1. Which of the following hormones is produced by the adrenal medulla and prepares the body for a stressful situation?

A. Testosterone
B. Cortisol
C. Epinephrine (adrenaline)
D. Growth hormone

Correct answer: C

Rationale: The correct answer is C: Epinephrine (adrenaline). Epinephrine is produced by the adrenal medulla and is responsible for preparing the body for a stressful situation, often referred to as the 'fight or flight' response. Testosterone is a hormone produced by the testes in males and in smaller amounts by the ovaries in females, responsible for male sexual characteristics. Cortisol is produced by the adrenal cortex and plays a role in regulating metabolism and immune response. Growth hormone is produced by the pituitary gland and is essential for growth, cell repair, and metabolism. Therefore, epinephrine is the hormone specifically produced by the adrenal medulla to prepare the body for stress.

2. What is the absolute value of -7?

A. 49
B. 17
C. 7
D. 14

Correct answer: A

Rationale: Absolute value refers to the non-negative distance of a number from zero. Regardless of being positive or negative, 7 is its distance from zero.

3. Which of the following is an example of a polymer?

A. Methane
B. Ethanol
C. Polyethylene
D. Acetic acid

Correct answer: C

Rationale: Polyethylene is a polymer, consisting of a large number of repeating ethylene units. The other choices represent small organic compounds.

4. Which part of the heart generates the QRS complex on an ECG?

A. Sinoatrial node (SA node)
B. Atrioventricular node (AV node)
C. Bundle of His
D. Ventricular muscle cells

Correct answer: D

Rationale: The correct answer is D, ventricular muscle cells. The QRS complex on an ECG represents the depolarization of the ventricles. This electrical activity is generated by the spread of impulses through the bundle branches and Purkinje fibers to the ventricular muscle cells. The SA node (option A) is responsible for initiating the electrical impulse in the heart, but it does not directly generate the QRS complex. The AV node (option B) delays the impulse to allow for proper coordination of atrial and ventricular contractions. The Bundle of His (option C) and its branches facilitate the conduction of the electrical signal from the AV node to the ventricles but do not generate the QRS complex directly.

5. Which of the following is the main function of the skin?

A. To protect the body from harm
B. To regulate body temperature
C. To produce hormones
D. To sense touch, temperature, and pain

Correct answer: A

Rationale: Rationale: A) To protect the body from harm: The skin acts as a physical barrier that protects the body from external threats such as pathogens, UV radiation, and physical injuries. It helps prevent infections and dehydration, making it a crucial function of the skin. B) To regulate body temperature: While the skin does play a role in regulating body temperature through processes like sweating and vasodilation/vasoconstriction, its primary function is protection. C) To produce hormones: Hormone production is primarily carried out by endocrine glands such as the pituitary gland, thyroid gland, and adrenal glands, not the skin. D) To sense touch, temperature, and pain: The skin contains sensory receptors that allow us to perceive touch, temperature, and pain, but this function is secondary to its main role of protecting the body from harm.

6. Dense irregular connective tissue, found in tendons and ligaments, provides:

A. Flexibility
B. Lubrication
C. Insulation
D. Tensile strength

Correct answer: D

Rationale: The correct answer is D: 'Tensile strength.' Dense irregular connective tissue is composed of tightly packed collagen fibers arranged in a random pattern, providing resistance to tension forces. This structural arrangement is ideal for tendons and ligaments, as they need to withstand pulling and stretching forces. 'Flexibility' (A) is more characteristic of elastic fibers, 'Lubrication' (B) is provided by synovial fluid in joints, and 'Insulation' (C) is typically associated with adipose tissue. Therefore, tensile strength is the primary function of dense irregular connective tissue in tendons and ligaments.