HESI A2 Biology 2024

Correct Answer: C

Rationale: In telophase, the correct answer, new nuclear membranes form around sets of chromosomes. During this phase, the chromosomes become enclosed within their own distinct nuclei. Prophase (A) is the initial phase of mitosis where chromosomes condense but nuclear membranes have not yet formed. Anaphase (B) is when chromosomes are pulled apart towards opposite poles, with no nuclear membrane formation. Interphase (D) is not a phase of mitosis, but the resting phase between cell divisions. Therefore, the correct answer is C as it specifically describes the formation of new nuclear membranes around chromosomes in telophase.

Correct Answer: A

Rationale: The correct order of taxonomic categories from least to most specific is Kingdom, Phylum, Class, Order. This is because taxonomy categorizes organisms based on their shared characteristics, starting from broader groups to more specific ones. Kingdom is the broadest category, followed by phylum, which further narrows down the classification. Class is more specific than phylum, and order is the next level of specificity after class. Therefore, the correct answer is A: Kingdom, phylum, class, order. Choices B, C, and D are incorrect because they do not follow the hierarchical structure of taxonomy. Choice B has the order and class positions switched, choice C has the order and phylum positions switched, and choice D has the class and order positions switched. These alternative choices do not adhere to the principles of taxonomy where classification moves from broader to more specific categories.

Correct Answer: A

Rationale: The correct answer is A: Hydrogen atoms. Saturated fats have all of their carbon atoms bonded to hydrogen atoms, with no double bonds between carbon atoms. This results in a "saturated" molecule with as many hydrogen atoms as possible. Choices B, C, and D are incorrect because saturated fats are not saturated with carbon, oxygen, or nitrogen atoms. These choices do not accurately reflect the chemical structure of saturated fats, which are primarily composed of carbon and hydrogen atoms.

Correct Answer: A

Rationale: The correct answer is A: From the sugar each contains. RNA and DNA derive their names from the type of sugar molecule they contain. RNA stands for Ribonucleic Acid, where "ribo" refers to the sugar ribose, and DNA stands for Deoxyribonucleic Acid, where "deoxyribo" refers to the sugar deoxyribose. This naming convention is based on the specific type of sugar present in each nucleic acid. Summary: - B: From the structure of their nucleotides: While the structure of nucleotides is important in understanding RNA and DNA, it is not the basis for their names. - C: From the information they transfer: While RNA and DNA do transfer genetic information, this is not the primary reason for their names. - D: From their formative processes: The naming of RNA and DNA is not based on their formative processes but rather on the type of sugar they contain.

Correct Answer: C

Rationale: The correct answer is C: Order. Classification starts from the broadest category (Kingdom) to the most specific (Genus). Carnivora is an Order in the classification hierarchy, encompassing various families of carnivorous mammals, including dogs. Therefore, the correct classification for dogs within the Carnivora group is Order. Choices A, B, and D are incorrect because Kingdom refers to the highest taxonomic rank, Class is a level below Order, and Genus is a more specific category than Order.