1
Why is the sodium ion at the highest concentration in extracellular fluid?
  1. Sodium diffuses freely through the cell membrane.
  2. The sodium/potassium pump removes sodium ions from the cell.
  3. The blood contains a high concentration of sodium.
  4. Sodium is actively taken up by the cells for use in the cytoplasm.
2
What is given to a dehydrated human patient when he or she needs to be given fluids intravenously?
  1. Water, which is hypotonic with respect to body fluids.
  2. Saline at a concentration that is isotonic with respect to body fluids.
  3. Glucose because it is a non-electrolyte.
  4. blood
3
What is the approximate osmolarity of body fluids?
  1. 100 mOsm
  2. 300 mOsm
  3. 1000 mOsm
  4. It is not constantly maintained.
4
One milliequivalent of a ferric (III) ion (Fe+3) is equal to how many millimoles?
  1. 0.13
  2. 0.75
  3. 0.5
  4. 0.25
5
What is the difference between an osmoregulator and an osmoconformer?
  1. Osmoregulators can change the osmotic pressure of their body fluids, while osmoconformers cannot.
  2. Osmoconformers can change the osmotic pressure of their body fluids, while osmoregulators cannot.
  3. Osmoregulators match the osmotic pressure of their cells with that of the environment, while osmoconformers do not.
  4. Osmoconformers match the osmotic pressure of their cells with that of the environment, while osmoregulators do not.
6
Why does a salmon have to be an osmoregulator?
  1. They need to remove excess salt from ocean water.
  2. They move between areas of fresh and salt water.
  3. They travel for short stretches across the land between streams.
  4. Freshwater is osmotically neutral compared with their body fluids.
7
What tends to happen to cells in a hypotonic environment?
  1. They remain the same size.
  2. They shrink due to water loss.
  3. They allow water to flow in and out at the same rate.
  4. They swell due to water gain.
8
Which of the following is a function of the kidney?
  1. osmoregulation
  2. excretion of solid waste
  3. production of oxygen
  4. reabsorption of all nutrients
9
The kidney is made up of over a million nephrons that give it a granular appearance. What is a nephron?
  1. a network of capillaries
  2. the cup-shaped chamber surrounding the glomerulus
  3. the functional unit of the kidney
  4. the bow-shaped artery at the base of medullary pyramids
10
How do juxtamedullary nephrons differ from cortical nephrons?
  1. Juxtamedullary nephrons have a longer loop of Henle, allowing them to regulate urine concentration better than cortical nephrons.
  2. Juxtamedullary nephrons have a shorter loop of Henle, allowing them to regulate urine concentration better than cortical nephrons.
  3. Juxtamedullary nephrons have a larger glomerulus, allowing them to filter blood at a greater rate than cortical nephrons.
  4. Juxtamedullary nephrons have a smaller glomerulus, allowing them to filter blood at a greater rate than cortical nephrons.
11
What is the casing around the glomerulus called?
  1. distal tubule
  2. loop of Henle
  3. Bowman’s capsule
  4. renal pyramid
12
In the loop of Henle, the permeability of the membrane changes. The descending limb and ascending limb are permeable to which of the following, respectively?
  1. solutes and water
  2. proteins and solutes
  3. water and proteins
  4. water and solutes
13
What do humans excrete, and how soluble is it compared to uric acid?
  1. urea, which is less soluble than uric acid
  2. urea, which is more soluble than uric acid
  3. ammonia, which is more soluble than uric acid
  4. ammonia, which is less soluble than uric acid
14
Describe the network of blood vessels of the kidney.
  1. Blood enters and exits the kidney at the renal hilum, and the renal blood supply starts with the branching of the aorta into the renal arteries. They end with the exiting of the renal veins to join the superior vena cava. Each segmental renal artery formed by the splitting of the renal arteries splits again into interlobar arteries and enters the renal columns. These again split to form arcuate arteries, from which cortical radiate arteries radiate out and branch into many afferent arterioles that enter the capillaries supplying the nephrons. Veins trace the path of arteries and have similar names, except there are no segmental veins.
  2. Blood enters and exits the kidney at the renal hilum, and the renal blood supply starts with the branching of the aorta into the renal arteries. They end with the exiting of the renal veins to join the inferior vena cava. Each segmental renal artery formed by the splitting of the renal arteries splits again into interlobar arteries and enters the renal columns. These again split to form arcuate arteries, from which cortical radiate arteries radiate out and branch into many afferent arterioles that enter the capillaries supplying the nephrons. Veins trace the path of arteries and have similar names, except there are no segmental veins.
  3. Blood enters and exits the kidney at the renal hilum, and the renal blood supply starts with the branching of the aorta into the renal arteries. They end with the exiting of the renal veins to join the inferior vena cava. Each segmental renal artery formed by the splitting of the renal arteries splits again into interlobar arteries and enters the renal columns. These again split to form cortical radiate arteries that radiate out and branch into many afferent arterioles that enter the capillaries supplying the nephrons. Veins trace the path of arteries and have similar names, except there are no segmental veins.
  4. Blood enters and exits the kidney at the renal hilum, and the renal blood supply starts with the branching of the aorta into the renal arteries. They end with the exiting of the renal veins to join the inferior vena cava. Each segmental renal artery formed by the splitting of the renal arteries splits again into interlobar arteries and enters the renal columns. These again split to form arcuate arteries, from which cortical radiate arteries radiate out and branch into many afferent arterioles that enter the capillaries supplying the nephrons. Veins trace the path of arteries and have all the same names as the arteries following the same path.
15
Which statement about contractile vacuoles in microorganisms is true?
  1. They exclusively perform an excretory function.
  2. They contain digestive enzymes.
  3. They originate from the cell membrane.
  4. They are only used for fluid storage.
16
Some unicellular organisms, such as the amoeba, ingest food by endocytosis. The food vesicle fuses with a lysosome, which digests the food. Waste is excreted by which process?
  1. exocytosis
  2. filtration
  3. osmoregulation
  4. dilatation
17
What does active transport of K+ in the Malpighian tubules ensure?
  1. Water leaves the Malpighian tubules.
  2. Water moves into the Malpighian tubules.
  3. K+ moves into the Malpighian tubules.
  4. K+ leaves the Malpighian tubules.
18
Flame cells are primitive excretory organs found in which organisms?
  1. arthropods
  2. annelids
  3. mammals
  4. flatworms
19
A cell has a malfunction in its contractile vacuoles. How would this affect the cell?
  1. The cell’s nephrons would no longer be able to reabsorb water.
  2. The cell’s cytoplasm would become very concentrated.
  3. The cell could no longer excrete waste products.
  4. The cell would uncontrollably take on water until it burst.
20
Which toxic substance is formed by nitrogenous waste?
  1. chlorine
  2. potassium
  3. ammonia
  4. sodium
21
What substance is secreted by most aquatic animals, and why?
  1. ammonia, because it can be easily diluted in an aquatic environment
  2. uric acid, because aquatic animals must preserve water
  3. urea, because ammonia needs to be converted before it can safely be stored in the body.
  4. chlorine, because it can easily be converted to a gas
22
Which water-insoluble compound is similar to purines found in nucleic acids and tends to form a white paste or powder?
  1. urea
  2. guanine
  3. ammonia
  4. uric acid
23
The urea cycle is also referred to as the _____ cycle.
  1. Krebs
  2. ornithine
  3. citric acid
  4. uric acid
24
Renin is produced in the kidney nephrons and performs what function?
  1. increases vasoconstriction
  2. prevents loss of sodium
  3. increases blood pressure
  4. prevents water loss
25
Which hormone elicits the “fight or flight” response, and under which circumstance is it released?
  1. anti-diuretic hormone, presence of alcohol in the blood
  2. atrial natriuretic peptide, high blood pressure
  3. aldosterone, low water content in the blood
  4. epinephrine, extreme stress
26
What are the cause and treatment of Addison’s disease?
  1. an excess of uric acid in the blood, uric acid-dissolving drugs
  2. an inability to produce adh, drink excess water
  3. an excess of K+ secretion into the urine, take in excess potassium
  4. an inability to produce aldosterone, take in excess sodium
27
How does atrial natriuretic peptide hormone act to lower blood pressure?
  1. vasoconstrictor
  2. vasodilator
  3. inhibitor
  4. vasopressin
28
Which cells or organs secrete renin?
  1. granular cells of the juxtaglomerular apparatus
  2. the kidneys
  3. the nephrons
  4. water-reabsorbing cells of the collecting duct