HESI A2 Practice Test Biology

Correct Answer: B

Rationale: The correct answer is B: Water keeps temperature stable. Water has a high specific heat capacity, meaning it can absorb and release large amounts of heat without changing temperature significantly. This property helps living things regulate their body temperature by absorbing excess heat in warm environments and releasing stored heat in cold environments. Options A, C, and D are incorrect because water does not directly increase or decrease temperature, but rather helps maintain stability by absorbing or releasing heat as needed.

Correct Answer: A

Rationale: The correct answer is A: Glycolysis. In the process of converting glucose to pyruvate, the first step is glycolysis. This is where glucose is broken down into two molecules of pyruvate, generating ATP and NADH. Glycolysis occurs in the cytoplasm and does not require oxygen. The Krebs cycle (B) occurs in the mitochondria and follows glycolysis, while the electron transport chain (C) and aerobic respiration (D) require oxygen and take place after glycolysis. Therefore, the correct first step in the conversion of glucose to pyruvate is glycolysis.

Correct Answer: A

Rationale: Transcription is the correct answer because it is the process where RNA is synthesized from a DNA template. It involves RNA polymerase binding to the DNA template and creating a complementary RNA strand by matching RNA nucleotides to the DNA template. Translation is incorrect as it involves the synthesis of proteins from mRNA. Transformation is a process in genetics unrelated to protein synthesis. Replication is the process of copying DNA to create two identical DNA molecules, not RNA synthesis from DNA.

Correct Answer: B

Rationale: The correct answer is B: Golgi apparatus. The Golgi apparatus is responsible for modifying, sorting, and packaging proteins and lipids from the endoplasmic reticulum for transport throughout the cell. It receives materials from the ER, processes them, and then directs them to their final destinations. Ribosomes (choice A) are responsible for protein synthesis, lysosomes (choice C) are involved in digestion and waste removal, and vacuoles (choice D) are storage organelles. Therefore, B is the correct answer as it specifically functions in the transportation of materials within the cell.

Correct Answer: A

Rationale: The correct answer is A: Carbohydrates, lipids, protein, and nucleic acids. These are considered the most important molecules in biology because they are essential for various biological functions. Carbohydrates provide energy, lipids are important for cell structure and energy storage, proteins are crucial for cell function and structure, and nucleic acids carry genetic information. Choices B, C, and D are incorrect because calcium, sulfur, and iron are important elements in biology but not considered the most important molecules for biological processes.