HESI A2 Biology 2024

Correct Answer: A

Rationale: The correct answer is A: Mitochondrion. Mitochondria are known as the powerhouse of the cell due to their role in energy production through cellular respiration. They generate ATP, the main energy currency of the cell, through the citric acid cycle and oxidative phosphorylation. Vacuole (B) stores materials, cell membrane (C) regulates what enters and exits the cell, and ribosome (D) is responsible for protein synthesis. Mitochondria uniquely carry out the process of energy production, making them the correct choice.

Correct Answer: A

Rationale: The correct answer is A: Blue. Blue light is essential for photosynthesis as it is absorbed by chlorophyll, the pigment that drives the process. Blue light helps in vegetative growth and overall plant development. Yellow, green, and orange lights are not as effective as they are not as readily absorbed by plants for photosynthesis. Yellow and green lights do not provide the necessary energy for plant growth, while orange light is less efficient in promoting photosynthesis compared to blue light. Therefore, blue light is the most effective choice for growing green plants indoors.

Correct Answer: A

Rationale: During anaphase, the correct answer is A because it is the phase where chromosomes move to opposite ends of the spindle. This separation ensures that each new cell receives a complete set of chromosomes. Choice B is incorrect because nuclear membrane and nucleoli disintegrate during prophase, not anaphase. Choice C is incorrect as chromatids line up at the center of the spindle during metaphase. Choice D is incorrect as the nuclear membrane and nucleoli do not form during anaphase but rather re-form during telophase.

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.

Correct Answer: C

Rationale: The correct answer is C: Water. In cellular respiration, the raw materials needed are glucose, oxygen, and ADP (adenosine diphosphate) with phosphate. Water is not a direct raw material for cellular respiration; it is a byproduct of the process. Glucose is the primary energy source, ADP with phosphate is used to produce ATP (adenosine triphosphate), and oxygen is the final electron acceptor in the electron transport chain. Therefore, water is not one of the raw materials needed for cellular respiration, making choice C the correct answer.