’t synthesize all of amino acids in body so we must take certain ones in through food


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