- Which feature of osmoregulation is found in both marine and freshwater bony fish?
gain of water through food
A cell type that interacts with both the humoral and cell-mediated immune pathways is a
Helper T cell
A disease that destroys the adrenal cortex should lead to an increase in the plasma levels of
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
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
An inhibitor of which of the following could be used to block the release of calcium from the endoplasmic reticulum?
Yearly vaccination of humans for influenza viruses is necessary because
rapid mutation in flu viruses alters the surface proteins in infected host cells
The advantage of excreting nitrogenous wastes as urea rather than as ammonia is that
urea is less toxic than ammonia
Which of the following are possible advantages of asexual reproduction
it enables species to colonize regions rapidly
Adaptive immunity depends on
Materials are returned to the blood from the filtrate by which of the following processes?
On a submarine expedition to the ocean bottom, you discover a population of fish that are only female. What type of reproduction does this fish most likely use?
Caffeine is an inhibitor of phosphodiesterase. Therefore, the cells of a person who has recently consumed coffee would have increased levels of
The enzyme produced by the kidneys when blood pressure drops, that causes the release of aldosterone
Engulfing-phagocytic cells of innate immunity include all of the following except
Natural killer cells
Regarding their mechanism of action, a difference between steroid and nonsteroid hormones is that
steroid hormones bind to an intracellular receptor and this hormone-receptor complex binds to DNA
Asexual reproduction in animals involves
fission, budding, fragmentation and regeneration, and parthenogenesis
Increasing the temperature of the human scrotum by 2°C (i.e., near the normal body core temperature) and holding it there would
reduce the fertility of the man by impairing spermatogenesis
the receptors on T cells and B cells bind to
For your internship at the local zoo, you have been assigned to help with the new orangutan-breeding program. Little is known about orangutan reproductive hormones, but hormone feedback cycles are often the same in closely related animals. You have been asked to use your knowledge of the interactions of human reproductive hormones to recommend injections to promote ovulation in a female orangutan when a visiting male arrives for a brief breeding visit.
which of the following hormones would you use if you want to induce ovulation right away?
Luteinizing hormone (LH)
In close comparisons external fertilization often yields more offspring than does internal fertilization, but internal fertilization offers the advantage that
the smaller number of offspring produced often receive a greater amount of parental investment and a high probability of survival
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 of the following is a logical explanation for this?
you had an adaptive immunity to that virus
Which of the following would be inhibited by a drug that specifically blocks the addition of phosphate groups to proteins?
receptor tyrosine kinase activity
A newborn who is accidentally given drug that destroys the thymus would most likely
be unable to differentiate and mature T cells
Where and from what compound is urea produced
liver from NH3 and CO2
After sperm cells are produced, they are mainly stored in the
Hermaphroditism is a reproductive strategy in which an individual has both functional male and female reproductive parts. Which of the following would be a possible advantage to such reproductive strategy
the ptential to produce twice as many offspring from a single mating
The steroid hormone that coordinates molting in arthropods is
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?
Different tissues have thyroxine receptors that activate different signal transduction pathways
African lungfish, which are often found in small stagnant pools of freshwater, 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
The mechanism by which epinephrine stimulates breakdown of glycogen within liver cells and skeletal muscle cells
- Provides a specific example of cell communication
- Involves signal transduction
- It requires the action of intracellular proteins/enzymes (such as phosphorylase)
- It is an example of a homeostatic mechanism
All of the above
Testosterone functions inside a cell by
binding with a receptor protein that enters the nucleus and activates specific genes
Mature human sperm and ova are similar in that
they both have the same number of chromosomes
A human who has no access to fresh water but is forced to drink seawater instead
will excrete more water molecules than taken in, because the high load of ion ingestion
Which of the following animals generally has lowest volume of urine production?
a marine bony fish
When a person drinks alcohol, the rate of urination increases. This suggests that antidiuretic hormone(ADH) may be affected by alcohol consumption in some way. Which of the following best accounts for the increase in urination?
Alcohol inhibits the release of ADH
The osmoregulatory/ excretory system of a freshwater flatworm is based on the operation of
Select the pathway that would lead to the activation of cytotoxic T cells
body cell contact antigen-.helper t cell activate-. clonal selection occurs
An inactivating mutation in the progesterone receptor gene would likely result in
the inability of the uterus to support pregnancy
How does urea concentration in urine compare between the two treatment groups?
Urea concentration in urine is much higher in the mice given no water
A decrease in the volume of urine excreted would be expected following
an increase in aquaporin channels in collecting duct
A non functional CD4 protein on a helper T cell would result in the helper T cell being able to
interact with a class II MHC-antigen complex
Which two solutes become more abundant in the kidney medulla interstitial fluid as one progresses deeper into the medulla, and what is the significance of these two gradients?
Urea and NaCl; this promotes better retention of water
The drug furosemide, blocks the transport of Na+ and Cl- in the ascending limb of the loop of Henle. Which of the following effects would you expect the drug to have on urine volume?
increase in urine volume
Which of the following is not a product of the anterior pituitary gland?
In which region would the filtrate be more concentrated?
In which region would the presence of aquaporins channels result in increased water reabsorption in response to release of ADH?
Which mouse was injected?
What hormone was injected?
The table shows the data from the experiment. How does urine osmolarity compare between the two treatment groups?
Urea osmolarity is much higher in mice given no water