Biology HESI A2 Practice Test

Correct Answer: B

Rationale: Proteins are the best choice to increase muscle mass and strength because they are essential for muscle repair and growth. Proteins are made up of amino acids, which are the building blocks of muscles. Consuming enough protein provides the body with the necessary nutrients to repair and build muscle tissue. Carbohydrates are primarily for energy, lipids are for long-term energy storage, and nucleic acids are not directly involved in muscle growth. Therefore, proteins are the most suitable option for athletes looking to increase muscle mass and strength.

Correct Answer: B

Rationale: The correct answer is B: Taxonomy. Taxonomy is the science of classifying organisms based on their physical characteristics and presumed natural relationships. It involves categorizing organisms into different groups to reflect their evolutionary history. Biology (A) is the broader study of living organisms, not specifically focused on classification. Grouping (C) is a generic term and does not encompass the systematic categorization process of taxonomy. Nomenclature (D) refers to the naming of organisms, not their classification based on physical characteristics and relationships.

Correct Answer: A

Rationale: The correct answer is A: hypothesis. A hypothesis is a statement that proposes an explanation for a phenomenon based on available evidence. It helps guide scientific inquiry by providing a testable prediction. Observations (B) are simply data collected through senses. Experiments (C) involve testing hypotheses through controlled conditions. Conclusions (D) are interpretations drawn from the data collected. Therefore, a hypothesis is the initial statement or explanation of certain events or happenings in the scientific process.

Correct Answer: B

Rationale: The correct answer is B: They lower the activation energy needed. Enzymes lower the activation energy required for a reaction to occur, facilitating the reaction without being consumed in the process. This is crucial in speeding up biological processes. Choices A, C, and D are all true statements about enzymes. A: Enzymes catalyze reactions by speeding up the rate of a chemical reaction. C: Enzymes have an active site where substrate molecules bind, facilitating the reaction. D: Enzymes are typically proteins, although some RNA molecules can also exhibit catalytic activity.

Correct Answer: B

Rationale: The correct answer is B: Cell wall. Plant cells have a rigid cell wall made of cellulose, which provides structural support and protection. Animal cells lack cell walls and instead have a flexible cell membrane for support. Choices A, C, and D (Cell membrane, Ribosome, Chloroplast) are present in both plant and animal cells. The cell membrane controls what enters and leaves the cell, ribosomes are responsible for protein synthesis, and chloroplasts are the site of photosynthesis in plant cells.