HESI A2 Biology 2024

Correct Answer: A

Rationale: The correct answer is A: Mutualism. This is because mutualism is a symbiotic relationship where both organisms benefit. In this type of relationship, both organisms obtain advantages such as food, protection, or other resources. On the other hand, choices B, C, and D are incorrect. Parasitism (B) involves one organism benefiting at the expense of the other. Commensalism (C) is a relationship where one organism benefits while the other is neither helped nor harmed. Competition (D) is a relationship where organisms compete for limited resources, resulting in one or both organisms being negatively affected. Thus, the most suitable term for a relationship where both organisms benefit is mutualism.

Correct Answer: B

Rationale: During glycolysis, glucose is broken down into molecules of pyruvic acid through a series of enzymatic reactions. This process occurs in the cytoplasm of cells and is the first step in cellular respiration. Pyruvic acid can then enter the citric acid cycle (Kreb's cycle) to further generate ATP. Choice A is incorrect because glucose's energy is not entirely lost but rather partially captured in the form of ATP. Choice C is incorrect as glucose is not stored in NADH but rather NADH is generated during glycolysis. Choice D is incorrect as glucose does not join with molecules of citric acid during glycolysis but rather pyruvic acid is the end product.

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 answer is A. When messenger RNA reaches the cytoplasm, it attaches to a ribosome for protein synthesis. Ribosomes are the cellular machinery responsible for translating the genetic code carried by mRNA into proteins. Option B is incorrect as mRNA does not "unzip" in the cytoplasm. Option C is incorrect because mRNA does not pair with DNA bases in the cytoplasm; it pairs with ribosomes. Option D is incorrect as mRNA does not "pull free" of the DNA strand in the cytoplasm; it has already been transcribed from DNA in the nucleus.

Correct Answer: C

Rationale: The correct answer is C because counting birds at the same feeder at two different times (noon and 6:00 P.M.) provides a more accurate representation of bird activity throughout the day. This method allows the student to observe any variations in bird populations at different times, capturing potential fluctuations in activity levels. Choice A (counting birds at one feeder every 6 hours) may miss out on important changes in bird presence during different times of the day. Choice B (counting birds at three feeders at noon and 6:00 P.M.) increases the complexity and potential for errors in data collection. Choice D (counting birds at three feeders every 6 hours) may lead to redundancy and a lack of focus on specific feeding areas.