Correct Answer: C

Rationale: In a strand of DNA, adenine always pairs with thymine through two hydrogen bonds. This pairing is a fundamental aspect of DNA structure, where adenine and thymine complement each other in the double helix.
Choice A (cytosine) is incorrect because adenine does not pair with cytosine in DNA.
Choice B (uracil) is incorrect as uracil is found in RNA, not DNA.
Choice D (guanine) is incorrect as guanine pairs with cytosine, not adenine, in DNA.

Correct Answer: A

Rationale: The stamen is the male reproductive organ of a plant, producing pollen grains. The pistil, consisting of the stigma, style, and ovary, is the female reproductive organ.
Therefore, the stamen is of a different 'gender' than the other parts of the plant's reproductive system. The pistil, stigma, and style are all part of the female reproductive system, involved in receiving pollen and supporting fertilization. Stamen is the correct answer as it is the male part of a plant's reproductive system, making it different 'gender-wise' from the female parts.

Correct Answer: A

Rationale: When a cell is in a solution where the concentration of solutes is higher inside the cell than outside, it is in a hypertonic environment. In this situation, water will move into the cell in an attempt to equalize the concentration of solutes on both sides of the cell membrane through the process of osmosis. As a result, the cell will swell as it takes in more water, potentially leading to bursting or cell lysis.
Choice B is incorrect because a cell in a hypertonic solution will not shrivel and shrink due to water moving into the cell.
Choice C is incorrect because the cell will not maintain its current size; it will swell.
Choice D is incorrect because growing a supportive cell wall is not the immediate response to being in a hypertonic environment.

Correct Answer: D

Rationale: Glucose is a type of simple sugar and is classified as a carbohydrate. It is commonly found in various carbohydrate-containing foods such as fruits, vegetables, grains, and sugary snacks.
Therefore, the molecule containing glucose would be a carbohydrate, making choice D the correct answer. Proteins (choice
A) are made up of amino acids, lipids (choice
B) are fats, and nucleic acids (choice
C) are DNA and RNA, none of which contain glucose.

Correct Answer: C

Rationale: Nitrification is a biological process in the nitrogen cycle where ammonia is converted into nitrites and then nitrates by bacteria. It is not a step in the water cycle. The water cycle involves processes like evaporation, condensation, precipitation, and transpiration that are related to the movement and transformation of water in the environment.

Choices A, B, and D are all part of the water cycle: condensation is the process where water vapor turns into liquid water, transpiration is the release of water vapor by plants, and absorption refers to the process of water being taken in by soil or other materials.