which structure controls the hormones secreted by the pituitary gland

ATI TEAS 7

ATI TEAS 7 Science Practice Test

1. Which structure controls the hormones secreted by the pituitary gland?

A. Hypothalamus
B. Adrenal gland
C. Testes
D. Pancreas

Correct answer: A

Rationale: The correct answer is A: Hypothalamus. The hypothalamus controls the release of hormones from the pituitary gland. It acts as a master regulator of the endocrine system by producing releasing and inhibiting hormones that influence the secretion of hormones from the pituitary gland. Choice B, the Adrenal gland, is incorrect because while it plays a role in hormone production, it is not responsible for controlling the pituitary gland's hormones. Choice C, the Testes, and Choice D, the Pancreas, are also incorrect as they are not directly involved in controlling the hormones secreted by the pituitary gland.

2. Which locations in the digestive system are sites of chemical digestion? I. Mouth II. Stomach III. Small Intestine

A. II only
B. III only
C. II and III only
D. I, II, and III

Correct answer: D

Rationale: Chemical digestion occurs in all three locations in the digestive system - the mouth, stomach, and small intestine. Enzymes in the saliva break down carbohydrates in the mouth, gastric juices in the stomach help break down proteins, and enzymes in the small intestine further break down macronutrients like carbohydrates, proteins, and fats. The mouth initiates the digestion of carbohydrates, the stomach digests proteins, and the small intestine continues the breakdown of carbohydrates, proteins, and fats. Choice A is incorrect because chemical digestion does occur in the mouth. Choice B is incorrect as both the stomach and small intestine are sites of chemical digestion. Choice C is incorrect as the mouth is also a location of chemical digestion, not just the stomach and small intestine.

3. When making a dilution, what do you do?

A. Add more solvent to a concentrated solution
B. Change the temperature of the solution
C. Decrease the concentration of a solution
D. All of the above

Correct answer: C

Rationale: When making a dilution, you decrease the concentration of a solution by adding more solvent to a concentrated solution. This process does not involve changing the temperature of the solution, so option B is incorrect. Option A is also incorrect because you are not adding more solute to the solution during dilution. Therefore, the correct answer is C) Decrease the concentration of a solution. Options A and B are incorrect as dilution involves adding more solvent, not solute, and does not require changing the temperature of the solution.

4. What is the relationship between the wavelength (λ) and frequency (f) of a wave with a constant speed (v)?

A. λ = v / f
B. λ = f / v
C. λ = vf
D. λ is independent of f and v

Correct answer: A

Rationale: The relationship between wavelength (λ), frequency (f), and speed (v) of a wave is given by the formula λ = v / f. This formula is derived from the wave equation v = fλ, where v is the speed of the wave, f is the frequency, and λ is the wavelength. By rearranging the equation, we get λ = v / f, indicating that the wavelength is inversely proportional to the frequency when the speed of the wave is constant. Therefore, choice A, λ = v / f, correctly represents the relationship between wavelength and frequency when the speed of the wave is held constant. Choice B, λ = f / v, is incorrect because it represents an inverse relationship between wavelength and speed, which is not the case. Choice C, λ = vf, is incorrect as it implies a direct relationship between wavelength, frequency, and speed, which is not accurate. Choice D, λ is independent of f and v, is incorrect as both frequency and speed affect the wavelength of a wave, as shown by the correct formula λ = v / f.

5. Which of the following enzymes unwinds the double-stranded DNA during replication?

A. Helicase
B. Ligase
C. Nuclease
D. Polymerase

Correct answer: A

Rationale: Helicase is the enzyme responsible for unwinding the double-stranded DNA during replication by breaking the hydrogen bonds between the base pairs. This process creates the replication fork where DNA polymerase can then synthesize new DNA strands. Ligase functions to join Okazaki fragments on the lagging strand, not unwind DNA. Nuclease is involved in DNA repair by removing damaged DNA segments. Polymerase is responsible for synthesizing new DNA strands based on the existing template strands, not for unwinding the DNA.