HESI A2 Biology Practice Test

Correct Answer: B

Rationale: The correct answer is B: Create energy. Mitochondria are known as the powerhouse of the cell because they produce ATP, the primary energy source for cellular functions. They do this through a process called cellular respiration. Option A is incorrect as the nucleus controls the cell. Option C is incorrect as protein synthesis occurs in the ribosomes. Option D is incorrect as waste packaging is typically done by lysosomes.

Correct Answer: B

Rationale: The correct answer is B: Troposphere, stratosphere, mesosphere, thermosphere, exosphere. Rationale: 1. Troposphere: Closest to the Earth's surface where weather occurs. 2. Stratosphere: Contains the ozone layer, which absorbs UV radiation. 3. Mesosphere: Middle layer where meteors burn up. 4. Thermosphere: Upper layer with high temperatures and auroras. 5. Exosphere: Outermost layer where atmosphere transitions to space. Summary: A: Incorrect order, starts with exosphere which is the outermost layer. C: Incorrect order, mesosphere is placed before troposphere. D: Incorrect order, thermosphere comes before troposphere.

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: 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 mitosis is essential for the growth and repair of body tissues. During mitosis, a cell divides to produce two identical daughter cells with the same genetic information as the parent cell. This process is crucial for replacing damaged or dead cells, allowing for growth and tissue repair. A is incorrect because mitosis does not involve the fusion of male and female gametes, which is a process called fertilization. B is incorrect because mitosis actually maintains genetic consistency within a species by producing genetically identical cells. C is incorrect because mitosis typically produces cells that are very similar to the parent cell, ensuring the preservation of genetic information and function.