Biology HESI A2 Practice Exam

Correct Answer: C

Rationale: The correct answer is C: rod-shaped. Bacillus subtilis is a type of bacteria known for its rod-shaped morphology. This shape is characteristic of this specific bacterium and distinguishes it from other bacterial shapes such as spiral (A), globular (B), and grape-like clusters (D). The rod shape of Bacillus subtilis allows it to efficiently reproduce and adapt to various environments. This morphology also plays a role in its motility and survival strategies. By understanding the distinct rod-shaped morphology of Bacillus subtilis, one can accurately identify and differentiate it from other bacterial species.

Correct Answer: D

Rationale: The correct answer is D: Ethyl alcohol fermentation. Beer production involves the conversion of sugars into ethyl alcohol and carbon dioxide by yeast through the process of fermentation. Lactic acid fermentation (A) produces lactic acid, not ethyl alcohol. Acetic acid fermentation (B) produces acetic acid, not ethyl alcohol. Propionic acid fermentation (C) produces propionic acid, not ethyl alcohol. Therefore, option D is the only choice that aligns with the process of beer production.

Correct Answer: D

Rationale: During telophase, the correct answer is D: Two nuclei are formed. This is the final stage of cell division where the nuclear membranes reform around the separated chromosomes, leading to the formation of two distinct nuclei. This process ensures that each daughter cell receives a complete set of chromosomes. Option A is incorrect because the nuclear envelope actually reforms during telophase. Option B is incorrect as organelles do not double in number during telophase. Option C is incorrect because chromosomes actually separate during anaphase, not telophase.

Correct Answer: B

Rationale: The correct answer is B: Hominidae. Homo sapiens belong to the family Hominidae, which includes great apes like chimpanzees, gorillas, and orangutans. This classification is based on shared physical and genetic characteristics. Choice A (Animalia) is incorrect as it refers to the kingdom level of classification. Choice C (Mammalia) is incorrect as it refers to the class level of classification. Choice D (Chordata) is incorrect as it refers to the phylum level of classification. The key is to identify the correct taxonomic level for the family that includes humans.

Correct Answer: B

Rationale: The correct answer is B: Red blood cells lack nuclei. This is because during their maturation process, red blood cells expel their nuclei to make room for hemoglobin, allowing them to carry oxygen efficiently. Nerve cells (A), liver cells (C), and connective tissue cells (D) all have nuclei because they require genetic material for various functions such as protein synthesis, regulation, and repair. Red blood cells, lacking nuclei, are specialized for their main function of transporting oxygen throughout the body.