Which type of passive transport uses proteins that change shape to move a target molecule through the membrane?

Correct Answer: B

Rationale: The correct answer is B: Carrier proteins. Carrier proteins are involved in facilitated diffusion, a type of passive transport where specific target molecules are moved across the membrane with the help of proteins that change shape. These carrier proteins bind to the target molecule on one side of the membrane, undergo a conformational change, and then release the molecule on the other side. This process is crucial for the selective transport of certain molecules that cannot pass through the membrane by simple diffusion. Choices A and C are incorrect because diffusion and channel proteins do not involve proteins that change shape to transport target molecules selectively. Choice D is incorrect as carrier proteins fit the description provided in the question.

Correct Answer: D

Rationale: Option D is the best example of a hypothesis because it presents a clear cause-and-effect relationship that can be tested through experimentation. It follows the format of 'If [cause], then [effect]' which is characteristic of a hypothesis in scientific research. The statement is specific, testable, and does not rely on personal opinions or biases, making it a strong and valid hypothesis. Choices A, B, and C do not follow the structure of a hypothesis as they lack the cause-and-effect relationship that can be tested through experimentation. They are more like statements or opinions rather than hypotheses.

Correct Answer: B

Rationale: The correct answer is B. When a hard-boiled egg is placed in a beaker of saltwater, the egg will shrivel because water will leave the egg through osmosis. Osmosis is the movement of water from an area of lower solute concentration to an area of higher solute concentration, in this case, from the egg into the saltwater. The higher concentration of solute in the saltwater causes water to move out of the egg, leading to the egg shrinking or shriveling. Choices A, C, and D are incorrect because the egg will not expand, remain the same, or have an outcome different from shriveling when placed in a beaker of saltwater.

Correct Answer: B

Rationale: Glycolysis is the first step in cellular respiration and can occur in both aerobic (presence of oxygen) and anaerobic (absence of oxygen) conditions. In aerobic respiration, glycolysis takes place in the presence of oxygen and continues with the Krebs cycle and the electron transport chain. So, glycolysis does not require the absence of oxygen but can occur in its presence as part of the overall process of aerobic respiration. Choice A is incorrect because glycolysis can occur in the presence of oxygen. Choice C is incorrect because glycolysis is not the final step of fermentation; it is the initial step. Choice D is incorrect because glycolysis is not the final step of anaerobic respiration; it is the first step, followed by further processes to complete anaerobic respiration.

Correct Answer: D

Rationale: Option B correctly states that diploid cells are somatic cells that make up the body tissues and organs in an organism, while haploid cells are gametes involved in sexual reproduction. Option C accurately differentiates diploid and haploid cells based on their chromosome sets - diploid cells have two sets of homologous chromosomes (one from each parent), whereas haploid cells have one set of unpaired chromosomes. Therefore, the correct choice is D, as both statements in options B and C are accurate descriptions of the differences between diploid and haploid cells. Option A is incorrect because diploid and haploid refer to the number of sets of chromosomes in a cell, not whether the organism is multicellular or not.