TRY OUT CLASS XI SEMESTER 2

1. An antigen is

a. a protein molecule that helps defend the body against disease.

b. a type of white blood cell.

c. an invading virus or bacterium.

d. a foreign molecule that evokes a specific response by a lymphocyte.

e. a body cell attacked by an invading microorganism.

2. How do memory cells differ from effector cells?

a. Memory cells are more numerous.

b. Memory cells are responsible for the primary immune response.

c. Memory cells combat antigens; effector cells do not.

d. Memory cells live longer.

e. Memory cells are capable of producing antibodies.

3. Following tissue damage or the entry of microorganisms, an inflammatory response may be initiated by

a. the accumulation of phagocytes in an injured area.

b. the release of interferon by infected cells.

c. an increased blood flow in an infected or injured area.

d. the ensuing fever.

e. the release of chemicals such as histamine by damaged cells.

4. Which of the following could be considered a nonspecific defense?

a.    Intact skin creates a barrier that cannot normally be penetrated by bacteria or viruses.

b.    Secretions from sebaceous and sweat glands give the skin an acidic pH that prevents bacterial colonization.

c.     Tears, saliva, and mucous secretions contain lysozome, an enzyme that digests the bacterial cell wall.

d.    Mucus traps microbes and other particles that contact it.

e.    all of the above

5. During a secondary immune response

a.    selected B cells generate antibody-producing effector B cells called plasma cells.

b.    the stricken individual may become ill.

c.     about 10 to 17 days are required from exposure to maximum effector response.

d.    the generation of effector cells begins with memory cells produced during the primary immune response.

e.    all of the above

6. Most individuals infected with HIV

a. can live for 15 to 20 years.

b. never develop AIDS.

c. die from autoimmune reactions.

d. suffer from increased sensitivity to foreign antigens.

e. die from other infections or cancer.

7. Tissues are typed before an organ transplant to make sure that the _____ of donor and recipient match as closely as possible.

a. T cells

b. antibodies

c. MHC (major histocompatibility complex) proteins

d. histamines

e. B cells

8. A vaccine contains

a. white blood cells that fight infection.

b. antibodies that recognize invading microbes.

c. inactivated disease-causing microbes.

d. a hormone that boosts immunity.

e. lymphocyte antigens.

9. When you are immune to a disease,

a. antibodies against the disease are constantly circulating in your blood.

b. certain lymphocytes are able to make the proper antibodies quickly.

c. your nonspecific defenses are strengthened.

d. B cells are stimulated to quickly engulf invaders.

e. antigens are altered so invaders can no longer attack your tissues.

10. In a series of immune system experiments, the thymus glands were removed from baby mice. Which of the following would you predict as a likely result?

a. The mice suffered from numerous allergies.

b. The mice never developed cancerous tumors.

c. The mice suffered from autoimmune diseases.

d. The mice readily accepted tissue transplants.

e. The mice were unable to produce an inflammatory response.

11. Which of the following is not initiated by binding of antibodies to antigens?

a. activation of complement proteins

b. secretion of interferon by infected cells

c. neutralization

d. agglutination

e. precipitation

12. The antigen-binding sites of an antibody molecule are formed from the molecule's variable regions. Why are these regions called variable?

a. They can change their shapes on command to fit different antigens.

b. They change their shapes when they bind to an antigen.

c. Their specific shapes are unimportant.

d. They can be different shapes on different antibody molecules.

e. Their sizes vary considerably from one antibody to another.

13. The biggest difference between cell-mediated immunity and humoral immunity is

a. how long their protection lasts.

b. whether a subsequent secondary immune response can occur.

c. whether clonal selection occurs.

d. how they respond to and dispose of invaders.

e. how fast they can respond to an invader.

14. Viruses and bacteria in body fluids are attacked by

a. antibodies from B cells.

b. cytotoxic T cells.

c. complement proteins.

d. helper T cells.

e. antigens.

15. What do the antibodies secreted by plasma cells (the effector cells of humoral immunity) do to attack their targets?

a. activate complement to punch holes in them

b. clump cells together so that phagocytes can ingest them

c. cause antigen molecules to settle out of solution

d. attach to antigens and detoxify them

e. all of the above

16. Tissue macrophages

a. begin their lives as neutrophils.

b. have short life spans because they self-destruct after engulfing foreign invaders.

c. originate from monocytes that leave the circulation and enter the tissues.

d. are most effective against parasites.

e. do not attack microorganisms directly; instead, they destroy virus-infected body cells.

17. The idea behind vaccination is to induce _____ without the vaccinated individual having to get sick.

a. passive immunity

b. the primary immune response

c. anaphylactic shock

d. nonspecific defenses

e. inflammation

18. A group of researchers have tested many chemicals and found several that have potential for use in modifying the action of the immune system. Which of the following would seem to have the most promise as a drug for inhibiting transplant rejection?

a. Compound A13: acts like histamine

b. Compound Q6: stimulates cytotoxic T cells

c. Compound N98: a potent allergen

d. Compound B55: suppresses specific cytotoxic T cells

e. Compound M31: stimulates helper T cells

19. The body produces antibodies complementary to foreign antigens. The process by which the body comes up with the correct antibodies to a given disease is most like

a. going to a tailor and having a suit made to fit you.

b. ordering the lunch special at a restaurant without looking at the menu.

c. going to a shoe store and trying on shoes until you find a pair that fits.

d. picking out a video that you haven't seen yet.

e. selecting a lottery prize-winner by means of a random drawing.

20. B lymphocytes

a. attack cells that have been infected by viruses.

b. engulf and destroy bacteria and viruses.

c. multiply and make antibodies that circulate in blood and lymph.

d. stimulate other lymphocytes.

e. produce interleukin-2.

 

hapter 44

1. Which of the following is an endotherm?

a. mouse

b. iguana

c. frog

d. trout

e. all of the above

2. What conditions are responsible for the stimulation of the JGA?

a. an increase in blood pressure and/or blood volume within the heart

b. an increase in the solute concentration of the blood plasma

c. a decrease in the solute concentration of the blood plasma

d. a decrease in the blood pressure and/or blood volume in the afferent arteriole

e. consumption of alcohol

3. As filtrate passes through the long loop of Henle, salt is removed and concentrated in the interstitial fluid of the kidney medulla. Because of this high salt concentration, the nephron is able to

a. excrete the maximum amount of salt.

b. neutralize toxins that might accumulate in the kidney.

c. control the pH of the interstitial fluid.

d. excrete a large amount of water.

e. establish a hypertonic interstitial medullary concentration.

4. The kidney's filtration process is nonselective, so

a. many valuable substances are lost in the urine.

b. the proportions of substances in urine are the same as in blood.

c. urine is much less concentrated than blood.

d. it really has little control over body fluid composition.

e. useful substances must be selectively reabsorbed.

5. A countercurrent heat exchanger enables an animal to

a. produce more heat when needed.

b. reduce loss of heat to the environment.

c. slow metabolism when food is not available.

d. increase heat loss by evaporation.

e. absorb heat from the environment.

6. Uric acid is the nitrogenous waste excreted by birds, insects, and many reptiles. An advantage of excreting uric acid is that it ____ , but a disadvantage is that it _____ .

a. saves water . . . costs energy

b. saves energy . . . is highly toxic

c. is not very toxic . . . wastes a lot of water

d. is much more soluble in water than other wastes . . . costs energy

e. saves water . . . is highly toxic

7. Which of the following is the most accurate and comprehensive description of the function of the kidneys?

a. breaking down body wastes

b. excreting wastes

c. regulating body fluid composition

d. filtering the blood

e. producing urine

8. Which of the following would be filtered from blood but not normally found in urine?

a. water

b. red blood cells

c. H+ ions

d. amino acids

e. urea

9. On a cold day, blood vessels in the skin

a. dilate, allowing blood to keep the skin warm.

b. constrict, forcing blood to flow through vessels in the skin.

c. constrict, reducing heat loss from blood at the surface.

d. dilate, causing blood to pass through the cold skin more quickly.

e. dilate, preventing blood flow to the surface.

10. The animals in which of these pairs have similar problems regulating water balance?

a. freshwater fish and saltwater fish

b. land animal and freshwater fish

c. osmoconformer and freshwater fish

d. salmon in fresh water and salmon in salt water

e. saltwater fish and land animal

11. The filtrate formed by the nephrons in the kidney is not the same as urine. The filtrate is first refined and concentrated by the processes of ______ , forming the urine that leaves the body.

a. filtration and secretion

b. reabsorption and secretion

c. reabsorption and excretion

d. filtration and reabsorption

e. secretion and excretion

12. By definition, an ectotherm

a. is cold-blooded.

b. is warm-blooded.

c. obtains most of its heat from its environment.

d. derives most of its heat from its own metabolism.

e. has a body temperature that varies considerably.

13. Which would have the toughest time surviving over the long term in the environment given?

a. an osmoconformer in seawater

b. an endotherm in a warm environment

c. an ectotherm in a cold environment

d. an osmoregulator in seawater

e. an ectotherm in a warm environment

14. Most aquatic animals excrete ammonia, while land animals excrete urea or uric acid. What is the most likely explanation for this difference?

a. They have different diets.

b. Land animals can get the energy needed to make urea or uric acid.

c. Ammonia is very toxic, and it takes lots of water to dilute it.

d. Land animals cannot afford the energy needed to make ammonia.

e. Fish need to get rid of ammonia, but land animals need it to live.

15. The appropriate group of animals to examine to observe a Malpighian tubule would be

a. flatworms.

b. annelids.

c. insects and other terrestrial arthropods.

d. amphibians.

e. birds.

16. Which of the following primarily involves heat transfer by convection?

a. You roll down the car window to let the cool breeze blow through.

b. The water in the lake is so cold that your legs become numb.

c. You sweat profusely as you mow the lawn on a hot summer day.

d. After sunset, you can feel heat from the warm pavement.

e. As you lie on the sand, you can feel the sun's warm rays on your skin.

17. The loops of Henle in the kidneys of a desert kangaroo rat are much longer than those in a white laboratory rat because

a. the kangaroo rat is adapted to living in an environment where water is scarce.

b. the white rat's diet is much less varied than the kangaroo rat's.

c. the kangaroo rat cannot always find food.

d. the kangaroo rat produces more body wastes.

e. the kangaroo rat has less stress and lower blood pressure.

18. Humid weather makes you feel warmer because humid air

a. interferes with heat loss by conduction.

b. holds warm water vapor.

c. interferes with heat loss by evaporation.

d. prevents countercurrent heat exchange from occurring.

e. increases metabolic heat production.

19. In each nephron of the kidney, the glomerulus and Bowman's capsule

a. filter the blood and capture the filtrate.

b. reabsorb water into the blood.

c. break down harmful toxins and poisons.

d. reabsorb salts and nutrients.

e. refine and concentrate the urine for excretion.

20. During kidney dialysis, blood and a dialyzing solution are separated by a semipermeable membrane. For kidney dialysis to work properly, the dialyzing solution should contain

a. a lower solute concentration than blood.

b. a higher concentration of urea than blood.

c. a lower glucose concentration than blood.

d. a lower concentration of urea than blood.

e. a much smaller volume of fluid than the blood passing through it.