General Biology Exam 4 Study Question Answers

General Biology Exam 4 Study Question Answers – Brandon Skenandore

11/4/11 – Dinosaurs and Birds


What are the differences between vertebrates, tetrapods, and amniotes?

Vertebrates have vertebrae, tetrapods are vertebrate animals with four limbs, and amniotes are animals with a terrestrially adapted amnionic egg.

What are the different Dinosaur lineages and which is the most diverse?

Archosaurs are all dinosaurs. The different lineages are pterosaurs (distinct from birds, dinosaurs), ornithischians, saurischians, and birds. Birds are most diverse

What are the three bones called in the hip?

illium ischium, pubis

What is the difference between the Saurischian hip and the Ornithischian hip?

Saurischian hip is jointed, ornithiscian is the “neater” looking one.

Which of these two is referred to as the “lizard hip” and “bird hip”? Which is the ancestor of birds?

Saurischian – lizard hip. Ornithiscian – bird hip.

What classifies Saurischians? What are Sauropods and Theropods?

Saurischians have a lizard-shaped hip. Sauropods are large, column-footed animals, theropods are the meat-eating dinosaurs, some had feathers.

What classifies Ornithischians? What are the four examples of dinosaurs (the names)?

Ornithischians have a bird-hip. Stegosaurs, ceratopsians, ankylosaurs, and hadrosaurs are examples of dinosaurs.

When was it decided that a meteor impact destroyed dinosaurs? What were the details?

In 2010, a panel of 41 experts gathered & decided that a meteor landed off the coast of the yucatan peninsula in Mexico. While this did trigger the extinction, it was decided that the dinosaur population was going into extinction anyway.


What type of Saurischian do fossilized birds share features with?


What is the name of the fossilized bird featured in class and what were its features?

Archaeopteryx, had reptile skull, tail, hands w/ digits, but had feathers.

How did feathers and wings develop in the first place? What functions do feathers serve?

Developed for insulation. Feathers serve as insulation, flight.

What class are birds in? What morphological features do birds have to reflect the demands of flight?

Class Aves. Birds have hollow bones, adapted respiratory system, no teeth, endothermy, keen vision.

What are feathers made from? What are their features?

Feathers are derived from keratin. They are light, but flexible. The quill, and the feathers have hooks that interlace, need preening. Barbs come off of the shaft, have hooks and barbules that cross each other.

What adapdations to the skeleton do birds have? Bones? Vertebrate? Sternum (keel)? Ribs? Forelimbs?

Bones are hollow, vertebrate fused, large keel, but reduced in flightless birds (called Ratites), ribs fused to vertebrate, forelimbs have feathers. Diapsid ancestry not obvious. Keel houses muscles for flight. Forelimbs are modified for flight but w/ basic tetrapod elements.

What adaptations to respiration do birds have (air sacs)?

When birds breathe, their air first goes into the posterior air sacs, then to the lungs, then again to the anterior air sacs to have a continually fresh amount of air in the lungs at all times.

How are the birds’ hearts more efficient?

They are large 4-chambered hearts

Are birds exo- or endothermic? What is their appetite like?

Endothermic, they have a voracious appetite.



Mammals; Primate Evolution

The Rise of mammals:

What type of skull (anapsid, synapsid, diapsid) do mammals have?


What two types of animals were the “forerunners” of mammals?

Pelycosaurs and Therapsids.

When did the first true mammals appear in the fossil record?

220 MYA

Class Mammalia:

What is hair made of? What function does hair form? Is it unique to mammals?

Hair is derived from keratin, serves as insulation, camoflage, sensory (whiskers), porcupine spines.. All mammals have hair, it is unique to mammals.

What function do the mammary glands serve?

Feed milk to suckling babies, but not all do it the same way.

Not only are mammals endothermic, but they have a relatively constant body temperature. What is this called? What substance provides insulation?

Homeothermy. Fat provides insulation.

Are all mammals homeothermic? What can smaller animals do?

Most are. Some animals can temporarily change their body temperatures.

Do all mammals have a placenta? What is its function?

Most do. Its function is to pass nutrients to a fetus when it is developing. Serves as provisional lungs, intestines, & kidneys of fetus – replaced shelled egg.

What modifications to the amniotic egg does the placenta have?

Amnion unchanged. Yolk sac reduced, allantois contributes to umbilical cord, chorion forms the placenta

Since mammals have specialized teeth, the teeth can often reveal the feeding habits. What functions do the incisors, canine, and molar/premolar teeth serve?

Incisors – Chiseling, canine – ripping, molar/premolar – grinding.

What teeth do carnivores have? Primates? Grazing herbivores? Gnawing herbivores? Piscivores?

Carnivores – sharp. Primates – omnivores, mixed dentition. Grazing herbivores – grinding teeth. Gnawing herbivores – sharp front teeth. Piscivores – homodont dentition.

What adaptation for herbivory to mammals have? What can mammals not digest without help from mutualistic bacteria?

They have mutualistic bacteria in the gut, otherwise they cannot digest cellulose.

What substance are hooves, claws, and fingernails derived from?


What is the difference between horns and antlers? Which one has a sheath of keratin?

Horns are permanent, antlers fall off every year. Horns have a sheath of keratin.

Only two known organisms are monotremes. What are the two organisms? What classifies monotremes?

Echidna, platypus. These two organisms lay eggs, but still give milk to their young, though not directly.

What classifies marsupials? What organisms are marsupials?

Have a pouch that the fetus continues to develop in. Kangaroos, koala bears.

What classifies placental mammals? How many orders of Placental Mammals are there?

Placental mammals have a placenta that the fetus grows in. There are 17 orders of placental mammals.


What are the two key features of primates?

Binocular vision and grasping fingers (opposable digits)

What are the promisians?

Nocturnal primates.

What are the new world monkeys?

All are aboreal, have a prehensile tail.

What are the old world monkeys and apes?

Some are aboreal, but no prehensile tail, live on the ground (most).

The new world monkeys and old world monkeys/apes are both anthropoids. What does this mean?

Larger brain size, diurnal, color vision.

What is the primate phylogeny?

There are promisians, followed by old world monkeys, then new world monkeys, then homonoids (chimpanzees are closest to humans)

Human Evolution:

Why is the old view of human evolution misguided?

Because humans did not evolve from chimpanzees, rather we both evolved from an ancestor of both.

Where are Australopitheus afarensis, Homo habilis, Homo erectus, Homo neanderthalensis, and Homo sapiens sapiens located in relation to each other on a phylogenic tree?

Remember the pneumonic HENS

Which of these species has the largest brain? Which of these species has evolved most recently?

Largest brain is the neanderthalensis, and homo sapiens has evolved most recently.


What skeletal modifications do humans have from chimpanzees that allow them to walk on two feet? When did bipedalism evolve in relation to larger brain size? When were hominid footprints found?

Hips drive towards ground, hold organs better. Bipedalism (4mya) evolved before larger brain size (2mya) (thanks Lucy). Homonid footprints were found 3.7 mya


What are the basic features of Australopithecus?

4.2-1 Mya Small 1m tall, no tools bipedal, brain ape-sized (lucy)

What are the basic features of Homo habilis?

1.9-1.6 Mya Larger brain, tools found with bodies, otherwise similar to Australopithecus.

What are the basic features of Homo erectus?

1.5-0.13 Mya 1.5m tall, had tools as well. large brain, suggest speech, social groups, fire, tools, hunters, migrated from Africa to Asia & Europe

What are the basic features of Homo neanderthalensis?

500,000-34,000 Ya Short, stalky, powerful, huge head, prominent brow ridge, made tools, buried dead

What are the basic features of Homo sapiens?

Tall, reduced brow ridge, smaller brain size, art, symbolic language, societies, appearance of cro-magnon man in Europe coincides w/ disappearance of Neanderthal. Handled climate better than Neanderthals? Extermination?

How did humans migrate out of Africa?

Migrated out of Africa to the middle east, Europe, and asia, then across the sea to Australia and the Americas.



Musculoskeletal System

Skeletal Systems:

What are skeletal systems?

Skeletal systems provide strength & structure, and attachment point for muscles.

How does a Hydrostatic skeleton work?

Muscles are contracted against coelomic fluids.

What are examples of muscular skeletons? Why is it not found more in nature?

Tongues, octopus, elephant trunk. Too complex, takes lots of energy.

What phylum has exoskeletons? What is an exoskeleton and what limitations does it have?

Phylum arthropoda has exoskeletons. An exoskeleton is made of chitin and has to fall off at certain points so the animal can continue to grow. Also serves as an internal attachment site for muscles.

What is an endoskeleton? What advantages does it have? What two substances is the endoskeleton made out of?

An endoskeleton is a skeleton that continually grows so that it does not have to fall off. It can be made of cartilage or bone, both of which are living tissues.


What is bone? How does bone differ from cartilage? (pg 870 in text)

Bone is stronger, has spongy bone inside that contains bone marrow, but not as flexible. Consists of osteocytes in a matrix of collagen and CaPO4 crystals. Nourished by blood vessels (unlike cartilage).

What is endochondral bone?

Bone that makes up the skeleton of the body.

Why are bones hollow? What is inside of the bone?

Bones produce blood cells from bone marrow which is on the inside of the bone.

Joints and Types of Movement:

How does the ball and socket joint work?

One point of attachment, greater flexibility, but more muscles needed.

How does the hinge work?

Two points of attachment, only 1 pivot for movement (knees and elbows)

How does the gliding joint work?

Two bones glide against each other (vertebrate discs)

In what body part are some of these joints combined?


How do muscles move these limbs?

By contracting and pulling towards which way you want it to go. Another muscle is needed to contract back to the starting position.

Muscle Tissues:

Where are smooth muscles located? What makes it different from skeletal and cardiac muscle?

Smooth muscles are uninucleate, unstriated, autonomic control, slow acting

What is skeletal muscle?

Multinucleate, cranial control, striated, fast-acting

What is cardiac muscle? Where can this muscle be found?

Uninucleate, striated, fast-acting, autonomic control.

Muscle Contraction:

How is muscle composed?

Muscle is composed of many strands of muscle fibers

What is the difference between an actin and myosin filament?

Thin Actin filament surrounds the thick myosin filament

How does the sliding filament model of muscle contraction work?

Z-lines are structures that anchor the actin filaments, but the actin filament that surrounds the myosin filament will contract these together for the fibers to move. A myofibril unit, called a sarcomere, extends between two successive z-lines. The fiber shrinks, but the filaments remain the same size. During muscle contraction, myofilaments do not contract whereas myofibrils do.

How does ATP and ADP play a role in muscle contraction? How does Ca++ play a role?

ATP binds to the myosin head, which then splits into ADP + P. This binds to the actin filament and pulls the actin filament closer. When a muscle is relaxed, the myosin heads are not bound to actin. Tropopmyosin blocks the myosin heads from binding to actin .To contract a muscle, tropomosin must be moved out of the way. This is controlled by the regulatory protein troponin. When nerves signal muscles to contract, Ca++ is released from the sarcoplasmic reticulum (a cell organelle). Ca++ binds to troponin, which alters the configuration of the troponin-tropomyosin complex & allows the myosin heads to bind to actin.

How does a nerve stimulate contractions? How does the neurotransmitter acetylcholine (ACh) affect nerve stimulation?

A nerve will bind to the muscle fiber and transfer ACh, which tells the muscle to react.

Since muscle contraction is an all-or-nothing thing, how is this controlled when less/greater muscle is needed?

Less muscle fibers are activated

What two factors influence the size of a muscular response?

Number of motor units recuited, and the motor unit (the number of muscle fibers contacted by the axonal branches of a motor neuron)

How is energy obtained for muscle contractions (how is ATP made)?

From food, glycogen & blood glucose are oxidized to generate ATP. With heavy exercise, skeletal muscles respire anaerobically for the first 45-90 seconds until cardiopulmonary system catches up (breathing heavier)

How long does it take during sudden exercise for the skeletal muscles to stop respiring anaerobically?

45-90 seconds, lactic acid develops.



Feeding and Digestion

Mechanisms of Feeding:

What is meant by the term heterotroph?

Consumes other organisms

With particulate feeders, what are suspension feeders? What are the 5 phyla that are suspension feeders?

Suspension feeders are attached to a substrate. 5 phyla are porifera, cnidaria, annelida, molluska, chordata

With particulate feeders, what are deposit feeders? What is an example of an organism that does this?

Deposit feeder is one that eats dirt (consumes substrate). Earthworm for instance.

With particulate feeders, what are filter feeders? How do humpback whales filter feed?

Filter feeders actively consume smaller organisms. Humpback whales use bubblenet feeding, where they blow bubbles around a school of fish, which scares them and forces them to the surface, then a group of humpback whales all shoot up at the same time, eating all of the fish.

What are predators? Herbivores? Omnivores? Fluid feeders?

Predators consume organisms and hunt one-on-one. Herbivores eat plants (require microbes to digest cellulose), omnivores are adapted for a range of food types, and fluid feeders drink fluids (hummingbirds, vampire bats, mosquitos) – ALL CAN FLY!!!

Types of Digestive Systems:

What are the two types of digestive systems that invertebrates use?

If they have a digestive system, they can have a blind digestive tract (NO SPECIALIZATION) or a one way digestive tract (SPECIALIZATION).

Vertebrates have a one way digestive tract. What are the significant organs involved?

Mouth, esophagus, stomach, liver, pancreas, large intestine, small intestine, colon, cecum, kidneys.

Mouth and Teeth:

What is the function of teeth? How do teeth reflect diet in vertebrates?

Teeth masticate food, makes for easier swallowing and digestion. Different types of teeth reflect different diets.

Does saliva simply lubricate the mouth, or does it also have a role in the chemical breakdown of food?

It plays a role in breaking down food because it has the enzyme amylase.

Esophagus and Stomach:

What is peristalsis? What anatomical structure in humans controls the passage of food from the esophagus to the stomach?

Peristalsis is rhythmic movement of food down the esophagus to the stomach. The cardiac sphincter controls movement.

What structures do birds, earthworms, and some invertebrates have for storing food prior to its arrival in the stomach?

A crop.

What is the function of the gizzard in birds? Would you expect a gizzard to be muscular?

It grinds up the food for easier digestion. Very muscular.

What is the function of the gastric mill in crustaceans such as the crayfish?

Same as the gizzard in birds and other animals.

What three substances are secreted into the stomach? Describe the role(s) of each.

HCl – kills bacteria, causes (inactive) pepsinogen to unfold & transform into (active) pepsin, a protease. Some protein digested; little digestion of carbohydrates & fat.
Mucus – protects stomach lining
pepsinogen – breaks down food.

What is the cause of most stomach ulcers – spicy food?

Breakdown of mucus lining in stomach. – cause by bacterium Heliobacter pylori – may weaken the mucosal lining, causing ulcers.


Describe the path of food from the stomach to the large intestine.

From the stomach, food moves to the small intestine (duodenum, jejanum & ileum). The pancreas secretes juices to the duodenum (part of the small intestine), at which point more nutrients are absorbed, then the rest of the material goes into the large intestine where it is dehydrated and condensed.

What is the function of the pancreas? Where is the pancreas located? Does this make sense given its function?

The pancreas is located next to the small intestine. The pancreas pumps fluids into the small intestine.

What is bile and what is it used for? What two substances does bile produce?

Bile is produced by the liver, stored in the gall bladder, & transported to the duodenum. Consists of:
1: Bile pigments – worn out blood cells that are ultimately eliminated in feces
2. Bile salts – help eliminate fat.

What is the function of villi and microvilli in the small intestine?

These increase the surface area of the small intestine for greater nutrient absorption.
Digested proteins & carbohydrates are transported via the hepatic portal

Describe the position of the large intestine (colon) relative to the rest of the alimentary canal. What is its function? Is the colon in humans adapted for high fiber or low fiber diets?

Large intestine (colon) begins at the point where the appendix and cecum meet the small intestine. High fiber diets in humans. The large intestine wraps around the small intestine and ends.

Variations in Design:

Animals cannot produce the enzymes needed to break down cellulose. Nevertheless, many animals are herbivores. How do they circumvent this problem?

Mutualistic bacteria in gut.

What is a ruminant stomach? What is the rumen?

A ruminant stomach contains a rumen that houses bacteria necessary to break down cellulose. Found in cows and other grazing herbivores.

What do non-ruminant herbivores have (non-ruminant modifications to the gut)?

Large cecum.

What is coprophagy? Identify two groups of animals that engage in this behavior. What purpose does it serve?

Re-eating feces. Some animals do not fully digest their food, so there are still nutrients in the excrement to be absorbed. The two animals are????




Components of Blood:

What are the three functions of blood?

Transport: Transports oxygen, nutrients, wastes to different parts of body. Oxygen is transported by red blood cells. It attaches to hemoglobin within erythrocytes. Blood also carries absorbed products of digestion through the liver & to cells in the body. Metabolic wastes & excessive water in the blood are filtered through the kidneys & excreted in urine.
Regulation: Regulates temperature and hormones are secreted into blood from the glands.
Protection: Clotting, immune defense.

What three substances make up blood? What are their purposes? What is the difference between erythrocytes and leucocytes?
Blood plasma: 92% water, contains dissolved metabolites, wastes, antibodies, hormones, ions, & proteins. Source of interstitial fluid. Serves as a matrix for red blood cells, white blood cells, & platelets.
Blood cells
Erythrocytes: red blood cells, develop from stem cells in bone marrow.  NO NUCLEUS, biconcave. Hemoglobin is a pigment that binds to O2, blood transports oxygen to different parts of body
Leucocytes: white blood cells, immune response Also found in interstitial fluid.
Platelets: Fragments of blood cells produced by bone marrow, necessary for clotting blood.

How does the clotting process take place? What is coagulation?

A broken blood vessel is clotted by blood platelets that bind to the vessel to prevent further blood loss. Coagulation is when the platelets adhere to damaged blood vessels to form a plug. Threads of the protein fibrin also serve to reinforce the clot.

Invertebrate Circulatory Systems:

What two types of organisms do not require a circulatory system?

Parazoans, simple metazoans.

What are the two circulatory systems invertebrates can have? What is the difference between the two?

Either Open or closed. Open is when the “hemocoel” is mixed, not really blood, mixed with other fluids of body.  Found in arthropods and mollusks (except cephalopods) – NOT associated w/ O2 transport in insects – IMPORTANT!!!

Closed is then the blood is separate, circulation is separate as well. Found in annelids and cephalopods.

Vertebrate Circulatory Systems:

What organism has a single loop circulation? How does this work? How many chambers does the heart have?

Fishes have single loop circulation. Blood is pumped from heart to gills, to body, back to heart. Very low pressure system, limited. Two-chambered heart.

What organisms have double loop circulation with a three-chambered heart?

Amphibians & most reptiles

What are the two different circuits and what is the pressure/function of each?

Pulmonary circuit – blood pumped to lungs and back
Systemic circuit – blood pumped to body and back.

In double loop circulation with a four-chambered heart, what are the four chambers and what are their functions?

Right Atrium: Receives venous blood from body, goes to right ventricle
Right Ventricle: Pumps blood to lungs & blood goes to left atrium
Left Atrium: Receives oxygenated blood from lungs, pumps to left ventricle.
Left Ventricle: Pumps blood to body & flows to Right Atrium.

Blood Vessels:

What are the functions of arteries, capillaries, and venules/veins?
Arteries are large tubes through which blood can flow – elastic fibers. Capillaries are where the blood is deoxygenated, and venules/veins keep the blood flowing one way-back to the heart.

What is the function of the lymphatic system?

The lymphatic system’s function is immune response.

Is the lymphatic system open or closed? Explain.

Open. The amount of fluid flowing back to the capillaries is lower than the amount given off.

Excess interstitial fluid drains into lymph capillaries, which eventually passes to lymph nodes (in neck) and drains back into veins.



Respiratory Systems

Gas Exchange across Respiratory Surfaces:

What is respiration?

Diffusion of gases across plasma membranes. Diffusion is passive, driven by the difference of CO2 and O2 concentrations across a membrane.

What is Fick’s Law of Diffusion (hint: it’s an equation)? What are the variables?

R= rate of diffusion
D = diffusion constant
A = surface area
Dp = difference in concentration on either side of membrane
d = width of membrane

How is Fick’s law applied?
Raise A or Dp, or lower d, and the rate of diffusion is higher

Gills, Cutaneous Respiration, Tracheal Systems:

How do gills work? Why don’t they work on land?
Gills filter oxygen out of water. They don’t work on land because they require moisture and would collapse without water.

How does cutaneous respiration work? What organisms have this ability?

Cutaneous respiration is powered by an extra vessel coming out of the three-chambered heart. Oxygen is absorbed through the skin (when moist) and blood is oxygenated that way. Amphibians and some aquatic reptiles can do this.

How does the tracheal system in insects (terrestrial arthropods) work?
Trachea and tracheal tubules deliver oxygen to all parts of body.


What is a lung?
A chamber that fills with oxygen and allows blood to absorb oxygen – MOIST, minimizes evaporation

What are the four types of lungs we looked at in class with varying complexity?
Amphibian, reptile, bird, human.

How do amphibians respire?

Cutaneously & have lungs. The frog “swallows” air into lungs, takes extra effort and not very ideal – positive pressure – not negative pressure.

How does breathing in reptiles differ from amphibians?

Reptiles can breathe with lungs and can’t breathe cutaneously. Also have more adapted lungs, but not as adapted as mammals.

How do birds respire (think four-stroke engine, four steps)?

Inhale 1: Air goes to posterior air sacs
Exhale 1:Air transported to lungs, passes over parabronchi (air vessels)
Inhale 2: Air transported to anterior air sacs
Exhale 2: Air leaves the bird.

How do mammals respire? What role to intercostal muscles play?

Mammals respire by actively contracting intercostal muscles, which expand the lungs and create negative pressure. Thus, the lungs fill with air. When the intercostal muscles relax, the lungs naturally retract and release CO2.


When the intercostal muscles are contracted, this raises the ribs & expands the thoracic cavity. Contraction of the diaphragm lowers base of the thoracic cavity. Relaxation of these muscles allows elastic forces to expel air.