Biology HESI A2 Practice Test

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: B

Rationale: The correct answer is B because antibiotics are designed to target and kill bacteria, not viruses like the flu. Viruses and bacteria are different types of microorganisms with distinct structures and replication mechanisms. Antibiotics work by disrupting bacterial cell processes, which viruses lack. Therefore, using antibiotics for viral infections like the flu is ineffective. Choice A is incorrect because it refers to a different type of infection, not the reason why antibiotics don't work for the flu. Choice C is incorrect because the issue lies in the antibiotic's ineffectiveness against viruses, not the dosage. Choice D is also incorrect as B clearly explains the reason why antibiotics don't work for treating the flu.

Correct Answer: B

Rationale: The scientist needs 12mL, which is equivalent to 0.012L. Since the bottle holds 12L, it contains more than enough solution. Therefore, choice B is correct. Choice A is incorrect because the scientist needs less than the total amount in the bottle. Choice C is incorrect because the scientist actually has more than enough. Choice D is also incorrect as the scientist does have more than required.

Correct Answer: A

Rationale: The correct answer is A: 18 chromosomes. During meiosis, the chromosomes are halved, resulting in gametes with half the number of chromosomes as the parent cell. Since the initial cell had 72 chromosomes, each gamete will have 36 chromosomes after the first division (meiosis I), and then after the second division (meiosis II), each gamete will have 18 chromosomes. Therefore, choice A is correct. Choices B, C, and D are incorrect as they do not reflect the halving of chromosome number during meiosis.

Correct Answer: B

Rationale: The correct answer is B: Actual physical appearance. Phenotype refers to the observable characteristics of an individual, such as physical traits, behavior, and physiological properties. It is the result of the interaction between an individual's genetic makeup (genotype) and environmental factors. Choice A, genetic makeup, refers to genotype. Choice C, recessive alleles, specifically describes a type of gene variant and is not the definition of phenotype. Choice D, None of the above, is incorrect as the phenotype does refer to the actual physical appearance and observable traits of an individual.