Biology Final Exam

Antidiuretic hormone (ADH) and the renin-angiotensin-aldosterone system (the RAAS) work together in maintaining osmoregulatory homeostasis through which of the following ways? a. ADH regulates the osmolarity of the blood by altering renal reabsorption of water, and the RAAS maintains the osmolarity of the blood by stimulating Na+ and water reabsorption. b. ADH and the RAAS work antagonistically; ADH stimulates water reabsorption during dehydration and the RAAS causes increased excretion of water when it is in excess in body fluids. c. Both stimulate the adrenal gland to secrete aldosterone, which increases both blood volume and pressure via its receptors in the urinary bladder. d. ADH and the RAAS combine at the receptor sites of proximal tubule cells, where reabsorption of essential nutrients takes place.

A

If a molecule of carbon dioxide released into the blood in your left toe is exhaled from your nose, it must pass through all of the following EXCEPT _____. a. the pulmonary vein b. an alveolus c. the trachea d. the right atrium

A

Organisms with a circulating body fluid that is distinct from the fluid that directly surrounds the body's cells are likely to have _____.

A closed circulatory system

Which of the following cell types is incorrectly matched with its function? A. parietal—pumps sodium ions into the stomach lumen B. chief—releases pepsinogen into the stomach lumen C. alpha cells in pancreas—makes glucagon D. beta cells in pacreas —makes insulin

A. parietal

Blood is pumped at high pressures in arteries from the heart to ensure that all parts of the body receive adequate blood flow. Capillary beds, however, would hemorrhage under direct arterial pressures. How does the design of the circulatory network contribute to reducing blood pressure to avoid this scenario? a. Blood flow through the capillaries is essentially frictionless, and this reduces the amount of pressure on their walls. b. The total cross-sectional diameter of the arterial circulation increases with progression from artery to arteriole to capillary, leading to a reduced blood pressure. c. Fluid loss from the arteries is high enough that pressure drops off significantly by the time blood reaches the capillaries. d. Capillary beds have the thickest walls of any blood vessel to resist these high pressures.

B

Circulatory systems compensate for _____. a. temperature differences between the lungs and the active tissue b. the slow rate at which diffusion occurs over large distances c. the problem of communication systems involving only the nervous system d. the need to cushion animals from trauma

B

A human red blood cell in an artery of the left arm is on its way to deliver oxygen to a cell in the thumb. To travel from the artery to the thumb and then back to the left ventricle, this red blood cell must pass through _____. a. four capillary beds b. three capillary beds c. two capillary beds d. one capillary bed

C

During most daily activities, the human respiration rate is most closely linked to the blood levels of _____.

Carbon dioxide

In an open circulatory system, blood is _____. a. always inside of vessels and is under higher pressure than in closed circulatory systems b. not always confined to blood vessels and is under higher pressure than in closed circulatory systems c. always inside of vessels and is under lower pressure than in closed circulatory systems d. not always confined to blood vessels and is under lower pressure than in closed circulatory systems

D

Which of the following is the correct sequence of blood flow in birds and mammals? a. left ventricle → aorta → lungs → systemic circulation b. vena cava → right atrium → right ventricle → pulmonary vein c. pulmonary vein → left atrium → left ventricle → pulmonary circuit d. vena cava → right atrium → right ventricle → pulmonary artery

D

The force driving simple diffusion is _____, while the energy source for active transport is _____.

The concentration gradient; ATP

The advantage of excreting nitrogenous wastes as urea rather than as ammonia is that _____.

Urea is less toxic than ammonia

Cyanide poisons mitochondria by blocking the final step in the electron transport chain. Human red blood cells placed in an isotonic solution containing cyanide are likely to _____.

be unaffected

Fluid is filtered from blood as it enters a capillary due to the _____, but fluid is reabsorbed as the blood exits a capillary due to the _____.

blood pressure from the heart; osmotic pressure from proteins in the plasma

The absorption of fats differs from that of carbohydrates in that _____.

most absorbed fat first enters the lymphatic system, whereas carbohydrates directly enter the blood

Constipation can result from the consumption of a substance that _____.

promotes water reabsorption in the large intestine

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

sweating-induced dehydration increases plasma osmolarity

What is the function of the osmotic gradient found in the kidney? The osmotic gradient allows for _____.

the precise control of the retention of water and electrolytes

In the kidneys, which hormone is most effective at causing increased numbers of aquaporins to be present in collecting duct epithelia, and what is the source of this hormone?

ADH; posterior pituitary gland

Which of the following have valves within them to prevent blood backflow? a. arteries b. veins c. capillaries d. arterioles

B. veins

A fatty acid absorbed into an intestinal cell _____.

Becomes part of a chylomicron

The only vertebrates in which blood flows directly from respiratory organs to body tissues without first returning to the heart are the _____.

Fishes

Compared with the interstitial fluid that bathes active muscle cells, blood reaching these muscle cells in arteries has a _____.

Higher PO2

The pancreas is involved in the digestion of _____. I) protein II) fat III) nucleic acids IV) carbohydrates

I, II, III, and IV

Which of the following mechanisms are used to regulate blood pressure in the closed circulatory system of vertebrates? I) changing the force of heart contraction II) constricting and relaxing sphincters in the walls of arterioles III) adjusting the volume of blood contained in the veins

I, II, and III

Osmoregulation

Process by which animals control solute concentrations and balance water gain and loss

Food being digested in the stomach is in a highly acidic environment. When the food is released from the stomach into the small intestine, why is the environment no longer acidic?

Secretin increases the flow of bicarbonate ions from the pancreas into the small intestine to neutralize the stomach acid

When the digestion and absorption of organic carbohydrates results in more energy-rich molecules than are immediately required by an animal, the excess is _____

Stored as glycogen in the liver and muscles

Which of the following is not a result of the decrease in blood pH?

The affinity of hemoglobin for O2 increases.

As global climate changes we notice some bodies of waters - lakes, ponds, esturaries, are warming too. This also causes evaporation. The ability of fish to obtain oxygen is decreased because

a decrease in its oxygen content of the warmer water which decreases the oxygen gradient in the surrounding water compared to the fish.

You are a physician, and you are seeing a patient who complains of abnormal fatigue during exercise. You find that the immediate problem is a buildup of carbon dioxide in the tissues. What is the most likely cause?

abnormal carbonic anhydrase

Gas exchange in the lungs of mammals occurs in:

alveoli

Most of the carbon dioxide produced by humans is _____.

converted to bicarbonate ions by an enzyme in red blood cells

Large proteins such as albumin remain in capillaries rather than diffusing out, resulting in the _____.

development of an osmotic pressure difference across capillary walls

The bite salts ___

emulsifies fats in the duodenum

The production of red blood cells is stimulated by _____.

erythropoietin

To maintain homeostasis freshwater fish must _____.

excrete large quantities of water

If, during protein starvation, the osmotic pressure on the venous side of capillary beds drops below the hydrostatic pressure, then _____.

fluids will tend to accumulate in tissues

Increased appetite is the typical result of increased levels in the blood of _____.

ghrelin

If ATP production in a human kidney was suddenly halted, urine production would _____. This is an application question. ATP is supplying energy.. so what process of the nephron requires energy - likely something that requires active transport. The synthesis of new ion channels or aquaporins requires energy as well. So, if that energy was not supplied, what would happen to urine production?

increase, and the urine would be isometric compared to plasma

Small swollen areas in the neck, groin, and axillary region are associated with _____.

increased activity of the immune system

After consuming alcoholic beverages or large amounts of caffeine, increased urine excretion is the result of _____.

inhibited secretion of ADH

In a healthy person, after a large meal, the production of _____ will increase. After fasting, the production of _____ will increase

insulin; glucagon

Compared to the seawater around them, most marine invertebrates are _____.

isosmotic

Urea is nitrogen waste that is produced in the _____.

liver from NH3 and CO2

Some human infants, especially those born prematurely, suffer serious respiratory failure (RSD) because of _____.

lung collapse due to inadequate production of surfactant

Processing of filtrate in the proximal and distal tubules _____.

maintains homeostasis of pH in body fluids

The Bohr shift on the oxygen-hemoglobin dissociation curve is produced by changes in _____.

pH

Materials are returned to the blood from the filtrate by which of the following processes?

selective reabsorption

Carbon dioxide levels in the blood and cerebrospinal fluid affect pH. This enables the organism to sense a disturbance in gas levels as _____.

the medulla oblongata, which is in contact with cerebrospinal fluid, monitors pH and uses this measure to control breathing

When the beta cells of the pancreas release insulin into the blood, _____.

the skeletal muscles and the adipose cells take up glucose at a faster rate

What is another expression for the tidal volume during maximal inhalation and exhalation?

vital capacity