Biology HESI A2 Practice Test

Correct Answer: A

Rationale: The correct answer is A: Atmospheric pressure. Atmospheric pressure is the force per unit area exerted by the weight of the air above a surface in Earth's atmosphere. This pressure is due to the gravitational pull on the air molecules. B: Barometric density is not the correct term. Density refers to the mass of a substance per unit volume, not the force per unit area. C: Aneroid pressure is not a valid term related to the given concept. Aneroid barometers are devices used to measure atmospheric pressure, not a type of pressure itself. D: Barometric pressure is a commonly used term synonymous with atmospheric pressure in the context of weather measurements. However, the term "atmospheric pressure" is more precise and directly correlates with the weight of the air above a surface.

Correct Answer: A

Rationale: The correct answer is A: Atmosphere. The atmosphere is the layer of gases that surrounds a planet. It consists of different layers, including the stratosphere and troposphere mentioned in the other choices. The biosphere refers to the regions on Earth where living organisms exist, not the gases surrounding the planet. Therefore, the correct term for the mixture of gases surrounding a planet is the atmosphere.

Correct Answer: B

Rationale: The correct answer is B: They are haploid cells. Gametes are sex cells (sperm and egg) that contain half the number of chromosomes as somatic cells. This is essential for maintaining the diploid chromosome number during fertilization. Choice A is incorrect because gametes are not diploid, but haploid. Choice C is incorrect because gametes are not somatic cells; somatic cells make up the body tissues and are diploid. Choice D is incorrect because only choice B is true; gametes are haploid, not diploid or somatic.

Correct Answer: B

Rationale: The correct answer is B: Tendons, ligaments. Tendons connect muscles to bones, enabling movement. Ligaments connect bones to each other, providing stability. Muscles and ligaments are not directly involved in connecting muscles to bones. Therefore, option B is the most appropriate choice.

Correct Answer: C

Rationale: The correct answer is C: Prophase, prometaphase, metaphase, anaphase, and telophase. 1. Prophase: Chromosomes condense and become visible. 2. Prometaphase: Nuclear envelope breaks down, spindle fibers attach to chromosomes. 3. Metaphase: Chromosomes line up at the metaphase plate. 4. Anaphase: Sister chromatids separate and move towards opposite poles. 5. Telophase: Chromatids reach poles, nuclear envelope reforms. Other choices are incorrect because they either include incorrect phases (A, B) or repeat phases (D).