HESI A2 Biology Practice Test 2024

Correct Answer: B

Rationale: The correct answer is B: Glycolysis. This is the initial step in the metabolism of food to cellular energy because it involves the breakdown of glucose to produce ATP, the cell's energy currency. Glycolysis occurs in the cytoplasm and does not require oxygen. The Citric Acid Cycle (A) and Electron Transport Chain (C) occur after glycolysis in cellular respiration. Photosynthesis (D) is the process by which plants convert light energy into chemical energy, not the metabolism of food for cellular energy.

Correct Answer: B

Rationale: Passive transport is the term for the movement of ions and other molecular substances across cell membranes without the need for energy. This process relies on the concentration gradient to drive molecules from an area of high concentration to an area of low concentration. Unlike active transport (choice A), which requires energy, passive transport does not involve energy consumption. Diffusion (choice C) is a type of passive transport where molecules move freely across the membrane. Osmosis (choice D) is a specific type of passive transport involving the movement of water molecules across a selectively permeable membrane.

Correct Answer: B

Rationale: The correct answer is B: Microtubules. Microtubules are cylindrical structures made up of tubulin proteins that provide structural support and serve as tracks for cellular movement. They are involved in various cellular processes, including cell motility and intracellular transport. Microfilaments (A) are involved in cell shape and movement but are not primarily responsible for cell propulsion. Flagella (C) and Cilia (D) are cellular appendages that aid in cell movement, but they are composed of microtubules and are not the primary structures responsible for providing the cell with the ability to move and propel.

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: 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.