Correct Answer: B

Rationale: Punctuated equilibrium suggests that evolution is characterized by long periods of relative stasis punctuated by rapid bursts of evolutionary change. This concept, proposed by Stephen Jay Gould and Niles Eldredge, implies that species remain relatively unchanged for extended periods, followed by sudden bursts of rapid evolution. Option A describes the gradualism model, which is different from punctuated equilibrium. Option C is inaccurate as the fossil record is incomplete and biased. Option D is unrelated to the concept of punctuated equilibrium.

Correct Answer: B

Rationale: The primary function of the respiratory system is to deliver oxygen to the bloodstream and remove carbon dioxide. This process occurs through breathing, where oxygen is inhaled into the lungs and then transferred to the bloodstream, while carbon dioxide is removed from the bloodstream and exhaled out of the body. Maintaining body temperature (A), producing antibodies for the immune system (C), and breaking down food molecules for energy (D) are functions of other systems in the body, not the respiratory system. Therefore, the correct answer is B.

Correct Answer: B

Rationale: Conductivity is the correct property that describes a substance's ability to conduct heat or electricity. Reactivity is related to how readily a substance undergoes chemical reactions, not its ability to conduct heat or electricity. Density refers to the mass per unit volume of a substance, which is different from its ability to conduct heat or electricity. Viscosity measures a substance's resistance to flow, not its ability to conduct heat or electricity.

Correct Answer: C

Rationale: The correct answer is graphite. Graphite is a non-metal that is a good conductor of electricity due to its unique electronic structure. While metals are typically known for their conductivity, graphite is an exception to this rule. Copper (choice A), silver (choice B), and gold (choice D) are all metals and are known for their excellent conductivity. Therefore, they do not fit the criteria of the question, which specifically asks for an element that is a good conductor of electricity but is not a metal.

Correct Answer: C

Rationale: The functional group present in ethers is -O-, representing an oxygen atom bonded to two alkyl or aryl groups. Therefore, choice C, 'Ether,' is the correct answer. Choices A, B, and D refer to different functional groups: hydroxyl (-OH), carbonyl (C=O), and amine (NH2), respectively, which are not present in ethers. Ethers are characterized by the oxygen atom bonded to two carbon groups, distinguishing them from the other functional groups mentioned in the choices.