HESI A2 Biology Practice Test

Correct Answer: B

Rationale: To focus an image using a compound microscope, adjusting the fine adjustment is correct as it allows for precise focusing when switching magnifications. Coarse adjustment is only used initially to bring the specimen into view, while the stage adjustment is used to center the specimen. Therefore, B is correct as it ensures clear and sharp image focus without unnecessary readjustments. Choices A and C are incorrect as they do not address the specific need for precise focusing when changing magnifications, leading to potential blurriness or loss of focus in the image.

Correct Answer: D

Rationale: Cytokinesis occurs to physically separate the two daughter cells after cell division. This process ensures that each daughter cell receives a complete set of organelles and genetic material. The correct answer, choice D, states that daughter cells can divide, which aligns with the purpose of cytokinesis. Choices A and B are incorrect as they do not directly relate to the process of cytokinesis. Choice C is also incorrect as cytokinesis is not primarily involved in killing bacteria, but rather in ensuring successful cell division.

Correct Answer: A

Rationale: The correct answer is A because the nucleus stores the cell's genetic material, DNA, which contains instructions for cell function and growth. This is crucial for cell division, protein synthesis, and overall cell activities. Choice B is incorrect because the nucleus does not provide structural support to the cell. Choice C is incorrect as protein synthesis primarily occurs in the ribosomes. Choice D is incorrect as energy production from food takes place in the mitochondria, not the nucleus.

Correct Answer: C

Rationale: The correct answer is C: Prometaphase. This phase of mitosis is characterized by the disintegration of the nuclear envelope. During prometaphase, the breakdown of the nuclear envelope allows the spindle fibers to access the chromosomes. This is crucial for the proper alignment and separation of the chromosomes during mitosis. In prophase (choice A), the nuclear envelope starts to break down but is not fully disintegrated. In metaphase (choice D), the nuclear envelope is already broken down, and the chromosomes are aligned at the metaphase plate. Therefore, prometaphase is the specific phase where the nuclear envelope completely disintegrates, making it the correct answer.

Correct Answer: D

Rationale: The correct answer is D because all the statements mentioned in choices A, B, and C are true. A: The respiratory system consists of all organs involved in breathing, including the nose, pharynx, larynx, trachea, bronchi, and lungs. B: Organs included in the respiratory system are the nose, pharynx, larynx, trachea, bronchi, and lungs. C: The respiratory system conveys oxygen into our bodies and removes carbon dioxide from our bodies. Therefore, as all three statements are true, the correct answer is D - All of the Above. The other choices are incorrect because they do not encompass all the organs involved in the respiratory system or the functions it performs.