BIO102 Final Exam

Single-celled Paramecium live in pond water (a hypotonic environment relative to the cytosol). They have a structural feature, a contractile vacuole, which enables them to osmoregulate. If sucrose or saline was added to the pond water in different concentrations (in millimolars, mM), under which conditions would you expect the contractile vacuole to be most active?

0.0 mM sucrose

Which of the following statements is not true?

A lymphocyte has receptors for multiple different antigens.

Which of the following cancer patients is likely to fair the best after being treated with checkpoint inhibitors?

A patient with a tumor that PRODUCES PD-L1.

Which of the following is true?

A person vaccinated for measles can get the disease, though it is not likely.

How does an antihistamine reduce allergy symptoms?

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

Which secretion is not a barrier that prevents pathogens from entering the body?

Antigens

Clonal selection is the division of _____ that have been stimulated by binding to an antigen, which results in the production of cloned _____.

B cells ... plasma cells and memory cells

The words "antigen" and "virus" are interchangeable.

False

True or false? The leukocytes of the innate immune system are B cells, macrophages, and neutrophils

False

A man who has been exposed to the flu virus is tested by his physician. The physician notes that the virus is present but no measurable level of antibodies corresponding to the virus are detected in his body. What does this mean?

He was probably exposed a few days ago and clonal selection has yet to produce plasma cells.

interact with the antigen-class II MHC complex presented by macrophages.

Helper T cells

What is the source of a viral envelope?

Host cell membrane -The viral envelope is derived from host cell membrane

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

How do cells involved in the innate immune response detect the presence of pathogens?

Leukocytes recognize unique molecules on pathogens.

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

Which of the following cells can engulf a pathogen?

Macrophages

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

Memory

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

Natural killer cells

Select the correct statement about osmolarity.

Osmolarity measures the moles of solute per liter of solution.

Which of the following events occurs first when a wound that breaks the skin has occurred?

Platelets release proteins that form clots and decrease bleeding

Birds, insects, and many reptiles excrete nitrogenous waste in the form of uric acid, which ______.

REDUCES water LOSS compared to other nitrogenous wastes, but requires MORE metabolic energy to produce

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.

You have a child and decide to not have him vaccinated. Who is most likely to support you in this decision?

The National Vaccine Information Center.

You just received a freshwater aquarium as a gift and decide to add more fish. When you get to the pet store, you find that the most beautiful fish are saltwater animals, but you decide to buy them anyway. What will happen when you put your expensive saltwater fish in your freshwater aquarium?

The cells of the fish will take up too much water, and the fish will die.

Select the correct statement describing the osmolarity of mammalian urine.

The osmolarity of mammalian urine may vary over time.

Salmon eggs hatch in fresh water. The fish then migrate to the ocean (a hypertonic solution) and, after several years of feeding and growing, return to fresh water to breed. How can these organisms make the transition from fresh water to ocean water and back to fresh water?

The salt transport mechanisms of the gill epithelia change during migration.

You are a molecular pathologist and have been asked to look at the tumor from a lung cancer patient. Which of the following is most likely?

There were more than fifty DNA mutations in the tumor.

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 is a true statement about memory cells?

They have a longer lifespan than plasma cells.

Which of the following statements best describes the role of mast cells in the inflammatory response?

They release chemicals that dilate blood vessels near the wound site, allowing blood components to enter the region from the bloodstream.

________ are receptor molecules on mammalian cells that recognize macromolecules that are present in or on certain groups of pathogens.

Toll-like receptors

What is the difference between a countercurrent multiplier system, such as the one involving the loop of Henle, and the countercurrent systems that maximize oxygen absorption by fish gills or reduce heat loss in endotherms?

Unlike the other countercurrent systems, a countercurrent multiplier system, such as the one involving the loop of Henle, expends energy in active transport.

Which of the following is the best definition of autoimmune disease?

a condition in which self molecules are treated as nonself (loss of self-tolerance)

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

a mouse species living in a desert

Aldosterone is _____.

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

Bacteria entering the body through a small cut in the skin _____.

activate a group of proteins called complement

Which of these is not part of insect immunity?

activation of natural killer cells

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 _____.

anaphylactic shock immediately following exposure to an allergen

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

body cells that have been infected

What is the function of reverse transcriptase?

catalyzing the formation of DNA from a RNA template

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

You are an oncologist. Six members of a family test positive for Lynch syndrome. Which of the following types of cancer are they most likely to get?

colorectal

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

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

Which process in the nephron is LEAST selective?

filtration

Low selectivity of solute movement is a characteristic of _____.

filtration from the glomerular capillaries

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

gout, a painful inflammatory disease that primarily affects the joints

Checkpoint inhibitors work by utilizing which body system?

immune

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

increase, and the urine would be isoosmotic compared to plasma

An individual who has been bitten by a poisonous snake that has a fast-acting toxin would likely benefit from _____.

injection of antibodies to the toxin

The transfer of fluid from the glomerulus to Bowman's capsule ________.

is mainly a consequence of blood pressure in the capillaries of the glomerulus

Compared to wetland mammals, water conservation in mammals of arid regions is enhanced by having more _____.

juxtamedullary nephrons

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

kangaroo rats

Urea is produced in the _____.

liver from NH3 and carbon dioxide

Which of these cells is a phagocytic leukocyte that can engulf a foreign bacterium?

macrophage

The cells and signaling molecules involved in the initial stages of the inflammatory response are ________.

mast cells and histamines

Osmoregulation and excretion are _____.

mechanisms that maintain volume and composition of body fluids

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

Which of these cells is responsible for the rapidity of the secondary immune response?

memory cells

Your friend has a genetic defect that prevents him from repairing DNA damaged during mitosis. What is this called?

mismatch repair deficiency

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

21. 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

36. 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 proteins can be classified as immunoglobulins? I) T cell receptors II) B cell receptors III) Antigens

only II

Lymphocytes mature in the _____. I) spleen II) thymus III) bone marrow

only II and III

What type of immunity is associated with breast feeding?

passive immunity

The role of cytotoxic T cells is the secretion of _____, which plays a role in the _____ immune response.

perforin ... cell-mediated

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

physically trapping of pathogens

Naturally acquired passive immunity can result from the _____.

placental transfer of antibodies

B cells that have been stimulated by interleukin-2 develop into _____.

plasma cells

Which of these cells produce and secrete antibodies?

plasma cells

Which of the following is crucial to activation of the adaptive immune response?

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

Alternative RNA splicing

produces multiple proteins from a single coding gene.

The osmoregulatory/excretory system of a freshwater flatworm is based on the operation of _____.

protonephridia

Double-stranded viral DNA is incorporated into a host cell as a _____.

provirus

Yearly vaccination of humans for influenza viruses is necessary because _____.

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

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 tertiary structure of a protein

relies on multiple weak bonds between side chains.

The fluid with the highest osmolarity is ________.

seawater in a tidal pool

The osmoregulatory process called secretion refers to the _____.

selective elimination of excess ions and toxins from body fluids

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

Increased antidiuretic hormone (ADH) secretion is likely after _____.

sweating-induced dehydration increases plasma osmolarity

When antibodies bind antigens, the clumping of antigens results from _____.

the antibody having at least two binding regions

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

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

the vasa recta

You have a young child. You can get them vaccinated for all of the following diseases except?

tonsilitis

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

triggers clonal expansion of lymphocytes

The site of inflammation may become swollen due to the increased numbers of cells and fluids at the site and painful due to signals from pain receptors.

true

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