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: Mitochondria. Mitochondria are the site of cellular respiration in eukaryotic cells. Here's the rationale: 1. Mitochondria contain enzymes involved in the various stages of cellular respiration. 2. The inner membrane of mitochondria has folds called cristae, which provide a large surface area for aerobic respiration. 3. ATP, the energy currency of the cell, is produced in the mitochondria during cellular respiration. 4. Nucleus (A) houses the genetic material, not involved in cellular respiration. Chloroplasts (B) are found in plant cells and are responsible for photosynthesis, not respiration. Ribosomes (D) are involved in protein synthesis, not cellular respiration.

Correct Answer: B

Rationale: The correct answer is B: Propulsion. This is because propulsion refers to the act of driving or moving something forward, which is exactly what propels the cell forward. Microfilaments (choice A) are involved in providing structural support and movement within the cell, but they do not directly propel the cell forward. Cilia (choice C) and flagella (choice D) are external structures that can help with cell movement, but they do not serve as the primary driving force behind the cell's forward movement. Therefore, choice B is the correct answer as it directly relates to the action of moving the cell forward.

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: A

Rationale: Mitosis is the correct answer as it is the process by which cells divide to form two identical daughter cells for growth, repair, and maintenance. It involves a series of stages such as prophase, metaphase, anaphase, and telophase, ensuring the distribution of genetic material equally. Meiosis is incorrect as it is a process for producing gametes with genetic variation. Binary fission is incorrect as it is a form of asexual reproduction in prokaryotes. Cellular division is too broad and vague, not specifically describing the process of cell division into two identical daughter cells.