Correct Answer: B

Rationale: The correct answer is 'the age of her eggs.' As women age, the quality of their eggs decreases, leading to a higher risk of chromosomal abnormalities and infertility. This decline in egg quality is why advanced maternal age is associated with a higher risk of certain pregnancy complications. Choices A, C, and D are incorrect because the primary concern in this context is related to the age-related changes in a woman's eggs, not sperm, diabetes risk, or cholesterol levels.

Correct Answer: A

Rationale: The correct answer is A: Monomers. Macromolecules are built from smaller subunits called monomers. Monomers join together through chemical reactions to form larger molecules known as macromolecules. Option B is incorrect because it does not provide the accurate information regarding macromolecules. Option C is incorrect as it indicates uncertainty, which is not the case here. Option D is incorrect as there is a specific answer related to the composition of macromolecules.

Correct Answer: B

Rationale: Positive feedback mechanisms amplify or increase changes in a system, moving conditions away from the normal state. This makes choice B the correct answer. Choice A is incorrect as positive feedback does not cause long-term changes but rather accelerates deviations from the norm. Choice C is incorrect because positive feedback does not bring conditions back to normal; instead, it amplifies deviations. Choice D is incorrect as positive feedback does not usually lead to stable conditions but rather to further deviations from the normal state.

Correct Answer: C.

Rationale: The correct answer is 'responsiveness.' Responsiveness refers to the ability of an organism to detect and respond to stimuli in its environment. In this context, it specifically relates to an organism's ability to sense and react to changes within its body. Choices A, B, and D are incorrect. Circulation refers to the movement of fluids within an organism, respiration is the process of exchanging gases, and absorption is the uptake of substances by cells or tissues.

Correct Answer: A

Rationale: The parietal pericardium is a tough, fibrous outer layer that is attached to the diaphragm and the sternum but not directly to the surface of the heart. It forms a sac around the heart known as the pericardial sac. Therefore, the statement that the parietal pericardium is attached to the surface of the heart is false.