what happens to the concentration of hydrogen ions h in a solution as the ph increases

ATI TEAS 7

TEAS 7 practice test science

1. What happens to the concentration of hydrogen ions ($[H^+]$) in a solution as the pH increases?

A. Increases
B. Decreases
C. Remains constant
D. Becomes neutral

Correct answer: B

Rationale: As the pH increases, the concentration of hydrogen ions decreases. The relationship is inversely proportional

2. Which cells myelinate neurons in the CNS?

A. Schwann cells
B. Astrocytes
C. Microglia
D. Oligodendrocytes

Correct answer: D

Rationale: The correct answer is D, Oligodendrocytes. Oligodendrocytes are responsible for myelinating neurons in the central nervous system (CNS). Schwann cells, found in the peripheral nervous system, are responsible for myelinating neurons there. Astrocytes support and maintain the neuronal environment, while microglia function as immune cells in the CNS, participating in immune responses and cellular debris clearance. Therefore, choices A, B, and C are incorrect for myelination of CNS neurons.

3. During nuclear transmutation, a target nucleus is bombarded with a particle to create:

A. A heavier isotope of the same element
B. A lighter isotope of the same element
C. An entirely new element
D. A chain reaction of nuclear fission

Correct answer: C

Rationale: During nuclear transmutation, a target nucleus is bombarded with a particle to create an entirely new element. This process involves changing the number of protons in the nucleus, resulting in the creation of a different element. Options A and B are incorrect because nuclear transmutation leads to the formation of a new element, not a heavier or lighter isotope of the same element. Option D, a chain reaction of nuclear fission, is incorrect as nuclear transmutation involves the direct conversion of one element into another through bombardment with particles, not the initiation of a fission chain reaction.

4. Which hormone is produced by the thyroid gland to regulate metabolism?

A. Adrenaline
B. Thyroxine
C. Cortisol
D. Insulin

Correct answer: B

Rationale: Thyroxine, also known as T4, is the hormone produced by the thyroid gland to regulate metabolism. It is essential for controlling the body's metabolic rate, heart and digestive function, muscle control, brain development, and bone maintenance. Adrenaline is produced by the adrenal glands, not the thyroid gland. Cortisol is produced by the adrenal cortex, not the thyroid gland. Insulin is produced by the pancreas, not the thyroid gland. Therefore, the correct answer is Thyroxine (B).

5. What is the difference between a prokaryotic cell and a eukaryotic cell?

A. Prokaryotic cells have a nucleus, while eukaryotic cells do not
B. Eukaryotic cells have a nucleus, while prokaryotic cells do not.
C. Prokaryotic cells have membrane-bound organelles, while eukaryotic cells do not.
D. Eukaryotic cells have membrane-bound organelles, while prokaryotic cells do not.

Correct answer: B

Rationale: - Prokaryotic cells are simpler and do not have a true nucleus. Their genetic material is located in the nucleoid region, which is not enclosed by a membrane. - Eukaryotic cells are more complex and have a true nucleus that houses the genetic material, enclosed within a nuclear membrane. - Both prokaryotic and eukaryotic cells have organelles, but eukaryotic cells have membrane-bound organelles such as mitochondria, endoplasmic reticulum, and Golgi apparatus, while prokaryotic cells lack these membrane-bound organelles.