HESI A2 Biology 2024

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.

Correct Answer: B

Rationale: The correct answer is B: Earthworm. Earthworms have an open circulatory system where the blood is pumped by the rhythmic contraction of vessels and flows among the tissues. This system allows for direct exchange of nutrients and waste products with body tissues. The other choices (A, C, D) have a closed circulatory system where blood is contained within vessels and does not directly contact body tissues, making them incorrect options.

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: B

Rationale: The correct answer is B (50%). Polydactylism is a dominant trait. If both parents have polydactylism, they must be heterozygous (Aa). When they reproduce, the Punnett square shows a 25% chance of AA, 50% chance of Aa, and 25% chance of aa offspring. Thus, 50% of their offspring are predicted to manifest the anomaly. Choice A (25%) is incorrect because that would be the percentage if both parents were homozygous dominant (AA). Choice C (75%) is incorrect because that would be the percentage if both parents were homozygous recessive (aa). Choice D (100%) is incorrect because even though both parents have the trait, they could still be carriers (Aa) and produce offspring without the anomaly.

Correct Answer: B

Rationale: The correct answer is B: Green. Chlorophyll, the pigment responsible for photosynthesis, absorbs light most efficiently in the red and blue regions of the spectrum. Green light is reflected, making it least effective. Violet, orange, and red lights are more readily absorbed by chlorophyll, enhancing photosynthesis. This is due to the specific absorption spectrum of chlorophyll, where green light is least absorbed.