AP Bio Unit 10 Recommended Review

Which of the following animals generally has the lowest volume of urine production?

A marine bony fish

Which process in the nephron is least selective?

Active transport

In myasthenia gravis, antibodies bind to and block acetylcholine receptors at neuromuscular junctions, preventing muscle contractions. Is this disease best classified as an immunodeficiency disease, an autoimmune disease, or an allergic reaction? Explain.

Autoimmune disease because the immune system produces antibodies against self molecules.

What is the function of the filtration step in excretory systems?

Filtration produces a fluid for exchange processes that is free of cells and large molecules which are of benefit to the animal and could not readily be reabsorbed.

Explain two advantages of having memory cells when a pathogen is encountered for a second time.

Generating memory cells ensures both that a receptor specific for a particular epitope will be present and that there will be more lymphocytes with this specificity than in a host that had never encountered the antigen.

Which of the following is the most likely explanation for hypothyroidism in a patient whose iodine level is normal?

Hyposecretion of TSH

In mammals, milk production by mammary glands is controlled by prolactin and prolactin- releasing hormone. Draw a simple sketch of this pathway, including glands and tissues, hormones, routes for hormone movement, and effects.

I can not add a picture to quizlet, but the answer is in the back of the book so you guys can see it.

Which of the following is not a normal response to increased blood osmolarity in humans?

Production of more dilute urine

Although pus is often seen simply as a sign of infection, it is also an indicator of immune defenses in action. Explain.

Pus contains white blood cells, fluid, and cell debris, it indicates an active and at least partially successful inflammatory response against invading microbes.

What is a characteristic of early stages of local inflammation?

Release of histamine

Which of the following results in long term immunity?

The administration of the chickenpox vaccine.

Many medications make the epithelium of the collecting duct less permeable to water. How would taking such a drug affect kidney output?

The kidney medulla would absorb less water and thus the drug would increase the amount of water lost in the urine.

An epitope associates with which part of an antibody?

Variable regions of a heavy chain and light chain combined

Growth factors are local regulators that

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

HIV targets include all of the following except...

cytotoxic T cells

An example of antagonistic hormones controlling homeostasis is

insulin and glucagon in glucose metabolism

A distinctive feature of the mechanism of action of thyroid hormones and steroid hormones is that

these hormones bind to receptors inside cells

If blood pressure in the afferent arteriole leading to a glomerulus decreased, how would the rate of blood filtration within Bowman's capsule be affected? Explain.

A decline in blood pressure in the afferent arteriole would reduce the rate of filtration by moving less material through the vessels.

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

A mouse species living in a desert

In a glucose tolerance test, periodic measurements of blood glucose level are taken after a person drinks a glucose- rich solution. In a healthy individual, blood glucose rises moderately at first but falls to near normal within 2-3 hours. Predict the results of this test in a person with diabetes mellitus. Explain your answer.

A pathway governed by a short- lived stimulus would be less dependent on negative feedback.

People with herpes simplex type 1 viruses often get mouth sores when they have a cold or similar infection. How might this location benefit the virus?

A person with a cold will produce oral and nasal secretions that facilitate viral transfer. Also since sickness can cause incapacitation or death, a virus that is programmed to exit the host when there is a physiological stress has the opportunity to find a new host at a time when the current host may cease to function.

Which of these is not part of insect immunity?

Activation of natural killer cells

What are the main advantages and disadvantages of relying on a physical barrier against infection?

Advantage is that it provides a very effective defense against infection. Disadvantage is its necessarily incomplete because animals need openings in their bodies for exchange with the environment.

How does alcohol affect regulation of water balance in the body?

Alcohol inhibits the release of ADH, causing an increase in urinary water loss and increasing the chance of dehydration.

Which statement best describes the difference in responses of effector B cells and cytotoxic T cells?

B cells secrete antibodies against a virus; cytotxic T cells kill virus-infected cells.

Suggest a reason why hypothalamic control of oxytocin involves only an inhibiting factor

Because oxytocin responses involve positive feedback from suckling, the pathway does not require a sustained hormonal input stimulus

Which of the following is not an accurate statement

Hormones of the same chemical class usually have the same function

Suppose that a snake handler bitten by a particular venomous snake species was treated with antivenin. Why might the treatment for a second such bite be different?

If the handler developed immunity to proteins in the antivenin, another injection would provoke a severe immune response. The handlers immune system might also now produce antibodies that could neutralize the venom.

If a child were born without a thymus, what cells and functions would be deficient? Explain.

No functional T cells and the child would be unable to produce antibodies against extracellular bacteria because no helper T cells will activate B cells.

To test for tuberculosis in AIDS patients, why wouldn't you inject purified bacterial antigen and assess signs of immune system reaction several days later?

Not sure of answer; their immune systems don't work properly so there might not be any reaction even if TB is present??

Treatment of antibodies with a particular protease clips the heavy chains in half, releasing the two arms of the Y shaped molecule. How might the antibodies continue to function?

Since antigen binding site is intact, the antibody fragments could neutralize viruses and opsonize bacteria,

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

Why could it be dangerous to drink a very large amount of water in a short period of time?

The consumption of a large amount of water in a very short period of time, coupled with an absence of solute intake, can reduce sodium levels in the blood below tolerable levels. This condition, called hyponatremia, leads to disorientation and sometimes respiratory distress.

Kidney failure is often treated by hemodialysis, in which blood diverted out of the body is filtered and then allowed to flow on one side of a semipermeable membrane. Fluid called dialysate flows in the opposite direction on the other side of the membrane. In replacing the reabsorption and secretion of solutes in a functional kidney, the makeup of the starting dialysate is critical. What initial solute composition would work well?

The presence of Na+ and other ions (electrolytes) in the dialysate would limit the extent to which they would be removed from the filtrate during dialysis. Adjusting the electrolytes in the starting dialysate can thus lead to the restoration of proper electrolyte concentrations in the plasma. Similarly, the absence of urea and other waste products in the starting dialysate results in their efficient removal from the filtrate.

You are exploring kidney function in kangaroo rats. You measure urine volume and osmolarity, as well as the amount of chloride and urea in the urine. If the water source provided to the animals were switched from tap water to a 2% NaCl solution, what change in urine osmolarity would you expect? How would you determine if this change was more likely due to a change in the excretion of chloride or urea?

The urine osmolarity would become more concentrated with NaCl and have high saline levels and have a far lower amount of water. I could determine whether this was due to chloride or urea by testing the urine to see how much of it was chloride and how much was urea. Whichever had higher levels would be the cause. (??? not sure on this one, don't trust me)

Which of the following is not true about helper T cells?

They are activated by polysaccharide fragments.

How would a maco=rophange deficiency likely affect a persons innate and acquired defenses?

They would have frequent infections. Causes would be poor innate responses due to diminished phagocytosis and inflammation and poor acquired responses due to the lack of macrophages to present antigens to helper T cells.

How do the mechanisms that induce responses in target cells differ for water- soluble hormones and lipid- soluble hormones?

Water- soluble hormones, which cannot penetrate the plasma membrane, bind to cell- surface receptors. This interaction triggers an intracellular signal transduction pathway that ultimately alters the activity of a preexisting cytoplasmic protein and/ or changes transcription on specific genes in the nucleus. Steroid hormones are lipid- soluble and can cross the plasma membrane into the cell interior, where they bind to receptors located in the cytosol or nucleus. The hormone-receptor complex then functions directly as a transcription factor that binds to the cell's DNA and activates or inhibits transcription of specific genes.

The high osmolarity of the renal medulla is maintained by all of the following except

diffusion of salt from the descending limb of the loop of Henle

The main target organs for tropic hormones are

endocrine glands

Which hormone is incorrectly paired with its action

insulin-stimulates glycogen breakdown in the liver

The relationship between the insect hormones ecdysone and PTTH

is an example of the interaction between the endocrine and nervous system

Unlike an earthworm's metanephridia, a mammalian nephron...

receives filtrate from blood instead of coelomic fluid