Biology HESI A2 Practice Test

Correct Answer: A

Rationale: The correct answer is A: hypothesis. A hypothesis is a statement that proposes an explanation for a phenomenon based on available evidence. It helps guide scientific inquiry by providing a testable prediction. Observations (B) are simply data collected through senses. Experiments (C) involve testing hypotheses through controlled conditions. Conclusions (D) are interpretations drawn from the data collected. Therefore, a hypothesis is the initial statement or explanation of certain events or happenings in the scientific process.

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: 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: prokaryotic. Prokaryotic cells lack membrane-bound organelles and a defined nucleus. They have a simple structure with genetic material floating freely in the cytoplasm. Eukaryotic cells (choice A) have membrane-bound organelles and a nucleus. Embryonic (choice B) refers to a developmental stage, not a cell classification. Symbiotic (choice D) relates to a mutually beneficial relationship between two organisms, not cell classification. In summary, prokaryotic cells are characterized by their lack of membrane-bound organelles and nucleus, distinguishing them from eukaryotic cells, embryonic stages, and symbiotic relationships.

Correct Answer: B

Rationale: The correct answer is B: Smooth, skeletal, cardiac. Smooth muscle tissue is found in organs and blood vessels, skeletal muscle tissue is attached to bones for movement, and cardiac muscle tissue is found in the heart. The other choices are incorrect because they do not accurately represent the types of muscle tissue in the human body. Choice A includes organs and structures that are not muscle tissues. Choice C lists a neuron (nerve cell), epithelial (covering and lining tissue), and collagen (connective tissue), which are not types of muscle tissue. Choice D is incorrect as it does not provide the correct types of muscle tissue.