Biology Chapter 43 and 44 Mastering Biology

Which of the following statements is not true?

A lymphocyte has receptors for multiple different antigens.

Antidiuretic hormone (ADH) and the renin-angiotensin-aldosterone system (RAAS) work together in maintaining osmoregulatory homeostasis through which of the following ways?

ADH regulates the osmolarity of the blood by altering renal reabsorption of water, and the RAAS maintains the osmolarity of the blood by stimulating both Na+ and water reabsorption.

How does an antihistamine reduce allergy symptoms?

An antihistamine blocks receptors for inflammatory chemicals released from granules within mast cells.

Examine the figure of a human nephron. Where and when does osmolarity of the filtrate increase?

As the filtrate moves down the descending limb of the loop of Henle

Selective secretion of toxins and drugs takes place in the structure labeled ________.

B

Each person makes more than 1 million different B cell antigen receptors and more than 10 million different T cell antigen receptors. How is such diversity in antigen receptors generated?

By combining variable elements, the immune system assembles many different receptors from a much smaller collection of parts.

What is the role of recombinase in generating lymphocyte diversity?

Early in B cell development, recombinase links one light-chain V gene segment to one J gene segment.

Vertebrate immune cells, which are phagocytic, include ________. I) neutrophils II) macrophages III) dendritic cells IV) natural killer cells

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) Antigens from a pathogen bind to antigen receptors on lymphocytes. IV) Lymphocytes specific to antigens from a pathogen become numerous. V) Only memory cells remain.

III → IV → II → I → V

What major advantage is conveyed by having a system of adaptive immunity?

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

Tissues are immunogically "typed" before an organ transplant to make sure that the donor and recipient match as closely as possible in their _____.

MHC (major histocompatibility complex) proteins

An immune response to a tissue graft will differ from an immune response to a bacterium because _____.

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

Use the following information to answer the question(s) below. An otherwise healthy student in your class was infected with EBV (the virus that causes infectious mononucleosis) when she was a child, at which time she had merely experienced a mild sore throat and swollen lymph nodes in her neck. When she is exposed to EBV again later in life, she does not get sick or have any symptoms of mononucleosis. Which of the following statements explains why your class mate does not exhibit symptoms of EBV infection?

Memory T cells quickly recognized the virus upon the second exposure and destroyed the virally infected cells.

Studies of cricket Malpighian tubules revealed that potassium ions accumulated inside the tubule, moving against the potassium concentration gradient. Based on the information, what can you infer about the mechanism of potassium transport?

Movement of potassium into the lumen of the Malpighian tubules is an energy-requiring process.

________ are cells of the mammalian innate immune response that help destroy tumors.

Natural killer cells

African lungfish, which are often found in small stagnant pools of fresh water, produce urea as a nitrogenous waste. What is the advantage of this adaptation?

Small stagnant pools do not provide enough water to dilute the toxic ammonia.

Select the correct statement describing the osmolarity of mammalian urine.

The osmolarity of mammalian urine may vary over time.

Studies of cricket Malpighian tubules revealed that potassium ions accumulated inside the tubule, moving against the potassium concentration gradient. How would you expect the movement of water to be influenced by the distribution of potassium ions?

There would be a net movement of water into the lumen of the tubules.

What role do transport epithelia play in osmoregulation of marine fish with bony skeletons?

They are involved in excretion of excess salt.

Which of the following is a general property of epithelial cells?

They display an apical and a basal surface that define cell polarity.

If you are hiking through the desert for several days, one would pack which of the following to ensure proper hydration?

a drink with a combination of water and electrolytes

In which of the following species should natural selection favor the highest proportion of juxtamedullary nephrons?

a mouse species living in a desert

Natural selection should favor the highest proportion of juxtamedullary nephrons in which of the following species?

a mouse species living in a desert

Aldosterone is _____.

a steroid hormone that reduces the amount of fluid excreted in the urine

Which of these is not part of insect immunity?

activation of natural killer cells

The results shown in the graphs support the hypothesis that ________.

adding the defensin gene to such mutants protects them from death by bacterial infection

Freshwater fish excrete nitrogenous wastes as _____.

ammonia

A patient complaining of watery, itchy eyes and sneezing after being given a flower bouquet as a birthday gift should first be treated with _____.

antihistamines

The role of active cytotoxic T cells is to attack _____.

body cells that have been infected

Which of the following are similarities between B cells and T cells? I) They both recognize antigen using immunoglobulin receptors. II) Both B cells and T cells undergo clonal selection after encountering an antigen. III) B cells and T cells both maintain an immunological memory of previously encountered antigens

both II and III

Helper T cells are part of _____.

cell-mediated immune responses

Innate immunity and acquired immunity are both _____.

characteristics of all vertebrate animals

The structural component(s) of the mammalian nephron where the transcytosis of water increases due to the action of anti-diuretic hormone is/are the _____.

collecting duct

Which of the following components of the immune system destroys bacteria by punching holes in the wall of the bacteria?

complement protein

T cells of the immune system include _____.

cytotoxic and helper cells

The loop of Henle dips into the renal cortex. This is an important feature of osmoregulation in terrestrial vertebrates because _____.

differential permeabilities of ascending and descending limbs of the loop of Henle are important in establishing an osmotic gradient

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 ________.

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

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 ________.

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

Nitrogen is absent from

fatty acids

Which process in the nephron is least selective?

filtration

Choose a pair that correctly associates the mechanism for osmoregulation or nitrogen removal with the appropriate animal.

flame bulb: flat worm

In osmosis, water undergoes net diffusion to an area of lower

free water concentration

Excessive formation of uric acid crystals in humans leads to _____.

gout, a painful inflammatory disease that primarily affects the joints

In humans, the transport epithelial cells in the ascending loop of Henle _____.

have plasma membranes of low permeability to water

B cells interacting with helper T cells are stimulated to differentiate when _____.

helper T cells release cytokines

The ability of some viruses to remain inactive (latent) for a period of time is exemplified by _____.

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

In which of the labeled structures does passive water reabsorption take place?

in B, C, and E

If ATP production in a human kidney was suddenly halted, urine production would _____.

increase, and the urine would be isosmotic compared to plasma

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?

inflammatory response

Acidity in human sweat is an example of _____.

innate immunity

Excretory organs known as Malpighian tubules are present in _____.

insects

A nonfunctional CD4 protein on a helper T cell would result in the helper T cell being unable to ________.

interact with a class II MHC-antigen complex

Innate immunity ________.

is the first, and most general, mechanism of protection against pathogens

Compared to the seawater around them, most marine invertebrates are ________.

isoosmotic

The body fluids of an osmoconformer would be ________ with its ________ environment

isoosmotic; seawater

Among the following choices, the most concentrated urine is excreted by _____.

kangaroo rats

An excretory system that is partly based on the filtration of fluid under high hydrostatic pressure is the _____.

kidneys of vertebrates

Part complete Macrophages are _____.

large, phagocytic cells that can leave the circulation and enter the tissues of the body

Which of the following is characteristic of juxtamedullary nephrons?

long loop of Henle

Ammonia is likely to be the primary nitrogenous waste in living conditions that include _____.

lots of fresh water flowing across the gills of a fish

Processing of filtrate in the proximal and distal tubules _____.

maintains homeostasis of pH in body fluids

________ is a characteristic of adaptive immunity but not innate immunity.

memory

A certain cell type has existed in the blood and tissue of its vertebrate host's immune system for over 20 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?

memory cell

A primary reason for needing a new vaccine for influenza each year is that _____.

mutation in the influenza virus is frequent

An immunoglobulin (Ig) molecule, of any class, with regions symbolized as C or V, H or L, has a light chain made up of ________.

one C region and one V region

Animals have adapted different mechanisms for excreting nitrogenous waste products. Which of the following are selective pressures that likely influence which mechanism an animal uses? I) the amount of water available in the animal's habitat II) the energy needs of the animal III) the temperature of the animal's environment

only I and II

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.

only I, II, and III

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

only I, II, and IV

Which of the following proteins can be classified as immunoglobulins? I) T cell receptors II) B cell receptors III) Antigens

only II

Terrestrial animals are _____.

osmoregulators that must obtain water from the environment

What type of immunity is associated with breast feeding?

passive immunity

Mucus occurs in both the respiratory and digestive tracts. What is its main immunological function?

physically trapping of pathogens

Which of the following is the least likely substance to be found in the glomerular filtrate?

plasma proteins

Which of the following would not help a virus avoid triggering an adaptive immune response?

producing proteins very similar to those of other viruses

Materials are returned to the blood from the filtrate by which of the following processes?

reabsorption

Unlike an earthworm's metanephridia, a mammalian nephron

receives filtrate from blood instead of coelomic fluid.

Within a differentiated B cell, the rearrangement of DNA sequences between variable regions and joining regions is accomplished by a(n)_____.

recombinase

The fact that there are about a million different antigen receptors possible in human B cells is based on _____.

recombination of the segments of the receptor DNA that make up the functional receptor genes of differentiated B cells

The tertiary structure of a protein

relies on multiple weak bonds between side chains.

After blood flow is artificially reduced at one kidney, you would expect that kidney to secrete more of the hormone known as _____.

renin

Birds secrete uric acid as their nitrogenous waste because uric acid _____.

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

A bacterium or other particle taken up by phagocytosis is

routed to lysosomes for degradation

The osmoregulatory process called secretion refers to the _____.

selective elimination of excess ions and toxins from body fluids

Clonal selection and differentiation of B cells activated by antigen exposure leads to the production of _____.

short-lived plasma cells that secrete antibodies for the antigen

The genetic material of HIV consists of _____.

single-stranded RNA

If a person is prone to allergies, what treatment could redirect their immune response to help prevent future allergic reactions?

stimulating activated B cells to switch antibody production from class IgE to class IgM

Immunological memory accounts for _____.

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

The force driving simple diffusion is _____, while the energy source for active transport is _____.

the concentration gradient; ATP

An appropriate group of animals to examine to observe a Malpighian tubule would be _____.

the insects

Urea is _____.

the primary nitrogenous waste product of humans

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 _____.

the rearrangement of immunoglobulin heavy-chain C region DNA

The eyes and the respiratory tract are both protected against infections by _____.

the secretion of lysozyme onto their surfaces

Within a normally functioning kidney, blood can be found in _____.

the vasa recta

Jenner's successful use of cowpox virus as a vaccine against the smallpox virus was due to the fact that _____.

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

A primary reason that the kidneys have one of the highest metabolic rates of all body organs is that _____.

they operate an extensive set of active-transport ion pumps

Unlike most bony fishes, sharks maintain body fluids that are isoosmotic to seawater, so they are considered by many to be osmoconformers. Nonetheless, these sharks osmoregulate at least partially by _____.

tolerating high urea concentrations that are balanced with internal salt concentrations to seawater osmolarity

Vaccination offers protection against future exposure to pathogens because it ________.

triggers clonal expansion of lymphocytes

Which nitrogenous waste has the greatest number of nitrogen atoms?

uric acid

As a result of the non-selectivity of the kidney's filtration of small molecules, _____.

useful substances must be selectively reabsorbed

An epitope associates with which part of an antigen receptor or antibody?

variable regions of a heavy chain and light chain combined