[EXAM 1] Mastering Biology 3 - Osmoregulation

What is the basic functional unit of the kidney? ------------------------------- The nephron. The Malpighian tubule. The renal corpuscle. The medulla.

The nephron.

Glucose is removed from filtrate by _____. ------------------------------- secretion diffusion dialysis active transport osmosis

active transport

The outer part of the kidney is the _____. ------------------------------- medulla nephron lacteal cortex Bowman's capsule

cortex

Increased antidiuretic hormone (ADH) secretion is likely after _____. ------------------------------- sweating-induced dehydration increases plasma osmolarity blood pressure becomes abnormally high drinking lots of pure water eating a small sugary snack

sweating-induced dehydration increases plasma osmolarity

The force driving simple diffusion is _____, while the energy source for active transport is _____. ------------------------------- phosphorylated protein carriers; ATP the concentration gradient; ADP transmembrane pumps; electron transport the concentration gradient; ATP

the concentration gradient; ATP

The most abundant solute in urine is _____. ------------------------------- glucose water plasma proteins sodium chloride urea (and other nitrogenous wastes)

urea (and other nitrogenous wastes)

Which of the following statements best describes the actions of the hormone ADH on the nephron? ------------------------------- ADH causes the proximal tubule to increase glucose reabsorption when the body's energy needs are high. ADH causes the loop of Henle to increase urea reabsorption under conditions of dehydration. ADH causes the distal tubule to increase Na+ reabsorption when Na+ levels in the blood are low. ADH causes the collecting duct to increase water reabsorption by the surrounding tissue under conditions of dehydration.

ADH causes the collecting duct to increase water reabsorption by the surrounding tissue under conditions of dehydration.

Select the correct statement about osmoregulation. ------------------------------- All marine invertebrates are stenohaline. All osmoconformers are marine animals. The less the gradient between an animal's internal osmolarity and its external osmolarity (that of its surroundings), the higher the cost of osmoregulation.

All osmoconformers are marine animals.

What is the driving force for the filtration of blood by the renal corpuscle? ------------------------------- The diffusion of small solutes such as urea down a concentration gradient. Higher pressure in glomerular capillaries than in the surrounding Bowman's capsule. The presence of large pores in the glomerular capillaries and filtration slits. The presence of microvilli.

Higher pressure in glomerular capillaries than in the surrounding Bowman's capsule.

In which region of the nephron is a steep osmotic gradient created? ------------------------------- Proximal tubule. Loop of Henle. Collecting duct. Distal tubule.

Loop of Henle.

Which of the following represents the correct sequence of flow through the nephron? ------------------------------- Renal corpuscle > proximal tubule > loop of Henle > distal tubule > collecting duct Distal tubule > loop of Henle > collecting duct > renal corpuscle > proximal tubule Renal corpuscle > distal tubule > proximal tubule > loop of Henle > collecting duct Renal corpuscle > loop of Henle > collecting duct > proximal tubule > distal tubule

Renal corpuscle > proximal tubule > loop of Henle > distal tubule > collecting duct

Which regions of the nephron function independently of hormonal control for the most part? ------------------------------- Distal tubule and collecting duct. Renal corpuscle and collecting duct. Proximal tubule, loop of Henle, and distal tubule. Renal corpuscle, proximal tubule, and loop of Henle.

Renal corpuscle, proximal tubule, and loop of Henle.

Which of the following statements is true? ------------------------------- The kidneys are paired organs that remove nitrogenous wastes from the urine. The kidneys regulate water and blood glucose in terrestrial vertebrates. Most humans have one kidney, which regulates water and electrolyte balance, removes nitrogenous wastes from the blood, and eliminates the wastes in the urine. The kidneys are paired organs that regulate water and electrolyte balance in terrestrial vertebrates.

The kidneys are paired organs that regulate water and electrolyte balance in terrestrial vertebrates.

Select the correct statement describing the osmolarity of mammalian urine. ------------------------------- The osmolarity of mammalian urine varies little between species Mammalian urine is always hyperosmotic to blood. The osmolarity of mammalian urine may vary over time.

The osmolarity of mammalian urine may vary over time.

Sharks live in seawater. Their tissues are isotonic to seawater, but their concentrations of sodium ions, potassium ions, and chloride ions in cells and extracellular fluids are similar to those of freshwater fishes. How is that possible? ------------------------------- They excrete large quantities of electrolytes. Their blood is hypotonic to their tissues. Urea and trimethylamine oxide contribute to intra- and extracellular osmolarity in shark tissues. Metabolic intermediates of sharks tie up intracellular chloride and potassium ions.

Urea and trimethylamine oxide contribute to intra- and extracellular osmolarity in shark tissues.

Aldosterone is _____. ------------------------------- is released in great quantities when ethanol intoxication takes place triggers the conversion of angiotensinogen into angiotensin II a protein hormone that decreases blood pressure without changing blood volume decreases water reabsorption in the kidneys a steroid hormone that reduces the amount of fluid excreted in the urine

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

Which of these is reabsorbed from filtrate? ------------------------------- sodium chloride glucose water amino acids all of these

all of these

The loop of Henle dips into the renal cortex. This is an important feature of osmoregulation in terrestrial vertebrates because _____. ------------------------------- absorptive processes taking place in the loop of Henle are hormonally regulated the loop of Henle plays an important role in detoxification differential permeabilities of ascending and descending limbs of the loop of Henle are important in establishing an osmotic gradient additional filtration takes place along the loop of Henle

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

To maintain homeostasis freshwater fish must _____. ------------------------------- take in electrolytes through simple diffusion consume large quantities of water excrete large quantities of electrolytes excrete large quantities of water

excrete large quantities of water

A human who has no access to fresh water but is forced to drink seawater instead will _____. ------------------------------- develop structural changes in the kidneys to accommodate the salt overload thrive under such conditions, as long as he has lived at the ocean most of his life excrete more water molecules than taken in, because of the high load of ion ingestion risk becoming overhydrated within twelve hours

excrete more water molecules than taken in, because of the high load of ion ingestion

The movement of substances out of the glomerulus and into Bowman's capsule is referred to as _____. ------------------------------- secretion reabsorption active transport ion pumping filtration

filtration

Which process in the nephron is LEAST selective? ------------------------------- filtration reabsorption active transport secretion

filtration

After drinking alcoholic beverages, increased urine excretion is the result of _____. ------------------------------- increased reabsorption of water in the proximal tubule increased blood pressure inhibited secretion of antidiuretic hormone (ADH) increased aldosterone production

inhibited secretion of antidiuretic hormone (ADH)

The transfer of fluid from the glomerulus to Bowman's capsule _____. ------------------------------- is mainly a consequence of blood pressure in the capillaries of the glomerulus is very selective as to which subprotein-sized molecules are transferred transfers large molecules as easily as small ones results from active transport

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

Compared to the seawater around them, most marine invertebrates are _____. ------------------------------- isoosmotic hypoosmotic hyperosmotic hyperosmotic and isoosmotic

isoosmotic

A necropsy (postmortem analysis) of a marine sea star that died after it was mistakenly placed in fresh water would likely show that it died because _____. ------------------------------- its cells dehydrated and lost the ability to metabolize it was so hypertonic to the fresh water that it could not osmoregulate it was stressed and needed more time to acclimate to the new conditions its contractile vacuoles ruptured

it was so hypertonic to the fresh water that it could not osmoregulate

As filtrate moves down the loop of Henle, the surrounding interstitial fluid becomes _____ concentrated than the filtrate, so _____ leaves the filtrate. ------------------------------- more ... urea less ... urea more ... water less ... water less ... water and urea

more ... water

Which of these is the functional unit of a kidney? ------------------------------- neuron villi nephron alveolus osteon

nephron

The _____ are the major blood vessels transporting blood to the kidneys. ------------------------------- pulmonary arteries glomerulus renal arteries renal veins venae cavae

renal arteries

Urine formed by a kidney collects in the _____ before being drained from the kidney by the _____ and transported to the _____. ------------------------------- urethra ... urinary bladder ... ureter renal pelvis ... medulla ... cortex renal pelvis ... ureter ...urinary bladder renal pelvis ... urethra ... urinary bladder ureter ... renal pelvis ... urinary bladder

renal pelvis ... ureter ...urinary bladder

The movement of substances from the blood into the proximal tubule is known as _____. ------------------------------- filtration dialysis secretion reabsorption none of these

secretion

Materials are returned to the blood from the filtrate by which of the following processes? ------------------------------- selective reabsorption filtration excretion secretion

selective reabsorption