HESI A2 Biology Practice Test

Correct Answer: A

Rationale: Epithelial tissue is primarily found lining the organs, such as the skin, digestive tract, and respiratory tract. This tissue serves as a protective barrier and aids in absorption and secretion. The other choices, heart muscle, tendons, and spinal cord, are not locations where epithelial tissue is typically found. Heart muscle is cardiac muscle tissue, tendons are composed of dense regular connective tissue, and the spinal cord consists of nervous tissue. Therefore, the correct answer is A, organ lining, as it aligns with the typical locations of epithelial tissue in the body.

Correct Answer: D

Rationale: The correct answer is D because in DNA, adenine (A) always pairs with thymine (T), forming two hydrogen bonds. This is known as complementary base pairing, essential for DNA replication and maintenance. Options A, B, and C are incorrect as they do not demonstrate the complementary base pairing rule observed in DNA. Option A (A and G) is incorrect because adenine pairs with thymine, not guanine. Option B (A and C) is incorrect because adenine pairs with thymine, not cytosine. Option C (A and A) is incorrect because in DNA, adenine always pairs with thymine, not with itself.

Correct Answer: B

Rationale: Enzymes are typically proteins because they are biological catalysts made up of amino acids. Proteins have specific structures that allow them to bind to substrates and speed up chemical reactions. Fats, sugars, and neurons do not possess the specific structural properties required for enzyme function. Therefore, the correct answer is B (Proteins).

Correct Answer: B

Rationale: Failed to generate a rationale after 5 retries.

Correct Answer: D

Rationale: Step-by-step rationale: 1. Diploid organisms can be multicellular or unicellular, so A is not universally true. 2. Diploid cells can be somatic or germ cells, so B is not always true. 3. Diploid cells always have two sets of homologous chromosomes, making C true. 4. Since C is true and A and B are not always true, the correct answer is D.