Biology HESI A2 Practice Test

Correct Answer: C

Rationale: The correct answer is C because both prokaryotic and eukaryotic cells possess a cell membrane. The cell membrane is a crucial structure present in all cells that separates the internal cellular environment from the external environment. In prokaryotic cells, the cell membrane is the outermost boundary, while in eukaryotic cells, it is surrounded by other membrane-bound organelles. Choice A is incorrect because prokaryotic cells lack membrane-bound organelles, but they still have a cell membrane. Choice B is incorrect because eukaryotic cells do possess a cell membrane. Choice D is incorrect as it contradicts the basic understanding of cell biology.

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: C

Rationale: The correct answer is C: Tight junctions. Tight junctions are specialized connections between cells that form a barrier to prevent leakage of substances between cells. They are important for maintaining the integrity and function of epithelial and endothelial tissue. Separate desmosomes (choice A) are incorrect because desmosomes are anchoring junctions, not tight junctions. Ronofilaments (choice B) is not a term related to cell junctions. Fascia adherens (choice D) is incorrect as it refers to a type of adherens junction, not tight junctions.

Correct Answer: A

Rationale: Step 1: Define the biosphere - It is the part of the Earth where life exists, including land, water, and air. Step 2: Evaluate statement A - It correctly defines the biosphere as the part of Earth supporting life. Step 3: Evaluate statement B - It is incorrect because the biosphere does not encompass the entire surface of the Earth. Step 4: Conclusion - Statement A is correct as it accurately describes the biosphere. Other choices are incorrect as they either misrepresent or contradict the definition of the biosphere.