CLEP Biology Organismal Biology & Physiology 5 — Questions and Answers
Question 1: Which type of animal produces amniotic eggs, allowing reproduction on dry land without returning to water?
- Amphibians
- Bony fishes
- Amniotes (reptiles, birds, and mammals) (Correct answer)
- Cartilaginous fishes
Correct answer: Amniotes (reptiles, birds, and mammals)
Amniotes produce eggs (or embryos) with specialized membranes including the amnion, chorion, and allantois that provide a self-contained aquatic environment for the embryo.
Question 2: What is the primary role of surfactant in the human lungs?
- Facilitating oxygen transport across the alveolar membrane
- Reducing surface tension to prevent alveolar collapse during exhalation (Correct answer)
- Trapping pathogens before they reach the alveoli
- Increasing the partial pressure of CO₂ in the alveoli
Correct answer: Reducing surface tension to prevent alveolar collapse during exhalation
Surfactant, produced by type II alveolar cells, lowers surface tension at the air-water interface, preventing alveoli from collapsing when pressure drops during exhalation.
Question 3: The hormone antidiuretic hormone (ADH) increases urine concentration by:
- Stimulating aldosterone release from the adrenal cortex
- Increasing the permeability of the collecting duct to water (Correct answer)
- Reducing glomerular filtration rate to filter less fluid
- Inhibiting reabsorption of sodium in the loop of Henle
Correct answer: Increasing the permeability of the collecting duct to water
ADH (vasopressin) inserts aquaporin-2 channels into the collecting duct epithelium, allowing water to follow the osmotic gradient into the concentrated medullary interstitium.
Question 4: During the process of osmoregulation, marine bony fish face which primary challenge?
- Their body fluids are more concentrated than seawater, so they gain water by osmosis
- Their body fluids are less concentrated than seawater, so they lose water by osmosis (Correct answer)
- They must excrete large amounts of dilute urine to remove excess water
- They produce very concentrated urine to retain ions lost to the environment
Correct answer: Their body fluids are less concentrated than seawater, so they lose water by osmosis
Marine bony fish are hyposmotic to seawater, so water continually leaves by osmosis; they compensate by drinking seawater and excreting ions via the gills.
Question 5: Which blood vessel carries deoxygenated blood from the right ventricle to the lungs?
- Pulmonary vein
- Aorta
- Pulmonary artery (Correct answer)
- Superior vena cava
Correct answer: Pulmonary artery
The pulmonary artery is the only artery in the body that carries deoxygenated blood, transporting it from the right ventricle to the lung capillaries for gas exchange.
Question 6: In plants, the apical meristem is responsible for which type of growth?
- Lateral (secondary) growth increasing stem diameter
- Primary growth elongating roots and shoots (Correct answer)
- Lateral root formation from the pericycle
- Fruit development after fertilization
Correct answer: Primary growth elongating roots and shoots
Apical meristems at root and shoot tips produce cells that elongate to increase the length of roots and shoots, constituting primary growth.
Question 7: Which of the following adaptations allows a deep-diving marine mammal such as a sperm whale to remain submerged for extended periods?
- A higher rate of glycolysis to produce ATP without oxygen
- High concentrations of myoglobin in muscles and a large spleen that stores oxygenated red blood cells (Correct answer)
- The ability to hyperventilate just before diving to maximize blood CO₂
- A reduced heart rate that stops oxygen delivery to non-essential organs permanently
Correct answer: High concentrations of myoglobin in muscles and a large spleen that stores oxygenated red blood cells
Deep-diving mammals store large amounts of oxygen in muscle myoglobin and in a large spleen that contracts to release oxygen-rich red blood cells, extending dive duration.
CLEP Biology Organismal Biology & Physiology 5
Which type of animal produces amniotic eggs, allowing reproduction on dry land without returning to water?