1. What is the primary hormone released by the parathyroid glands?

A. Insulin
B. Calcitonin
C. Parathyroid hormone (PTH)
D. Thyroxine

Correct answer: C

Rationale: The primary hormone released by the parathyroid glands is Parathyroid hormone (PTH), which plays a crucial role in regulating calcium levels in the body. Insulin is produced by the pancreas to regulate blood sugar levels and is unrelated to the parathyroid glands. Calcitonin is produced by the thyroid gland and helps regulate calcium levels but is not the primary hormone released by the parathyroid glands. Thyroxine is a hormone produced by the thyroid gland that regulates metabolism and is also not released by the parathyroid glands. Therefore, the correct answer is C: Parathyroid hormone (PTH).

2. Which organelle is responsible for controlling the activities of the cell?

A. Golgi apparatus
B. Mitochondria
C. Nucleus
D. Ribosomes

Correct answer: C

Rationale: Rationale: The nucleus is the organelle responsible for controlling the activities of the cell. It contains the cell's genetic material (DNA) and serves as the command center of the cell, regulating gene expression and directing cellular activities. The nucleus plays a crucial role in cell growth, metabolism, and reproduction. The Golgi apparatus is involved in processing and packaging proteins, the mitochondria are responsible for producing energy in the form of ATP, and ribosomes are involved in protein synthesis. However, none of these organelles have the primary function of controlling the activities of the cell like the nucleus does.

3. What is the name for the process where a solid changes directly into a gas?

A. Evaporation
B. Sublimation
C. Condensation
D. Melting

Correct answer: B

Rationale: Sublimation occurs when a solid directly transforms into a gas without passing through a liquid phase.

4. The major site for nutrient absorption in the digestive system is the:

A. Mouth
B. Stomach
C. Small intestine
D. Large intestine

Correct answer: C

Rationale: The correct answer is C: Small intestine. The small intestine is the major site for nutrient absorption in the digestive system. It is where most of the digestion and absorption of nutrients from food takes place. The small intestine has villi and microvilli that increase its surface area, allowing for efficient absorption of nutrients like sugars, amino acids, and fatty acids into the bloodstream. The mouth is primarily responsible for mechanical digestion through chewing, while the stomach's main function is to break down food with enzymes and acids. The large intestine mainly absorbs water and electrolytes, with minimal nutrient absorption.

5. Which of the following terms refers to a muscle twitch, a single forceful contraction of a muscle fiber?

A. Tetanus
B. Trembling
C. Fasciculation
D. Rigidity

Correct answer: C

Rationale: The correct answer is C: "Fasciculation." A muscle twitch refers to the involuntary contraction of a small group of muscle fibers. Tetanus (choice A) is a sustained contraction of a muscle caused by rapid stimulation. Trembling (choice B) is the shaking or quivering of muscles. Rigidity (choice D) refers to stiffness or inflexibility in muscles. Fasciculation is the term that specifically describes a muscle twitch, which is a single forceful contraction of a muscle fiber. Therefore, choice C is the most appropriate term for this scenario.