1. In the cardiovascular system, what is the primary function of red blood cells?

A. To transport oxygen throughout the body.
B. To fight infection and disease.
C. To help regulate blood clotting.
D. To remove waste products from the body.

Correct answer: A

Rationale: The correct answer is A: 'To transport oxygen throughout the body.' Red blood cells contain hemoglobin, a protein that binds to oxygen in the lungs and carries it to tissues throughout the body. This process is essential for cellular respiration, where oxygen is used to produce energy. Red blood cells do not fight infection (B), regulate blood clotting (C), or remove waste products (D); those functions are carried out by other components of the immune and circulatory systems.

2. The term "goiter" refers to a condition characterized by:

A. Overproduction of cortisol from the adrenal glands
B. Excessive growth of the thyroid gland
C. Underproduction of parathyroid hormone (PTH)
D. Deficiency of growth hormone from the pituitary gland

Correct answer: B

Rationale: The term 'goiter' specifically refers to the abnormal enlargement of the thyroid gland. This can be due to various reasons such as iodine deficiency, Hashimoto's thyroiditis, or Graves' disease. Options A, C, and D are incorrect as they describe conditions related to other glands and hormones in the endocrine system. It is important to differentiate between different endocrine disorders to accurately diagnose and treat patients. Therefore, the correct answer is B, as a goiter is characterized by the excessive growth of the thyroid gland.

3. Which structure contains the genetic material (DNA) of the cell?

A. Cytoplasm
B. Nucleus
C. Cell wall (only present in plant cells)
D. Golgi apparatus

Correct answer: B

Rationale: The correct answer is B: Nucleus. The nucleus is the organelle that contains the genetic material (DNA) of the cell. It acts as the control center of the cell, regulating gene expression and coordinating cellular activities. The cytoplasm, option A, is the jelly-like substance that fills the cell and surrounds the organelles, but it does not contain the genetic material. The cell wall, option C, is a rigid structure found in plant cells that provides support and protection, but it does not house the DNA. The Golgi apparatus, option D, is responsible for modifying, sorting, and packaging proteins for secretion, but it does not store the genetic material of the cell. Therefore, the nucleus is the structure that contains the genetic material in a cell.

4. What enzyme plays a crucial role in DNA replication during the S phase of interphase?

A. Helicase
B. DNA polymerase
C. Ligase
D. Topoisomerase

Correct answer: B

Rationale: Rationale: During the S phase of interphase, DNA replication occurs. DNA polymerase is the enzyme responsible for synthesizing new DNA strands by adding nucleotides in a complementary fashion to the template strand. It plays a crucial role in replicating the entire genome accurately. Helicase unwinds the double-stranded DNA, topoisomerase relieves the tension in the DNA strands, and ligase joins the Okazaki fragments on the lagging strand. However, DNA polymerase is the enzyme directly involved in the synthesis of new DNA strands during replication.

5. A solution is formed when:

A. One substance dissolves in another
B. Two or more substances react chemically
C. A solid changes to a liquid
D. None of the above

Correct answer: A

Rationale: One substance dissolves in another. A solution is a homogeneous mixture where one substance (solute) dissolves in another (solvent).

6. 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?