Which of the following blood vessels contains the least oxygenated blood?

Correct Answer: C

Rationale: The correct answer is C: Pulmonary artery. The pulmonary artery carries deoxygenated blood from the heart to the lungs for oxygenation. This blood is considered the least oxygenated in the body as it has just returned from circulating through the body's tissues and is in need of oxygen replenishment. Choice A, the aorta, is incorrect as it carries oxygenated blood from the heart to the rest of the body. Choice B, the vena cava, carries deoxygenated blood from the body back to the heart. Choice D, the femoral vein, also carries deoxygenated blood back to the heart from the lower extremities.

Correct Answer: C

Rationale: The mass of the ball would be an appropriate control variable for this experiment. By keeping the mass constant, you can ensure that any observed effects are not due to variations in mass but rather to the manipulated independent variable. Controlling the mass helps isolate and identify the true impact of the independent variable being studied. Choices A, B, and D are incorrect. The period and length of the string are more likely to be independent variables or factors being manipulated in the experiment. The color of the ball is considered an extraneous variable that is not typically controlled for in this type of experiment.

Correct Answer: C

Rationale: The hypodermis is the deepest layer of the integumentary system, located below the dermis. It serves as a layer of fat that helps insulate the body, store energy, and provide cushioning. The stratum basale is the deepest layer of the epidermis, not the entire integumentary system. The epidermis is the outermost layer of the skin, followed by the dermis, and then the hypodermis. Therefore, the correct answer is the hypodermis (choice C). Choices A, B, and D are incorrect as they do not represent the deepest layer of the integumentary system.

Correct Answer: A

Rationale: The correct answer is A: Triple beam balance. A triple beam balance is the most suitable lab equipment for measuring mass accurately, which is necessary for this experiment. An anemometer measures wind speed, a hot plate is used for heating substances, and a microscope is used for magnifying objects, none of which are relevant to measuring the mass of chewed gum.

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.