Correct Answer: B

Rationale: The correct answer is B: Neck. A pivot joint, as found in the neck, allows for rotational movement around a single axis. This type of joint is essential for movements like shaking your head 'no' or looking left and right. Choices A, C, and D are incorrect because the hip, shoulder, and elbow joints are examples of ball-and-socket joints, which allow for a wide range of motion in multiple directions, not just rotational movement around a single axis like a pivot joint.

Correct Answer: C

Rationale: The correct answer is C. The ovaries are responsible for producing eggs (ova) and hormones (estrogen and progesterone). They are essential for reproduction, including the release of eggs for fertilization and for regulating the menstrual cycle. The fallopian tubes, as mentioned in choice A, transport eggs from the ovaries to the uterus for potential fertilization. The vagina, described in choice B, serves as the birth canal and also connects the uterus to the external environment. The cervix, as stated in choice D, is the lower part of the uterus that connects it to the vagina and also plays a role in protecting the uterus from infections and serving as a passage for menstrual flow.

Correct Answer: C

Rationale: The correct answer is C: 'Blood would not be pumped to the body.' When tissue in the left ventricle loses blood flow due to a heart attack, the ability of the left ventricle to pump oxygenated blood to the body is compromised. This can lead to serious consequences for the patient's overall health and organ function. Choices A, B, and D are incorrect because a heart attack affecting the left ventricle does not directly impact blood flow from the lungs, cause blood to back up in the legs, or prevent blood from being oxygenated. The primary concern is the compromised ability of the left ventricle to pump blood to the rest of the body, affecting overall circulation and organ perfusion.

Correct Answer: D

Rationale: The correct answer is D: Nucleic acids. Nucleic acids, such as DNA and RNA, are composed of nucleotides and are responsible for storing genetic information and energy (e.g., ATP). Lipids, proteins, and carbohydrates are distinct macromolecules with varying functions and structures. Lipids primarily serve as energy reservoirs, structural components, and cell signaling molecules. Proteins play crucial roles in cellular functions like enzyme activity, structural support, and intracellular signaling. Carbohydrates are mainly utilized as an energy source and for structural purposes within cells.

Correct Answer: B

Rationale: The correct answer is the Integumentary system (Option B). The integumentary system, which includes the skin, hair, nails, and glands, serves various functions such as providing protection against external factors, sensory reception, regulating body temperature (thermoregulation), maintaining water balance (osmoregulation), insulating the body, and absorbing vitamin D from sunlight. The nervous system (Option A) is responsible for transmitting signals throughout the body. The endocrine system (Option C) produces and secretes hormones to regulate bodily functions. The digestive system (Option D) is involved in breaking down food for nutrient absorption. Therefore, the primary functions described in the question align with those of the integumentary system, making it the correct choice.