HESI A2 Biology Practice Test 2024

Correct Answer: B

Rationale: The correct answer is B: Krebs Cycle. This cycle, also known as the citric acid cycle, occurs in the mitochondria of cells and plays a crucial role in generating energy through the oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins. It produces ATP, NADH, and FADH2, which are essential for cellular energy production. The Calvin Cycle (A) and Photosynthesis (C) are involved in the process of converting light energy into chemical energy in plants, not in generating energy during cellular respiration. Fermentation (D) is an anaerobic process that generates energy in the absence of oxygen, but it is not as efficient as aerobic respiration in producing ATP.

Correct Answer: C

Rationale: The correct answer is C: Peroxisomes. Peroxisomes are responsible for detoxifying harmful substances in the cell by using enzymes to break down toxic molecules like hydrogen peroxide. This organelle contains catalase, an enzyme that converts hydrogen peroxide into water and oxygen. Endoplasmic Reticulum (choice A) is involved in protein synthesis and lipid metabolism. Lysosomes (choice B) are responsible for breaking down cellular waste and recycling materials. Golgi Apparatus (choice D) is involved in processing and packaging proteins for secretion. Therefore, Peroxisomes specifically handle detoxification, making it the correct choice.

Correct Answer: C

Rationale: The correct answer is C: 4. Mitosis consists of four phases: prophase, metaphase, anaphase, and telophase. In prophase, chromosomes condense. In metaphase, chromosomes align at the cell equator. In anaphase, sister chromatids separate and move to opposite poles. In telophase, the nuclear envelope reforms. Choices A, B, and D are incorrect because mitosis is a complex process that involves more than 2 or 3 phases.

Correct Answer: D

Rationale: The primary function of the endoplasmic reticulum (ER) in a cell is the transport of materials. The ER consists of a network of membranes that help in the synthesis, folding, and transport of proteins and lipids. It plays a crucial role in the intracellular transport of materials between different cell compartments. This process ensures that newly synthesized proteins and lipids are properly transported to their respective destinations within the cell. The ER also serves as a site for the modification and packaging of proteins before they are transported to other organelles or secreted outside the cell. Therefore, the correct answer is D. Incorrect choices: A: Energy production - This is not the primary function of the ER. Energy production mainly occurs in mitochondria. B: Protein synthesis - While the ER is involved in protein synthesis, its primary function is the transport of materials. C: Waste removal - Waste removal is primarily carried out by lysosomes and peroxisomes in a cell, not the ER

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.