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 type of wave requires a medium to travel through?

A. Electromagnetic waves
B. Mechanical waves
C. Sound waves
D. Both a and c

Correct answer: d

Rationale: Both mechanical waves (such as sound waves) and electromagnetic waves (like light) have different requirements for propagation, but both can travel through a medium.

3. Which of the following is NOT a type of chemical bond?

A. Ionic bond
B. Covalent bond
C. Metallic bond
D. Gravitational bond

Correct answer: D

Rationale: Although gravity exists, it's not considered a chemical bond responsible for holding atoms together within molecules.

4. The microscopic units responsible for muscle contraction are called

A. Neurons
B. Myofibrils
C. Tendons
D. Sarcomeres

Correct answer: D

Rationale: The correct answer is D: Sarcomeres. Sarcomeres are the fundamental contractile units of skeletal muscle. They are composed of overlapping actin and myosin filaments that slide past each other during muscle contraction, resulting in muscle shortening. Neurons (A) are nerve cells that transmit signals to and from the brain. Myofibrils (B) are thread-like structures within muscle fibers that contain sarcomeres. Tendons (C) are fibrous connective tissues that attach muscles to bones, but they are not directly involved in muscle contraction like sarcomeres are.

5. What is the primary function of the coronary arteries in the cardiovascular system?

A. Carry oxygenated blood to the heart muscle
B. Carry deoxygenated blood from the heart muscle
C. Pump blood to the lungs for oxygenation
D. Regulate blood pressure in the systemic circulation

Correct answer: A

Rationale: The primary function of the coronary arteries in the cardiovascular system is to carry oxygenated blood to the heart muscle. These arteries supply the heart muscle with the necessary oxygen and nutrients it needs to function properly. Without adequate blood flow through the coronary arteries, the heart muscle can become deprived of oxygen, leading to conditions like angina or even a heart attack. Options B, C, and D are incorrect as they do not accurately describe the function of the coronary arteries. Option B is incorrect because the coronary arteries carry oxygenated blood, not deoxygenated blood. Option C is incorrect because the pulmonary arteries, not the coronary arteries, carry blood to the lungs for oxygenation. Option D is incorrect because the regulation of blood pressure in the systemic circulation is primarily controlled by mechanisms such as the kidneys and the autonomic nervous system, not the coronary arteries.

6. What is the scientific name for the common housefly?

A. Musca domestica
B. Drosophila melanogaster
C. Apis mellifera
D. Anopheles gambiae

Correct answer: A

Rationale: Rationale: - Musca domestica is the scientific name for the common housefly. This species is known for being a common pest found in and around human habitations. - Drosophila melanogaster (option B) is a species of fruit fly commonly used in genetic research. - Apis mellifera (option C) is the scientific name for the western honeybee. - Anopheles gambiae (option D) is a species of mosquito known for being a vector of malaria.