1. Myelin sheath, a fatty substance, insulates nerve fibers. What type of tissue is the myelin sheath derived from?

A. Epithelial tissue
B. Muscle tissue
C. Nervous tissue (glial cells)
D. Connective tissue

Correct answer: C

Rationale: The myelin sheath is derived from nervous tissue, specifically from glial cells, which are non-neuronal cells that support and protect neurons in the nervous system. Glial cells, such as Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system, produce the myelin sheath to insulate nerve fibers and enhance the speed of nerve impulse conduction. Epithelial tissue forms the protective covering of internal and external surfaces, muscle tissue is responsible for movement, and connective tissue provides support and structure to the body. Therefore, the correct answer is C: Nervous tissue (glial cells).

2. Micturition involves a combination of:

A. Gravity alone
B. Voluntary muscle contractions only
C. Involuntary muscle contractions only
D. Both voluntary and involuntary muscle contractions

Correct answer: D

Rationale: The correct answer is D: 'Both voluntary and involuntary muscle contractions.' Micturition, also known as urination, is a complex process involving both voluntary and involuntary muscle contractions. The voluntary muscle contractions allow us to control when we urinate, while the involuntary muscle contractions help to expel urine from the bladder. Gravity alone (option A) is not sufficient for micturition, as muscle contractions are necessary to empty the bladder. Similarly, relying on voluntary muscle contractions only (option B) would not be effective, as involuntary contractions are also needed to fully empty the bladder. Lastly, option C stating 'Involuntary muscle contractions only' is incorrect because voluntary muscle contractions play a crucial role in micturition. Therefore, option D is the most comprehensive and accurate choice.

3. In a chemical reaction, the total amount of:

A. Matter remains the same
B. Matter increases
C. Matter decreases
D. Energy remains the same

Correct answer: A

Rationale: The Law of Conservation of Mass states that matter cannot be created or destroyed in a chemical reaction, only rearranged

4. What skin condition is characterized by red, itchy, and inflamed patches?

A. Eczema
B. Psoriasis
C. Melanoma
D. Keloid

Correct answer: A

Rationale: The correct answer is A: Eczema. Eczema is a common skin condition that is characterized by red, itchy, and inflamed patches on the skin. It is often triggered by environmental factors or allergies and can vary in severity. Psoriasis (option B) is also a skin condition that causes red, scaly patches on the skin, but it is typically thicker and more silver or white in color compared to eczema. Melanoma (option C) is a type of skin cancer that usually presents as a new mole or a changing mole on the skin, rather than red, itchy patches. Keloid (option D) is a raised scar that can result from an overgrowth of scar tissue. Therefore, the most appropriate answer to this question is A: Eczema, based on the description of red, itchy, and inflamed patches.

5. A lab report shows a potassium level of 4.5 millimoles per liter (mmol/L). Is this within the normal range of 3.5 to 5.3 mmol/L?

A. No, it is too low.
B. Yes, it is within the normal range.
C. No, it is too high.
D. Cannot be determined without additional information.

Correct answer: B

Rationale: The potassium level of 4.5 mmol/L falls within the normal range provided (3.5 to 5.3 mmol/L). 5. An infant's feeding schedule prescribes 120 milliliters of formula every 3 hours. How many ounces of formula should be prepared for a 24-hour period?