HESI A2 Biology Practice Test 2024

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: Gametes. Meiosis is the process of cell division that produces gametes (sex cells) such as sperm and eggs. During meiosis, a diploid cell undergoes two rounds of division to produce four haploid gametes. Somatic cells (choice A) are non-reproductive cells in the body. Zygote (choice C) is a fertilized egg formed by the fusion of sperm and egg, not involved in meiosis. Diploid cells (choice D) have two sets of chromosomes and are the starting cells for meiosis, not the end products. Therefore, gametes are the specific cells involved in meiosis.

Correct Answer: B

Rationale: The correct answer is B: Lipids. The plasma membrane is primarily composed of lipids, specifically phospholipids, which form a lipid bilayer. This structure provides the membrane with its selective permeability properties. Proteins are also present in the membrane, but they are not the primary composition. Carbohydrates are found on the outer surface of the membrane for cell recognition and signaling. Nucleotides are the building blocks of nucleic acids and are not a major component of the plasma membrane.

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: The correct answer is A: ATP. ATP (adenosine triphosphate) is the primary molecule responsible for providing energy to the cell. It stores and transfers energy within cells for various cellular processes. ATP releases energy when the third phosphate group is cleaved off, forming ADP (adenosine diphosphate). DNA (B) is responsible for storing genetic information, not energy. ADP (C) is a product of ATP hydrolysis and not the primary energy molecule itself. Glycogen (D) is a polysaccharide stored in cells for energy reserves, but it is not the primary molecule responsible for providing energy to the cell.