Which of the following is an example of the location and function of cartilage in the body?

Correct Answer: B

Rationale: Cartilage is a type of flexible connective tissue that acts as supportive pads providing cushioning at joints, like those found between the vertebrae of the spine. This specific function of cartilage helps in reducing friction and absorbing shock in these areas, contributing to joint flexibility and protection. Choices A, C, and D do not accurately describe the function and location of cartilage in the body. Option A incorrectly refers to dense connective tissue, which is different from cartilage. Option C describes tendons or ligaments, which are not cartilage. Option D refers to adipose tissue, which is a type of connective tissue that stores fat and provides insulation, but it is not cartilage.

Correct Answer: A

Rationale: The correct answer is A: Ribs. The ribs are part of the skeletal system, providing structure and protection to the thoracic cavity. The trachea, diaphragm, and alveoli are all essential components of the respiratory system. The trachea carries air to and from the lungs, the diaphragm aids in breathing by contracting and relaxing to change the volume of the thoracic cavity, and the alveoli are tiny air sacs where gas exchange occurs in the lungs. Therefore, ribs do not play a direct role in the respiratory process and are not considered a part of the respiratory system.

Correct Answer: C

Rationale: A substance is considered acidic if its pH is less than 7. pH values below 7 indicate acidity, while pH values above 7 indicate alkalinity or basicity. Substances with a pH less than 7 are categorized as acidic, not above it. Therefore, a substance is classified as acidic if its pH is less than 7, making choice C the correct answer. Choices A, B, and D are incorrect because a pH of 12, 9, and 4, respectively, are all above 7, and therefore not indicative of acidity.

Correct Answer: B

Rationale: Ribosomes serve a crucial role in protein synthesis by translating mRNA into proteins. They are not involved in cell movement, protecting the cell from the environment, or aiding in digestion. Choice A is incorrect because ribosomes are not responsible for cell movement. Choice C is incorrect because ribosomes do not primarily protect the cell from its environment. Choice D is incorrect because ribosomes do not have enzymes that aid in digestion.

Correct Answer: C

Rationale: The correct answer is C. RNA serves as a messenger that carries instructions from DNA for protein synthesis. It does not manufacture proteins directly from DNA (choice A), create bonds within DNA (choice B), or form the double helix structure of DNA (choice D). Therefore, the primary role of RNA is to convey information about the correct sequence of proteins to be synthesized based on the DNA sequences it receives.