Bio Exam2 (43, 45, 46, 47, 48) [83%]

Which of the following pairs of proteins shares the most overall similarity in structure? A) B-cell receptors and T-cell antibodies B) B-cell receptors and antibodies C) T-cell receptors and antibodies D) antibodies and antigens

B-cell receptors and antibodies

Tadpoles must undergo a major metamorphosis to become frogs. This change includes reabsorption of the tail, growth of limbs, calcification of the skeleton, increase in rhodopsin in the eye, development of lungs, change in hemoglobin structure, and reformation of the gut from the long gut of an herbivore to the short gut of a carnivore. Amazingly, all of these changes are induced by thyroxine. What is the most likely explanation for such a wide array of effects of thyroxine? A) There are many different forms of thyroxine, each specific to a different tissue. B) Different tissues have thyroxine receptors that activate different signal transduction pathways. C) Some tissues have membrane receptors for thyroxine, while other tissues have thyroxine receptors within the nucleus. D) Different releasing hormones release thyroxine to different tissues.

Different tissues have thyroxine receptors that activate different signal transduction pathways.

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 from a series of steps beginning with cholesterol. III) The molecule acts as 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 I and III B) only II and IV C) only I, III, and IV D) I, II, III, and IV

I, II, III, and IV

Engulfing-phagocytic cells of innate immunity of vertebrates include _____. I) neutrophils II) macrophages III) dendritic cells IV) natural killer cells A) I and III B) II and IV C) I and IV D) I, II, and III

I, II, and III

Polypeptides can have which of the following types of effects? I) autocrine II) paracrine III) endocrine A) only I and III B) only II and III C) only I and II D) I, II, and III

I, II, and III

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

I, II, and III

Arrange in the correct sequence these components of the mammalian immune system as it first responds to a pathogen. I) Pathogen is destroyed. II) Lymphocytes secrete antibodies. III) Antigenic determinants from pathogen bind to antigen receptors on lymphocytes. IV) Lymphocytes specific to antigenic determinants from pathogen become numerous. V) Only memory cells remain. A) I -> III -> II -> IV -> V B) II -> I -> IV -> III -> V C) IV -> II -> III -> I -> V D) III -> IV -> II -> I -> V

III -> IV -> II -> I -> V

In a humoral or antibody-mediated immune response, specific B cells are stimulated by Helper T cells to transform into plasma cells that secrete antibodies. Which would be an important feature added to B cells in this transition process? A) Duplication of specific gene sequences for the appropriate antibody. B) Increased rough endoplasmic reticulum in order to have the surface area needed for antibody production. C) Duplication of lysosomes in order to store the antibodies before transport.

Increased rough endoplasmic reticulum in order to have the surface area needed for antibody production.

What major advantage is conveyed by having a system of adaptive immunity? A) It enables a rapid defense against an antigen that has been previously encountered. B) It enables an animal to counter most pathogens almost instantly the first time they are encountered. C) It results in effector cells with specificity for a large number of antigens. D) It allows for the destruction of antibodies.

It enables a rapid defense against an antigen that has been previously encountered

An immune response to tissue graft will differ from an immune response to bacterium because _____. A) MHC molecules of the donor may stimulate rejection of the graft tissue, but bacteria lack MHC molecules B) the tissue graft, unlike the bacterium, is isolated from the circulation and will not enter into an immune response C) a bacterium cannot escape the immune system by replicating inside normal body cells D) the graft will stimulate an autoimmune response in the recipient

MHC molecules of the donor may stimulate rejection of the graft tissue, but bacteria lack MHC molecules

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

One has a major role in antibody production, while the other has a major role in cytotoxicity.

What property of steroid hormones allows them to cross the phospholipid bilayer? A) Steroid hormones are lipid soluble and easily cross the phospholipid bilayer. B) Steroid hormones can act in very small concentrations and very few molecules of steroids need to cross the lipid 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.

Steroid hormones are lipid soluble and easily cross the phospholipid bilayer.

You are dissecting a fish in your biology laboratory section. Your teaching assistant points out a long oval structure and tells you it is an endocrine gland. Which of the following would you then know is a true statement about this structure? A) It secretes a product that is released through a series of ducts. B) The gland's product will only interact with receptors on the cell membrane. C) The gland's product is lipid soluble. D) The gland produces and secretes its product into the blood.

The gland produces and secretes its product into the blood.

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) Your friend had antibodies to that virus. B) You had an adaptive immunity to that virus. C) Your friend had an autoimmune disorder. D) Your friend had allergies.

You had an adaptive immunity to that virus.

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 the adaptive immune system fails to recognize the second infection by the same antigen C) a condition in which self molecules are treated as non-self D) a condition in which the immune system creates random antibodies without being triggered by an antigen

a condition in which self molecules are treated as non-self

The complement system is _____. A) a set of proteins involved in innate but not acquired immunity B) a group of proteins that includes interferons and interleukins C) a group of antimicrobial proteins that act together in a cascade fashion D) a set of proteins that act individually to attack and lyse microbes

a group of antimicrobial proteins that act together in a cascade fashion

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

a hormone that is involved in a positive feedback loop

Different body cells can respond differently to the same peptide hormones because _____. A) different target cells have different sets of genes B) a target cell's response is determined by the components of its signal transduction pathways C) the circulatory system regulates responses to hormones by routing the hormones to specific targets D) the hormone is chemically altered in different ways as it travels through the circulatory system

a target cell's response is determined by the components of its signal transduction pathways

Bacteria entering the body through a small cut in the skin _____. A) inactivate the erythrocytes B) stimulate apoptosis of nearby body cells C) stimulate release of interferons D) activate a group of proteins called complement

activate a group of proteins called complement

Mutant fruit flies that make only one antimicrobial peptide were tested for survival after infection with Neurospora crassa fungi or with Micrococcus luteus bacteria. [IMAGE (2)] The results shown in the graphs support the hypothesis that _____. A) adding the defensin gene to such mutants protects them from death by fungal infection B) adding the dryomycin gene to such mutants protects them from death by fungal infection C) wild-type flies with the full set of genes for antimicrobial peptides are highly susceptible to these infective agents D) the presence of any single antimicrobial peptide protects against both infective agents

adding the drosomycin gene to such mutants protects them from death by fungal infection

Clonal selection is an explanation for how _____. A) V, J, and C gene segments are rearranged B) an antigen can provoke production of high levels of specific antibodies C) HIV (human immunodeficiency virus) can disrupt the immune system D) macrophages can recognize specific T cells and B cells

an antigen can provoke production of high levels of specific antibodies

The relationship between the insect hormones ecdysteroid and PTTH is an example of _____. A) an interaction of the endocrine and nervous systems B) competitive inhibition of a hormone receptor C) how peptide-derived hormones have more widespread effects than steroid hormones D) homeostasis maintained by antagonistic hormones

an interaction of the endocrine and nervous systems

A patient who has a high level of mast cell activity, dilation of blood vessels, and acute drop in blood pressure is likely suffering from _____. A) an autoimmune disease B) a typical skin allergy (contact dermatitis) that can be treated by antihistamines C) an organ transplant, such as a skin graft D) anaphylactic shock immediately following exposure to an allergen

anaphylactic shock immediately following exposure to an allergen

A patient complaining of watery, itchy eyes and sneezing after being given a flower bouquet as a birthday gift should first be treated with _____. A) a vaccine B) sterile pollen C) antihistamines D) monoclonal antibodies

antihistamines

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

antimicrobial peptides

Hormone X activates the cAMP second messenger system in its target cells. The greatest response by a cell would come from _____. A) applying a molecule of hormone X to the extracellular fluid surrounding the cell B) injecting a molecule of hormone X into the cytoplasm of the cell C) applying a molecule of cAMP to the extracellular fluid surrounding the cell D) injecting a molecule of activated, cAMP-dependent protein kinase into the cytoplasm of the cell

applying a molecule of hormone X to the extracellular fluid surrounding the cell

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 environment cues

are a focus in pest control research

A newborn who is accidentally given a drug that destroys the thymus would most likely _____. A) lack innate immunity B) be unable to genetically rearrange antigen receptors C) be unable to differentiate and mature T cells D) have a reduced number of B cells and be unable to form antibodies

be unable to differentiate and mature T cells

Growth factors are local regulators that _____. A) are modified fatty acids that stimulate bone and cartilage growth B) are found on the surface of cancer cells and stimulate abnormal cell division C) bind to cell-surface receptors and stimulate growth and development of target cells D) convey messages between nerve cells

bind to cell-surface receptors and stimulate growth and development of target cells

Which of the following would prevent allergic attacks? A) blocking the attachment of the IgE antibodies to the mast cells B) blocking the antigenic determinants of the IgM antibodies C) reducing the number of helper T cells in the body D) reducing the number of cytotoxic cells

blocking the attachment of the IgE antibodies to the mast cells

Select the pathway that would lead to the activation of cytotoxic T cells. A) B cell contact antigen -> helper T cell is activated -> clonal selection occurs B) body cell becomes infected with a virus -> new viral proteins appear -> class I MHC molecule-antigen complex displayed on cell surface C) complement is secreted -> B cell contacts antigen -> helper T cell activated -> cytokines released D) cytotoxic T cells -> class II MHC molecule-antigen complex displayed -> cytokines released -> cell lysis

body cell becomes infected with a virus -> new viral proteins appear -> class I MHC molecule-antigen complex displayed on cell surface

When adenylyl cyclase is activated _____. A) cAMP is created B) cAMP is destroyed C) G proteins bind to cAMP D) steroid hormones pass through the lipid bilayer

cAMP is created

Septic shock, a systemic response including high fever and low blood pressure, is a response to _____. A) certain bacterial infections B) specific forms of viruses C) the presence of natural killer cells D) increased production of neutrophils

certain bacterial infections

The EBV antigen fragments will be presented by the virus-infected cells along with _____. A) a complement B) antibodies C) class I MHC molecules D) class II MHC molecules

class I MHC molecules

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

complement protein

An otherwise healthy student in your class is infected with EBV, the virus that causes infectious mononucleosis. The same student had already been infected when she was a child, at which time she had merely experienced a mild sore throat and swollen lymph nodes in her neck. This time, though infected, she does not get sick. Her immune system's recognition of the second infection involves memory _____. A) helper T cells B) natural killer cells C) plasma cells D) cytotoxic T cells

cytotoxic T cells

T cells of the immune system include _____. A) CD4, CD8, and plasma cells B) cytotoxic and helper cells C) plasma, antigen-presenting and memory cells D) lymphocytes, macrophages, and dendritic cells

cytotoxic and helper cells

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

double-stranded RNA

The number of major histocompatibility (MHC) protein combinations possible in a given population is enormous. However, an individual in that diverse population has a far more limited array of MHC molecules because _____. A) the MHC proteins are made from several different gene regions that are capable of rearranging in a number of ways B) MHC proteins from one individual can only be of class I or class II C) each of the MHC genes has a large number of alleles, but each individual only inherits two for each gene D) once a B cell has matured in the bone marrow, it is limited to two MHC response categories

each of the MHC genes has a large number of alleles, but each individual only inherits two for each gene

The steroid hormone that coordinates molting in arthropods is _____. A) ecdysteroid B) glucagon C) thyroxine D) growth hormone

ecdysteroid

If a portion of the pancreas is surgically removed from a rat and the rat subsequently loses its appetite, one explanation is that the removed portion contains cells that secrete a chemical signal that somehow stimulates appetite. Given this scenario, what type of chemical signaling is occurring? A) autocrine B) paracrine C) endocrine D) neuroendocrine

endocrine

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 major histocompatibility (MHC) proteins may not 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 MHC class II genes are not expressed in bone marrow

even though Jane's blood type is a match to Bob's, her major histocompatibility (MHC) proteins may not be a match

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

fatty acids

Analysis of a blood sample from a fasting individual who had not eaten for twenty-four hours would be expected to reveal high levels of _____. A) insulin B) glucagon C) gastrin D) glucose

glucagon

B cells interacting with helper T cells are stimulated to differentiate when _____. A) B cells produce IgE antibodies B) B cells release cytokines C) cytotoxic T cells present the class II MHC molecule-antigen complex on their surface D) helper T cells release cytokines

helper T cells release cytokines

The ability of some viruses to remain inactive (latent) for a period of time is exemplified by _____. A) influenza, a particular strain of which returns every 10-20 years B) herpes simplex viruses (oral or genital) whose reproduction is triggered by physiological or emotional stress in the host C) Kaposi's sarcoma, which causes a skin cancer in people with AIDS but rarely in those not infected by HIV D) the virus that causes a form of the common cold, which recurs in patients many times in their lives

herpes simplex viruses (oral or genital) whose reproduction is triggered by physiological or emotional stress in the host

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

hypothalamus

Portal blood vessels connect two capillary beds found in the _____. A) hypothalamus and thalamus B) anterior pituitary and posterior pituitary C) hypothalamus and anterior pituitary D) posterior pituitary and thyroid gland

hypothalamus and anterior pituitary

Inflammatory responses typically include _____. A) increased activity of phagocytes in an inflamed area B) reduced permeability of blood vessels to conserve plasma C) release of substances to decrease the blood supply to an inflamed area D) inhibiting the release of white blood cells from bone marrow

increased activity of phagocytes in an inflamed area

A boy falls while riding his bike. A scrape on his hand almost immediately begins to bleed and becomes red, warm, and swollen. What response is occurring? A) inflammatory response B) lytic response C) adaptive immune response D) autoimmune response

inflammatory response

Aspirin and ibuprofen both _____. A) inhibit the synthesis of prostaglandins B) inhibit the release of nitric oxide, a potent vasodilator C) activate the paracrine signaling pathways that form blood clots D) stimulate vasoconstriction in the kidneys

inhibit the synthesis of prostaglandins

An individual who has been bitten by a poisonous snake that has a fast-acting toxin would likely benefit from _____. A) vaccination with a weakened form of the toxin B) injection of antibodies to the toxin C) injection of interleukin-1 D) injection of interferon

injection of antibodies to the toxin

Acidity in human sweat is an example of _____. A) cell-mediated immune responses B) acquired immunity C) adaptive immunity D) innate immunity

innate immunity

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

insulin and glucagon in glucose metabolism

A nonfunctional CD4 protein on a helper T cell would result in the helper T cell being unable to _____. A) respond to T-independent antigens B) lyse tumor cells C) stimulate a cytotoxic T cell D) interact with a class II MHC-antigen complex

interact with a class II MHC-antigen complex

Innate immunity _____. A) is activated immediately upon infection B) depends on an infected animal's previous exposure to the same pathogen C) is based on recognition of antigens that are specific to different pathogens D) is found only in vertebrate animals

is activated immediately upon infection

If a person loses a large amount of water in a short period of time, he or she may die from dehydration. Antidiuretic hormone (ADH) can help reduce water loss through its interaction with its target cells in the _____. A) anterior pituitary B) posterior pituitary C) bladder D) kidney

kidney

Vaccination increases the number of _____. A) lymphocytes with receptors that can bind to the pathogen B) epitopes that the immune system can recognize C) macrophages specific for a pathogen D) major histocompatibility (MHC) molecules that can present an antigen

lymphocytes with receptors that can bind to the pathogen

The cells and signaling molecules involved in the initial stages of the inflammatory response are _____. A) phagocytes and chemokines B) dendritic cells and interferons C) mast cells and histamines D) lymphocytes and interferons

mast cells and histamines

A product of the anterior pituitary gland that causes color changes in its target cells is _____. A) follicle-stimulating hormone (FSH) B) luteinizing hormone (LH) C) thyroid-stimulating hormone (TSH) D) melanocyte-stimulating hormone (MSH)

melanocyte-stimulating hormone (MSH)

If a patient is missing B and T cells, what would be absent from the immune response? A) memory B) lysozymes C) cytokines D) defense against bacteria

memory

A certain cell type has existed in the blood and tissue of its vertebrate host's immune system for over twenty years. One day, it recognizes a newly arrived antigen and binds to it, subsequently triggering a secondary immune response in the body. Which of the following cell types most accurately describes this cell? A) plasma cell B) thyroid cell C) memory cell D) macrophage

memory cell

CD4 and CD8 are _____. A) proteins secreted by antigen-presenting cells B) receptors present on the surface of natural killer cells C) molecules present on the surface of T cells where they interact with major histocompatibility (MHC) molecules D) molecules on the surface of antigen-presenting cells where they enhance B cell activity

molecules present on the surface of T cells where they interact with major histocompatibility (MHC) molecules

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) macrophages D) B cells

natural killer cells

The interrelationships between the endocrine and the nervous systems are especially apparent in a _____. A) steroid-producing cell in the adrenal cortex B) neurosecretory cell in the hypothalamus C) brain cell in the cerebral cortex D) cell in the pancreas that produces digestive enzymes

neurosecretory cell in the hypothalamus

An immunoglobin (lg) 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) one H region and one L region C) three H regions and one L region D) two C regions and two V regions

one C region and one V region

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

only I and II

Which of the following statements are correct? I) Hormones often regulate homeostasis through antagonistic functions. II) Hormones of the same chemical class usually have the same functions. III) Hormones are secreted by specialized cells usually located in exocrine glands. IV) Hormones are often regulated through feedback loops. A) only II and III B) only I and III C) only III and IV D) only I and IV

only I and IV

Which of the following statements about epitopes are correct? I) B-cell receptors bind to epitopes. II) T-cell receptors bind to epitopes III) There can be 10 or more different epitopes on each antigen. IV) There is a one-to-one correspondence between antigen and epitope. A) only I and III B) only II and IV C) only I, II, and III D) only II, III, and IV

only I, II, and III

Which of the following statements are fundamental to the clonal-selection theory of how the adaptive immune system functions? I) Each lymphocyte has a unique membrane receptor that recognizes one antigen. II) When the lymphocyte bind an antigen, it is activated and begins dividing to form many identical copies of itself. III) Cloned lymphocytes have slight differences and are selected by the spleen for removal if they do not bind an antigen. IV) Cloned cells descend from an activated lymphocyte and persist even after the pathogen is eliminated. A) only I and III B) only II and IV C) only I, II, and IV D) only II, III, and IV

only I, II, and IV

Which of the following would help a virus avoid triggering an effective adaptive immune response? I) having frequent mutations in genes for surface proteins II) building the viral shell from host proteins III) producing proteins very similar to those of other viruses IV) infecting and killing helper T cells A) only I and III B) only I, II, and IV C) only I, II, and III D) only II, III, and IV

only I, II, and IV

Lymphocytes mature in the _____. I) spleen II) thymus III) bone marrow A) only I and III B) only I and II C) only II and III D) I, II, and III

only II and III

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

only its target cells contain aldosterone receptors

A cluster of tumor cells that produces and secretes growth factors to induce surrounding cells to grow and divide is showing which type of cell-to-cell signaling? A) autocrine B) paracrine C) endocrine D) neuroendocrine

paracrine

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

passive immunity

What is the only type of chemical signal that does not alter the physiology of the animal producing that signal? A) neural B) paracrine C) neuroendocrine D) pheromones

pheromones

Mucus occurs in both the respiratory and digestive tracts. What is its main immunological function? A) sweeping away debris B) physically trapping pathogens C) destruction of pathogens because it is acidic D) increasing oxygen absorption

physically trapping pathogens

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

placental transfer of antibodies

Which of the following is crucial to activation of the adaptive immune response? A) memory cells B) presentation of MHC (major histocompatibility complex)-antigen complex on a cell surface C) somatic hypermutation D) phagocytosis of antibody-antigen complex by macrophages in the blood (the humoral response)

presentation of MHC (major histocompatibility complex)-antigen complex on a cell surface

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

prolactin and oxytocin

Based on their effects, which pair below would NOT be expected to be active at the same time and place? A) prostaglandin and nitric oxide B) endocrine and exocrine glands C) hormones and target cells D) neurosecretory cells and neurotransmitters

prostaglandin and nitric oxide

Yearly vaccination of humans for influenza viruses is necessary because _____. A) of an increase in immunodeficiency diseases B) the flue can generate anaphylactic shock C) surviving the flu one year exhausts the immune system to nonresponsiveness the second year D) rapid mutation in flu viruses alter the surface proteins in infected host cells

rapid mutation in flue viruses alters the surface proteins in infected host cells

Within a differentiated B cell, the rearrangement of DNA sequences between variable regions and joining regions is accomplished by a(n) _____. A) RNA polymerase B) reverse transcriptase C) epitopase D) recombinase

recombinase

Injury localized to the hypothalamus would most likely disrupt _____. A) short-term memory B) coordination during locomotion C) executive functions, such as decision making D) regulation of body temperature

regulation of body temperature

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

short-lived plasma cells that secrete antibodies for the antigen

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

target cell

Which of the following are similar in structure to cholesterol? A) leptin and serotonin B) luteinizing hormone and insulin C) melanocyte-stimulating hormone and vasopressin D) testosterone, estradiol, and cortisol

testosterone, estradiol, and cortisol

Immunological memory accounts for _____. A) the human body's ability to distinguish self from non-self B) the observation that some strains of the pathogen that causes dengue fever cause more sever disease than others C) the ability of a helper T cell to signal B cells via cytokines D) the ancient observation that someone who had recovered from the plague could safely care for those newly diseased

the ancient observation that someone who had recovered from the plague could safely care for those newly diseased

When antibodies bind antigens, the clumping of antigens results from _____. A) the antibody having at least two binding regions B) disulfide bridges between the antigens C) bonds between class I and class II MHC molecules D) denaturation of the antibodies

the antibody having at least two binding regions

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

the pancreas

The switch of one B cell from producing one class of antibody to another class of antibody that is responsive to the same antigen is due to _____. A) the rearrangement of V region genes in the clone of responsive B cells B) a switch in the kind of antigen-presenting cell that is involved in the immune response C) a patient's reaction to the first kind of antibody made by the plasma cells D) the rearrangement of immunoglobulin heavy-chain C region DNA

the rearrangement of immunoglobulin heavy-chain C region DNA

The eyes and the respiratory tract are both protected against infections by _____. A) interferons produced by immune cells B) the secretion of complement proteins C) the release of slightly alkaline secretions D) the secretion of lysozyme onto their surfaces

the secretion of lysozyme onto their surfaces

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

the set of major histocompatibility (MHC) molecules produced

When the beta cells of the pancreas release insulin into the blood, _____. A) the skeletal muscles and the adipose cells take up glucose at a faster rate B) the liver catabolizes glycogen C) the alpha cells of the pancreas release glucose into the blood D) the kidneys begin gluconeogenesis

the skeletal muscles and the adipose cells take up glucose at a faster rate

When a steroid hormone and a peptide hormone exert similar effects on a population of target cells, then _____. A) the steroid and peptide hormones must use the same biochemical mechanisms B) the steroid and peptide hormones must bind to the same receptor protein C) the steroid hormones affect the synthesis of effector proteins, whereas peptide hormones activate effector proteins already present in the cell D) the steroid hormones affect the activity of certain proteins within the cell, whereas peptide hormones directly affect the processing of mRNA

the steroid hormones affect the synthesis of effector proteins, whereas peptide hormones activate effector proteins already present in the cell

For the successful development of a vaccine to be used against a pathogen, it is necessary that _____. A) the surface antigens of the pathogen stay the same B) all of the surface antigens on the pathogen be identified C) the pathogen has only one epitope D) the major histocompatibility (MHC) molecules are heterozygous

the surface antigens of the pathogen stay the same

Steroid and peptide hormones typically have in common _____. A) the building blocks from which they are synthesized B) their solubility in cell membranes C) their requirement for travel through the bloodstream D) their reliance on signal transduction in the cell

their requirement for travel through the bloodstream

Jenner's successful use of cowpox virus as a vaccine against the smallpox virus was due to the fact that _____. A) the immune system responds nonspecifically to antigens B) the cowpox virus made antibodies in response to the presence of smallpox C) there are some epitopes (antigenic determinants) common to both pox viruses D) cowpox and smallpox are caused by the same virus

there are some epitopes (antigenic determinants) common to both pox viruses

In experiments where researchers suspect that a hormone may be responsible for a certain physiological effect, they may cut the neurons leading to the organ where the effect being studied occurs. What is the purpose of cutting these neurons? A) to make sure that the effect is not occurring through actions in the nervous system B) to make sure that the organ being affected cannot function unless the researchers stimulate it with an external electrical probe C) to impair the normal functions of the organ so that the hormonal effect can be more easily studied D) to numb the organ so that it can be probed without inducing pain in the lab animal

to make sure that the effect is not occurring through actions in the nervous system