HESI A2 Biology Practice Test 2024

Correct Answer: B

Rationale: The correct answer is B: Eukaryotic. Animal cells are eukaryotic cells because they have a defined nucleus that houses the genetic material. This nucleus is surrounded by a membrane, along with other membrane-bound organelles like mitochondria and endoplasmic reticulum. Prokaryotic cells (Option A) lack a true nucleus and membrane-bound organelles. Plant cells (Option C) have similar characteristics to animal cells but also have additional features like a cell wall and chloroplasts. Bacterial cells (Option D) are prokaryotic cells and differ significantly from animal cells in structure and function.

Correct Answer: B

Rationale: The magnification of an ocular lens on a microscope is typically 10x. This is because the ocular lens standard magnification is 10x, which, when combined with the objective lens magnification (e.g., 4x, 40x, 100x), gives the total magnification. Therefore, the correct answer is B (10x). Choice A (4x) is incorrect as it is typically the magnification of a lower-powered objective lens, not the ocular lens. Choice C (40x) and Choice D (100x) are incorrect as they are higher magnifications typically associated with objective lenses, not the ocular lens.

Correct Answer: B

Rationale: The correct answer is B: Vacuoles (contractile). Contractile vacuoles are responsible for pushing excess water out of the cell through a process called osmoregulation. They maintain the cell's internal water balance by collecting and expelling water to prevent the cell from bursting due to osmotic pressure. Lysosomes (A) are involved in cellular waste disposal, mitochondria (C) are the powerhouse of the cell, and the nucleus (D) contains genetic material but does not play a role in expelling water from the cell.

Correct Answer: B

Rationale: The correct answer is B: Active Transport. Active transport moves substances across the cell membrane against the concentration gradient, requiring energy (usually in the form of ATP). This process is crucial for maintaining cellular homeostasis and allowing the cell to accumulate essential molecules. Passive transport (A) does not require energy and moves substances along the concentration gradient. Facilitated diffusion (C) is a type of passive transport that involves the use of transport proteins to move specific molecules across the membrane. Osmosis (D) is the movement of water across a selectively permeable membrane, also considered a type of passive transport.

Correct Answer: B

Rationale: During metaphase of mitosis, chromosomes align at the cell's equator, forming the metaphase plate. This alignment ensures that during anaphase, sister chromatids separate and move towards opposite poles. Prophase is characterized by chromosome condensation, telophase marks the end of nuclear division. Anaphase involves the actual separation of chromatids. Metaphase is the correct answer as it is the phase where chromosomes are precisely aligned for accurate distribution to daughter cells.