Bio 109 Exam 3

Four students carried out studies to determine whether a newly discovered animal was an ectotherm or endotherm. Each student made one observation and one conclusion. Which is the correct conclusion based on the observation?

A B Correct Answer C D

Which of the following statements concerning an open circulatory system is true?

A heart is not required to pump the circulatory fluid. An open circulatory system has higher pressure and is less energy efficient than a closed system. Correct Answer The circulatory fluid is also the interstitial fluid. The circulatory fluid does not require respiratory pigments for O2 transport. The lower pressures provide for more effective delivery of O2 than is possible with a closed system.

If the atrioventricular node (AV node) were surgically removed from the heart without disrupting signal transmission to the Purkinje fibers, what would happen?

Atria and ventricles would contract at approximately the same time.

Blood travels around the body through arteries, veins and capillaries. Which of the following correctly describes the structure or function of each of these blood vessels?

B

The minimum metabolic rate of an endotherm that is at rest, has an empty stomach, and is not experiencing stress is called:

Correct Answer BMR SMR STP ATP ECG

Three groups of cyclists consumed three different types of diets: high-carbohydrate; a diet of mixed carbohydrates, fat, and protein; or a diet higher in protein and fat. The average time each group could spend cycling over a six-hour period is shown in the graph. What conclusion from the data should a trainer tell athletes to improve their performance?

Correct Answer Maintaining elevated blood sugar improves performance. An early 50 percent drop in blood glucose is associated with improved endurance. Diet is not related to endurance. A mixed diet yields the most improvement in long-term endurance.

These autorhythmic cells located in the wall of the right atrium control the rate and timing at which all cardiac muscle cells contract.

Correct Answer Sinoatrial (SA) node Atroventrical (AV) node Semilunar (SL) node Purkinje fibers Bundle branches

All of the following are part of our antigen-specific defense mechanisms (adaptive immune response) except:

Correct Answer acute inflammation lymphocytes antibody production macrophages

Ammonia

Correct Answer is soluble in water. has low toxicity relative to urea. is metabolically more expensive to synthesize than urea. is the major nitrogenous waste excreted by insects. is the major nitrogenous waste product excreted by humans and birds.

Which of the following animals is correctly paired with its feeding mechanism?

Correct Answer snake - bulk feeder baleen whale - fluid feeder clam - substrate feeder grasshopper - suspension feeder

Which of the following statements comparing the endocrine system (ES) and nervous system (NS) signaling is true?

Hormones are fast acting, but effects often short-acting. In ES signaling, all body cells can respond to the circulating hormone. Nerve impulses can be received by all cell types within the body. Correct Answer The NS transmits a signal to a target cell via a specific pathway. ES transmission is very fast compared to NS transmission.

Compare an animal with a gastrovascular cavity to an animal with a tube-type digestive system. What is(are) the major advantage(s) of having a tube?

It allows the animal to consume a second meal while the first is being digested. It permits development of specialized enzymes and concentration of digestive juices in different regions. It permits more time for enzymatic action. Additional physical cutting and grinding of the food bolus is made possible. Correct Answer All of the above are advantages

Individuals whose diet consists primarily of corn would most likely become:

Malnourished

How do the digestion and absorption of fat differ from the digestion and absorption of carbohydrates?

Most absorbed fat first enters the lymphatic system; carbohydrates directly enter the blood.

How is positive feedback different from negative feedback?

Positive feedback benefits the organism, but negative feedback is harmful. Correct Answer Positive feedback's effector responses are in the same direction as the initiating stimulus, whereas negative feedback's effector responses are in the opposite direction. In positive feedback, the effector's response increases some parameter (such as body temperature), whereas in negative feedback the parameter decreases. Positive feedback systems have only effectors, whereas negative feedback systems have only receptors. Positive feedback mechanisms are more frequently encountered in the control of homeostasis than negative feedback mechanisms.

Which of the following most accurately describes selective permeability?

Question 194.5 / 4.5 pts Which of the following most accurately describes selective permeability? An input of energy is required for transport. There must be a concentration gradient for molecules to pass through a membrane. Correct Answer Only certain molecules can cross a cell membrane. Molecules diffuse against their concentration gradients.

Fluid is forced out of systemic capillaries at the arteriolar end because:

The blood pressure is greater than the osmotic pressure of the blood.

Fat absorption differs from other foods because its breakdown products are:

absorbed into the lacteals before entering into the lymphatic system.

One of the waste products that accumulates during cellular functions is carbon dioxide. It is removed via the respiratory system. What other waste products may accumulate during normal physiological functioning in a vertebrate?

ammonia, uric acid, and urea

During exhalation in humans, air moves from the bronchus into the:

bronchioles alveoli nostrils pharynx Correct Answer trachea

A renal physiologist wants to determine the rate of filtration in the glomeruli of the kidneys. The best experimental design would be to inject a substance into the blood which:

can pass through the glomerular capillaries and is not reabsorbed in the renal tubules.

The exchange of gases between interstitial fluid and the blood occurs in:

capillaries

When a B cell or T cell encounters an antigen for which it has an antigen receptor, the B or T cell will divide repeatedly to make copies of itself. This process is called:

clonal selection

__________________is the transfer of thermal energy between an object and an external fluid that is moving (e.g., water or air).

conduction Correct Answer convection evaporation radiation sublimation

Which type of T cell lyses cells that have been infected with viruses?

cytotoxic T cells

During inhalation:

diaphragm and rib muscles contract.

If two solutions that differ in their osmolarity are separated by a selectively permeable membrane (permeable to water only), the net flow of water is:

equal in both directions. from the hyperosmotic to the hyposmotic solution. Correct Answer from the hyposmotic to hyperosmotic solution. from the solution containing less free water to the solution containing more free water.

A human who has no access to fresh water but is forced to drink seawater instead will:

excrete more water molecules than taken in, because of the high load of ion ingestion.

If blood glucose levels were to fall below 90 mg/100 ml you would expect levels of the hormone ________________ to increase and that of ________________ to fall.

glucagon, insulin

As filtrate moves down the loop of Henle, the surrounding interstitial fluid has a _____ osmolality than the filtrate, so _____ leave(s) the filtrate.

higher, water

The term _______ disease refers to any disorder in which an immune system response to antigens is defective or absent.

immunodeficiency

During this stage of food processing, the animal's cells take up small molecules such as amino acids and simple sugars.

ingestion digestion Correct Answer absorption excretion elimination

Compared with a smaller cell, a larger cell of the same shape has _____.

less surface area. Correct Answer less surface area per unit of volume. a smaller average distance between its mitochondria and the external source. a smaller cytoplasm-to-nucleus ratio. equal surface area per unit of volume.

Which of the following connective tissues consists of cells in a fluid matrix?

loose connective tissue adipose tissue bone Correct Answer: blood cartilage

A countercurrent system between substance A and substance B:

maximizes the exchange by having A and B flow in the same direction. minimizes the exchange by having A and B flow in the same direction. Correct Answer maximizes the exchange by having A and B flow in opposite directions. minimizes the exchange by having A and B flow in opposite directions.

B cells and T cells that do not immediately attack pathogens, but instead remain inactive until a future encounter with the pathogen, are referred to as:

memory B cells and memory T cells

The primary responsibility of this segment of the alimentary canal is the recovery of water that has entered the canal as the solvent of digestive juices.

microvilli Correct Answer large intestine stomach cecum pancreas

Which of the following is an autoimmune disease?

multiple sclerosis rheumatoid arthritis insulin-dependent diabetes mellitus systemic lupus erythematosus Correct Answer all of the above are autoimmune diseases.

When a B cell encounters an antigen to which it is targeted, it divides rapidly and produces:

plasma cells

Memory cells:

produce allergens. are responsible for passive immunity. prevent an animal from encountering certain antigens. Correct Answer provide an accelerated immune response upon second exposure to a particular antigen. all of the above.

Yearly vaccination of humans for influenza viruses is necessary because:

rapid mutation in flu viruses alters the surface proteins in infected host cells. v. memory cells are not formed upon exposure to the flu virus.

Which of the following is not a property of the adaptive immune system?

receptor diversity lack of reactivity against host cells immunological memory very specific response to pathogens Correct Answer rapid rate of response compared to the innate immune system

The inflammatory response includes all of the following except:

release of histamine by mast cells temperature increase increased blood flow phagocytosis Correct Answer blood vessel constriction

Birds secrete uric acid as their nitrogenous waste because uric acid:

requires little water for nitrogenous waste disposal, thus reducing body mass.

Marine birds eliminate excess salts through their:

salt glands in their heads

The type of muscle surrounding the intestines and blood vessels is _____.

skeletal muscle cardiac muscle intercalated cells Correct Answer smooth muscle striated muscle

Most enzymatic hydrolysis of the macromolecules of food occurs in the:

small intestine

Circulatory systems compensate for:

temperature differences between the lungs and the active tissue. Correct Answer the slow rate at which diffusion occurs over large distances. the need to cushion animals from trauma. all of the above.

Most types of communication between cells rely on:

the exchange of cytosol between the cells the movement of the cells Correct Answer chemical or electrical signals the exchange of DNA between the cells shortening of muscle cells

Vitamins are classified based on:

whether they affect carbohydrate or proteins. how much of them is required. the amount of energy they contain. Correct Answer whether they are water soluble or fat soluble.