1. Which of the following conditions is characterized by a wasting or decrease in muscle mass?

A. Hypertrophy
B. Atrophy
C. Spasticity
D. Myopathy

Correct answer: B

Rationale: The correct answer is B: 'Atrophy.' Atrophy is a condition characterized by a wasting or decrease in muscle mass. Hypertrophy (choice A) refers to an increase in muscle size, not a decrease. Spasticity (choice C) is increased muscle tone and reflexes, while myopathy (choice D) is a general term for diseases of the muscle tissue. Understanding these definitions is crucial for distinguishing between different muscle conditions.

2. Which of the following is the smallest unit of matter?

A. Molecule
B. Atom
C. Compound
D. Element

Correct answer: B

Rationale: An atom is the fundamental building block of matter, while molecules are formed by the combination of atoms.

3. Myelin sheath is a fatty substance that insulates and protects the long extensions of some nerve cells. It is produced by:

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

Correct answer: A

Rationale: The correct answer is A: Schwann cells. Schwann cells are a type of glial cell in the peripheral nervous system that produce the myelin sheath around axons. Myelin sheath is essential for the rapid conduction of nerve impulses and provides insulation and protection to nerve fibers. Astrocytes are glial cells that provide support and maintain homeostasis in the central nervous system, but they do not produce myelin. Neurons are the main functional units of the nervous system responsible for transmitting nerve impulses. Oligodendrocytes are another type of glial cell in the central nervous system that produce myelin sheath around axons in that region, not in the peripheral nervous system where Schwann cells are responsible for myelination.

4. Cherenkov radiation is a characteristic phenomenon associated with:

A. Alpha particle emission
B. Beta particle emission
C. Gamma ray emission
D. Charged particles exceeding the speed of light in a medium

Correct answer: C

Rationale: Cherenkov radiation is a phenomenon associated with charged particles exceeding the speed of light in a medium. When a charged particle travels faster than the speed of light in that medium, it emits a characteristic blue glow known as Cherenkov radiation. This occurs due to the disruption of the electromagnetic field in the medium by the high-speed particle. Options A, B, and C are not correct as they do not directly relate to the specific condition required for Cherenkov radiation to be produced. Therefore, option D, 'Charged particles exceeding the speed of light in a medium,' is the correct answer.

5. Coronary arteries are responsible for:

A. Delivering oxygenated blood throughout the body.
B. Supplying oxygenated blood to the heart muscle itself.
C. Carrying deoxygenated blood back to the heart.
D. Regulating blood pressure through vasoconstriction and vasodilation.

Correct answer: B

Rationale: The correct answer is B: 'Supplying oxygenated blood to the heart muscle itself.' Coronary arteries are specialized blood vessels that branch off the aorta and provide oxygenated blood to the heart muscle. This is crucial for the heart to function properly and maintain its own blood supply separate from the systemic circulation. The other options are incorrect because delivering oxygenated blood throughout the body is the role of the systemic circulation and not specific to coronary arteries. Carrying deoxygenated blood back to the heart is the function of veins, while regulating blood pressure through vasoconstriction and vasodilation is primarily controlled by arteries in general, not just the coronary arteries.

6. Which of the following is the main function of the liver?

A. To produce bile, which helps digest fats
B. To store energy in the form of glycogen
C. To produce proteins that help to clot blood
D. To detoxify harmful substances in the body

Correct answer: D

Rationale: Rationale: A) The liver does produce bile, which helps in the digestion of fats, but this is not its main function. Bile is stored in the gallbladder and released into the small intestine to aid in the digestion and absorption of fats. B) While the liver does store energy in the form of glycogen, this is not its main function. Glycogen is a form of glucose storage that can be broken down into glucose when the body needs energy. C) The liver does produce proteins that help to clot blood, such as fibrinogen and prothrombin, but this is not its main function. These proteins are essential for the blood clotting process to prevent excessive bleeding. D) The main function of the liver is to detoxify harmful substances in the body. The liver processes and removes toxins, drugs, alcohol, and other harmful substances from the bloodstream, making them less harmful and