Biology HESI A2 Practice Exam

Correct Answer: C

Rationale: The correct answer is C because observing the birds in the wild and recording them in predawn and postdawn hours every day for six months allows the researcher to capture their vocalization pattern accurately. This method ensures that the data collected cover a wide range of time periods and seasons, providing a comprehensive understanding of when the birds vocalize the most. Choice A is incorrect because observing birds in captivity may not reflect their natural behavior, and recording at two-hour intervals might miss the peak vocalization times around dawn. Choice B is incorrect because observing the birds in the wild at one-hour intervals in several seasons could provide useful data but may not specifically target the hypothesis about vocalization around dawn. Choice D is incorrect because comparing recordings of different species does not directly address the hypothesis about the vocalization pattern of the particular bird species around dawn.

Correct Answer: A

Rationale: Condensation is the process in which water vapor cools down and transforms into liquid water. This occurs when the temperature of the air decreases, causing the water vapor to lose energy and condense into liquid droplets. Sublimation is the direct transition from solid to gas phase, not liquid. Precipitation is the process of water falling from the sky in various forms, such as rain or snow, but it does not specifically refer to the transformation of water vapor to liquid. Absorption involves one substance taking in another substance, which is not the process of water vapor becoming liquid water. Therefore, the correct answer is A: condensation.

Correct Answer: A

Rationale: The correct answer is A: Anther. The anther is the part of the plant responsible for producing pollen. It is located at the top of the stamen, one of the male reproductive parts of a flower. Pollen contains the male gametes necessary for fertilization. The other choices, B: Style, C: Stigma, and D: Pistil, are all parts of the female reproductive system of a flower. The style is the tube connecting the stigma to the ovary, the stigma is the sticky part that receives pollen, and the pistil is the entire female reproductive structure. Therefore, they are not involved in the production of pollen.

Correct Answer: A

Rationale: The correct answer is A: transcription. Transcription is the process where RNA is synthesized from a DNA template by RNA polymerase. It involves the synthesis of mRNA, tRNA, or rRNA. During transcription, the DNA double helix is unwound, and RNA polymerase reads the DNA sequence and creates a complementary RNA strand. This process occurs in the nucleus in eukaryotic cells and in the cytoplasm in prokaryotic cells. Choice B, synthesis, is a general term that does not specifically refer to the process of RNA synthesis from DNA. Choice C, translation, is the process where mRNA is used to build a polypeptide chain at the ribosome, not the synthesis of RNA from DNA. Choice D, replication, is the process of copying DNA to produce an identical copy of the original DNA molecule, not the synthesis of RNA from DNA.

Correct Answer: C

Rationale: The correct answer is C: One daughter may have the disease. This is because Duchenne muscular dystrophy is a recessive sex-linked trait carried on the X chromosome. In this scenario, the unaffected father will pass his Y chromosome to his sons, making them unaffected carriers. The mother, being a carrier, has a 50% chance of passing the affected X chromosome to each daughter, resulting in a 50% chance that one daughter may have the disease. The other choices are incorrect because both sons cannot inherit the disease from the mother, and both daughters cannot carry the disease as they would either be unaffected carriers or affected themselves.