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 correct answer is B: Nucleotides. DNA is made up of nucleotides, which are composed of a sugar molecule, a phosphate group, and a nitrogenous base. This structure forms the double helix shape of DNA. Proteins (option A) are not the building blocks of DNA, but they are involved in various cellular functions. Lipids (option C) and carbohydrates (option D) are not the primary components of DNA. Overall, nucleotides are the fundamental units of DNA, making option B the correct answer.

Correct Answer: B

Rationale: The correct answer is B: Cell Membrane. The cell membrane is the most important component contributing to protection, communication, and the passage of substances. It acts as a barrier, protecting the cell from external threats. It also regulates the passage of substances in and out of the cell through selective permeability. Additionally, the cell membrane contains receptors and proteins that facilitate cell communication. A: Cytoplasm is important for various cellular functions but does not directly contribute to protection, communication, or substance passage. C: Cytoskeleton provides structural support but does not primarily contribute to protection, communication, or substance passage. D: Vacuole plays a role in storage and waste management but is not as critical for protection, communication, or substance passage as the cell membrane.

Correct Answer: B

Rationale: The correct answer is B: Golgi Apparatus. The Golgi Apparatus is responsible for packaging, processing, and shipping proteins and lipids produced by the endoplasmic reticulum. It modifies these molecules and packages them into vesicles for transport within the cell or secretion outside the cell. The other choices are incorrect because: A: The nucleus contains genetic material and is responsible for regulating cell activities, not packaging and shipping. C: The endoplasmic reticulum is involved in protein synthesis and lipid metabolism, but it is the Golgi Apparatus that processes and packages these molecules. D: Ribosomes are responsible for protein synthesis, not packaging and shipping.

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.