What type of immunity is associated with breast feeding?
A) active immunity
B) cell-mediated immunity
C) innate immunity
D) passive immunity

Answer: D

To maintain homeostasis freshwater fish must ________.
A) excrete large quantities of electrolytes
B) take in electrolytes through simple diffusion
C) excrete large quantities of water
D) consume large quantities of water

Answer: C

The force driving simple diffusion ____, while the energy source for active transport is ____.
A) the concentration gradient; ATP
B) phosphorylated protein carriers; ATP
C) transmembrane pumps; electron transport
D)the concentration gradient; ADP

Answer: A

In animals, nitrogenous wastes are produced mostly from the catabolism of
A) starch and cellulose.
B) triglycerides and steroids.
C) proteins and nucleic acids.
D) phospholipids and glycolipids.

Answer: C

Birds secrete uric acid as their nitrogenous waste because uric acid
A) is readily soluble in water.
B) is metabolically less expensive to synthesize than other excretory products.
C) requires little water for nitrogenous waste disposal, thus reducing body mass.
D) excretion allows birds to live in desert environments

Answer: C

(DIAGRAM) The figure above shows a nephron. Filtration takes place int he structure labeled ________.
A) a
B) b
C) c
D) d

Answer: A

A fruit fly, internally infected by a potentially pathogenic fungus, is protected by
A) its plasma cells.
B) its immunoglobulins.
C) its antibodies.
D) its antimicrobial peptides.

Answer: D

The cells and signaling molecules that initiate inflammatory responses are
A) the phagocytes and the lysozymes.
B) the phagocytes and the chemokines.
C) the dendritic cells and the interferons.
D) the mast cells and the histamines.

Answer: D

The eyes and the respiratory tract are both protected against infections by
A) the mucous membranes that cover their surface.
B) the secretion of complement proteins.
C) the release of slightly alkaline secretions.
D) the secretion of lysozyme onto their surfaces.

Answer: D

Mammals have Toll-like receptors (TLRs) that can recognize a kind of macromolecule that is absent from vertebrates but present in/on certain groups of pathogens, including viral
A) lipopolysaccharides.
B) double-stranded DNA.
C) double-stranded RNA.
D) glycoproteins.

Answer: C

The cells involved in innate immunity, whose absence increases the chances of developing malignant tumors, are
A) cytotoxic T cells.
B) natural killer cells.
C) helper T cells.
D) macrophages.

Answer: B

You and a friend were in line for a movie when you noticed the woman in front of you sneezing and coughing. Both of you were equally exposed to the woman's virus, but over the next few days, only your friend acquired flu-like symptoms and was ill for almost a week before recovering. Which one of the following is a logical explanation for this?
A) You had an adaptive immunity to that virus.
B) Your friend had allergies.
C) Your friend had an autoimmune disorder.
D) Your friend had antibodies to that virus.

Answer: A

Clonal selection and differentiation of B cells activated by antigen exposure leads to the production of
A) short-lived plasma cells that secrete antibodies for the antigen.
B) large quantities of the antigen initially recognized.
C) vast numbers of B cells with random antigen-recognition receptors.
D) long-lived erythrocytes that can later secrete antibodies for the antigen.

Answer: A

An immunoglobulin (Ig) molecule, of whatever class, with regions symbolized as C or V, H or L, has a light chain made up of
A) one C region and one V region.
B) three C regions and one V region.
C) one H region and one L region.
D) three H regions and one L region.

Answer: A

Lymphocytes mature in the ________.
I) spleen
II) tthymus
III) bone marrow

A) I, II, and III
B) only I and II
C) only II and III
D) only I and III

Answer: C

Which of the following is a difference between B cells and T cells?
A) B-cells are activated by free-floating antigens in the blood or lymph. T cells are activated by membrane-bound antigens.
B) One has a major role in antibody production, while the other has a major role in cytotoxicity.
C) One binds a receptor called BCR (B-cell receptor), while the other recognizes a receptor called TCR (T-cell receptor).
D) T cells are produced in the thymus and B cells are produced in the bone marrow.

Answer: B

Phagocytosis of microbes by macrophages is enhanced by
I) the binding of antibodies to the surface of microbes
II) antibody-mediated agglutination of microbes.
III) the release of cytokines by activated B cells.

A) only I and III
B) only I and II
C) I, II, and III
D) only II and III

Answer: B

Naturally acquired passive immunity results from the
A) injection of vaccine.
B) ingestion of interferon.
C) placental transfer of antibodies.
D) absorption of pathogens through mucous membranes.

Answer: C

Which of the following components of the immune system destroys bacteria in a way similar to an antitank weapon destroying armored tanks by punching holes in the wall of the bacteria?
A) plasma cells
B) complement protein
C) major histocompatibility complex proteins
D) macrophages

Answer: B

A bone marrow transplant may not be appropriate from a given donor (Jane) to a given recipient (Jane's cousin Bob), even though Jane has previously given blood for one of Bob's needed transfusions, because
A) even though Jane's blood type is a match to Bob's, her MHC proteins may not be a match.
B) a blood type match is less stringent than a match required for transplant because blood is more tolerant of change.
C) for each gene, there is only one blood allele but many tissue alleles.
D) Jane's class II genes are not expressed in bone marrow.

Answer: A

Which of the following should be the same in identical twins?
A) the set of antibodies produced
B) the set of major histocompatability (MHC) molecules produced
C) the set of T cell antigen receptors produced
D) the susceptibility to a particular virus

Answer: B

Which of the following is the best definition of autoimmune disease?
A) a condition in which B cells and T cells respond independently to antigens and do not interact correctly
B) a condition in which self molecules are treated as non-self
C) a condition in which the adaptive immune system fails to recognize the second infection by the same antigen
D) a condition in which the immune system creates random antibodies without being triggered by an antigen

Answer: B

Single-celled Paramecium live in pond water (a hypotonic environment). They have a structural feature, a contractile vacuole, which enables them to osmoregulate. If you observed them in the following solutions, at which sucrose concentration (in millimolars, mM) would you expect the contractile vacuole to be most active?
A) 0.05 mM saline
B) 1.0 mM saline
C) 0.08 mM sucrose
D) 0.001 mM sucrose

Answer: D

The body fluids of an osmoconformer would be ________ with its ________ environment.
A) hyperosmotic; freshwater
B) isotonic; freshwater
C) hyperosmotic; saltwater
D) isoosmotic; saltwater

Answer: D

Ammonia is likely to be the primary nitrogenous waste in living conditions that include
A) lots of fresh water flowing across the gills of a fish.
B) lots of seawater, such as a bird living in a marine environment.
C) lots of seawater, such as a marine mammal (e.g., a polar bear).
D) a terrestrial environment, such as that supporting crickets.

Answer: A

Which nitrogenous waste has the greatest number of nitrogen atoms?
A) ammonia
B) ammonium ions
C) urea
D) uric acid

Answer: D

Which of the following animals generally has the lowest volume of urine production?
A) a vampire bat
B) a salmon in fresh water
C) a marine bony fish
D) a freshwater bony fish

Answer: C

Which of the following most accurately describes selective permeability?
A) An input of energy is required for transport.
B) There must be a concentration gradient for molecules to pass through a membrane.
C) Lipid-soluble molecules pass through a membrane.
D) Only certain molecules can cross a cell membrane.

Answer: D

Why are the renal artery and vein critical to the process of osmoregulation in vertebrates?
A) The renal artery and vein are the main pathways regulating how much is produced by the kidneys.
B) The kidneys require constant and abnormally high oxygen supply to function.
C) The kidneys require higher than normal levels of hormones.
D) The renal artery delivers blood with nitrogenous waste to the kidney and the renal vein brings blood with less nitrogenous wastes away from the kidneys.

Answer: D

Materials are returned to the blood from the filtrate by which of the following processes?
A) filtration
B) ultrafiltration
C) selective reabsorption
D) secretion

Answer: C

The osmoregulatory/excretory system of a freshwater flatworm is based on the operation of
A) protonephridia.
B) metanephridia.
C) Malpighian tubules.
D) nephrons.

Answer: A

A primary reason that the kidneys have one of the highest metabolic rates of all body organs is that
A) it stores the body's excess fats.
B) it has membranes of varying permeability to water.
C) it operates an extensive set of active-transport ion pumps.
D) it is the body's only means of shedding excess nutrients.

Answer: C

The loop of Henle dips into the renal cortex. This is an important feature of osmoregulation in terrestrial vertebrates because
A) differential permeabilities of ascending and descending limbs of the loop of Henle are important in establishing an osmotic gradient
B) additional filtration takes place along the loop of Henle
C) the loop of Henle plays an important role in detoxification
D) absorptive processes taking place in the loop of Henle are hormonally regulated

Answer: A

Natural selection should favor the highest proportion of juxtamedullary nephrons in which of the following species?
A) a river otter
B) a mouse species living in a tropical rain forest
C) a mouse species living in a temperate broadleaf forest
D) a mouse species living in a desert

Answer: D

Increased antidiuretic hormone (ADH) secretion is likely after
A) drinking lots of pure water.
B) sweating-induced dehydration increases plasma osmolarity.
C) ingestion of ethanol (drinking alcoholic drinks).
D) eating a small sugary snack.

Answer: B

After drinking alcoholic beverages, increased urine excretion is the result of
A) increased aldosterone production.
B) increased blood pressure.
C) inhibited secretion of antidiuretic hormone (ADH).
D) increased reabsorption of water in the proximal tubule.

Answer: C

Testosterone is an example of a chemical signal that affects the very cells that synthesize it, the neighboring cells in the testis, along with distant cells outside the gonads. Thus, testosterone is an example of
I) an autocrine signal.
II) a paracrine signal.
III) an endocrine signal.

A) only I and III
B) I, II, and III
C) only II and III
D) only I and II

Answer: B

Prostaglandins are local regulators whose chemical structure is derived from
A) fatty acids
B) amino acids
C) steroids
D) oligosaccharides

Answer: A

A cell with membrane-bound proteins that selectively bind a specific hormone is called that hormone's
A) secretory cell.
B) plasma cell.
C) endocrine cell.
D) target cell.

Answer: D

The reason that the steroid hormone aldosterone affects only a small number of cells in the body is that
A) only its target cells get exposed to aldosterone.
B) only its target cells contain aldosterone receptors.
C) it is unable to enter nontarget cells.
D) nontarget cells destroy aldosterone before it can produce any effect.

Answer: B

Different body cells can respond differently to the same peptide hormones because
A) different target cells have different sets of genes.
B) each cell converts that hormone to a different metabolite.
C) a target cell's response is determined by the components of its signal transduction pathways.
D) the circulatory system regulates responses to hormones by routing the hormones to specific targets.

Answer: C

The steroid hormone that coordinates molting in arthropods is
A) ecdysone.
B) glucagon.
C) thyroxine.
D) oxytocin.

Answer: A

Insect hormones and their receptors
A) act independently of each other.
B) are a focus in pest-control research.
C) utilize cell-surface receptors only.
D) are active independently of environmental cues.

Answer: B

What property of steroid hormones allows them to cross the phospholipid bilayer?
A) Steroid hormones can act in very small concentrations and very few molecules of steroids need to cross the lipid bilayer.
B) Steroid hormones are lipid soluble and easily cross the phospholipid bilayer.
C) Steroid hormones act on cells close to where they were produced and very few molecules are required to travel such a short distance to cross the lipid bilayer.
D) Steroid hormones act on the same cells in which they are produced and, therefore, are within the cell they are acting upon.

Answer: B

If a biochemist discovers a new molecule, which of the following pieces of data would allow her to draw the conclusion that the molecule is a steroid hormone?
I) The molecule is lipid soluble.
II) The molecule is derived form a series of steps beginning with cholesterol.
III) The molecule acts at a target tissue some distance from where it is produced.
IV) The molecule uses a carrier protein when in an aqueous solution such as blood.

A) only II and IV
B) only only I and III
C) only I, III, and IV
D) I, II, IIII, and IV

Answer: D

During mammalian labor and delivery, the contraction of uterine muscles is enhanced by oxytocin. This is an example of
A) a negative feedback system.
B) a hormone that acts in an antagonistic way with another hormone.
C) a hormone that is involved in a positive feedback loop.
D) signal transduction immediately changing gene expression in its target cells.

Answer: C

Which of the following has both endocrine and exocrine activity?
A) the pituitary gland
B) parathyroid glands
C) salivary glands
D) the pancreas

Answer: D

An example of antagonistic hormones controlling homeostasis is
A) thyroxine and parathyroid hormone in calcium balance.
B) insulin and glucagon in glucose metabolism.
C) progestins and estrogens in sexual differentiation.
D) epinephrine and norepinephrine in fight-or-flight responses.

Answer: B

Hormones secreted by the posterior pituitary gland are made in the ________.
A) thalamus
B) medulla oblongata
C) cerebellum
D) hypothalamus

Answer: D

In a lactating mammal, the two hormones that promote milk synthesis and milk release, respectively, are
A) prolactin and calcitonin.
B) prolactin and oxytocin.
C) follicle-stimulating hormone and luteinizing hormone.
D) luteinizing hormone and oxytocin.

Answer: B

Which of the following is the most likely explanation for hypothyroidism in a patient whose iodine level is normal?
A) greater production of T₃ than of T₄
B) hyposecretion of TSH
C) hypersecretion of TSH
D) hypersecretion of MSH

Answer: B

Fight-or-flight reactions include activation of
A) the parathyroid glands, leading to increased metabolic rate.
B) the thyroid gland, leading to an increase in the blood calcium concentration.
C) the anterior pituitary gland, leading to cessation of gonadal function.
D) the adrenal medulla, leading to increased secretion of epinephrine.

Answer: D

People with type II diabetes mellitus have defective insulin receptors that cannot respond to insulin properly. Relative to normal individuals, what would be the effect on blood glucose levels under conditions of chronic stress that kept blood cortisol levels high? There would be ________.
A) less increase in blood glucose levels in individuals with type II diabetes mellitus than in normal individuals.
B) less decrease in blood glucose levels in individuals with type II diabetes mellitus than in normal individuals.
C) a greater increase in blood glucose levels in individuals with type II diabetes mellitus than in normal individuals.
D) a greater decrease in blood glucose levels in individuals with type II diabetes mellitus than in normal individuals.

Answer: C

Asexual reproduction results in offspring that are genetically identical to their parent. What type of cell process occurs to generate this type of offspring?
A) meiosis
B) mitosis
C) cell fusion

Answer: B

What makes sexually reproduced offspring genetically different from their parents?
A) genetic recombination during mitosis
B) crossing over during mitosis
C) genetic recombination during mitosis
D) sexual reproduction does not produce genetically different offspring

Answer: A

Which of the following is most true of sexual reproduction?
A) Only half of the offspring from sexually reproducing females are also females.
B) Sexual reproduction is completed more rapidly than asexual reproduction.
C) Asexual reproduction is better suited to environments with extremely varying conditions.
D) Asexual reproduction produces offspring of greater genetic variety.

Answer: A

In an animal that switches between sexual and asexual reproduction, when is sexual reproduction more likely to occur?
A) when males and females find each other
B) when conditions for survival are favorable
C) when conditions for survival are unfavorable
D) what conditions favor sexual over asexual remains a complete mystery.

Answer: C

Animals that have external fertilization are most likely to reproduce in which of the following areas?
A) sand dune
B) tallgrass prairie
C) polar ice sheet
D) shallow lake

Answer: D

In humans, the follicular cells that remain behind in the ovary following ovulation become
A) the ovarian endometrium that is shed at the time of the menses.
B) a steroid-hormone synthesizing structure called the corpus luteum.
C) the thickened portion of the uterine wall.
D) swept into the fallopian tube.
E) the placenta, which secretes cervical mucus.

Answer: B

At the time of fertilization, the complete maturation of each oogonium has resulted in
A) one secondary oocyte.
B) two primary oocytes.
C) four secondary oocytes.
D) four primary oocytes.

Answer: A

Which of the following correctly describes a difference between spermatogenesis and oogenesis?
A) In spermatogenesis, mitosis occurs twice and meiosis once, while in oogenesis, mitosis occurs once and meiosis twice.
B) Spermatogenesis result sin four mature sperm cells, while oogenesis results in one mature egg cell. In spermatogenesis, mitosis occurs twice and meiosis once, while in oogenesis, mitosis occurs once and meiosis twice.
C) Spermatogenesis results in one mature sperm cell, while oogenesis results in four mature egg cells.
D) Spermatogenesis results in four mature sperm cells, while oogenesis results in one mature egg cell.

Answer: D

Mature human sperm and ova are similar in that
A) they both have the same number of chromosomes.
B) they are approximately the same size.
C) they each have a flagellum that provides motility.
D) they are produced from puberty until death.

Answer: A

Among mammals, the male and female genital structures that consist mostly of erectile tissue include the
A) penis and clitoris.
B) vas deferens and oviduct.
C) testes and ovaries.
D) seminiferous tubules and hymen.

Answer: A

Among human males, both semen and urine normally travel along the
A) vas deferens.
B) urinary bladder.
C) seminal vesicle.
D) urethra.

Answer: D

Human sperm cells first arise in the
A) prostate gland.
B) vas deferens.
C) seminiferous tubules.
D) epididymis.

Answer: C

A primary response by the Leydig cells in the testes to the presence of luteinizing hormone is an increase in the synthesis and secretion of
A) inhibin.
B) testosterone.
C) oxytocin.
D) prolactin.

Answer: B

In correct chronological order, the three phases of the human ovarian cycle are
A) menstrual → ovulation → luteal.
B) follicular → luteal → secretory.
C) menstrual → proliferative → secretory.
D) follicular → ovulation → luteal.

Answer: D

An ectopic pregnancy occurs when a fertilized egg implants somewhere other than in the lining of the uterus. Usually it implants in the oviduct. Which of the following would be the most likely explanation for such a pregnancy being unsuccessful?
A) The necessary hormones cannot reach the developing fetus in the oviduct.
B) The lining of the oviduct is unable to support the developing fetus.
C) Human chorionic gonadotropin (hCG) cannot be produced in the oviduct.
D) The orientation of the baby would be sideways.

Answer: B

In the above figure, which letter points to the prostate gland?
A) A
B) B
C) C
D) D

Answer: B

In the above figure, which letter points to the vas deferens?
A) A
B) B
C) C
D) D

Answer: D

(PARAGRAPH) Refer to the paragraph on the effects of estrogens in the environment. What is the significance of using the concentrations of 5, 25, and 100 ng/l of 17B-estradiol for the dose in this experiment?
A) These concentrations are effective, yet not lethal to the fish.
B) These concentrations are standard in toxicology assays.
C) These concentrations are similar to those found in many animals.
D) These concentrations are found in the environment.

Answer: D

(PARAGRAPH) Refer to the paragraph on the effects of estrogens in the environment. You are assigned to write the report to the Environmental Protection Agency, which needs to decide what level of 17B-estradiol to permit in sewage output. You do not want to make the level any lower than necessary, because it requires substantial additional money for the extra treatment of sewage. Given the data presented above, what level of 17B-estradiol would you suggest is safe to prevent feminization of fish?
A) 25 ng/l
B) 12.5 ng/l
C) 100 ng/l
D) 2.5 ng/l

Answer: A

In the above figure, which letter points to the corpus luteum?
A) A
B) B
C) C
D) D

Answer: D

In the above figure, which letter points to the cervix?
A) A
B) B
C) C
D) D

Answer: C