Correct Answer: C

Rationale: The correct answer is the front portion of the parietal lobe. The motor cortex, located in this area, is responsible for planning, controlling, and executing voluntary movements. It plays a crucial role in coordinating the body's movement. Choice A, the top, middle portion of the parietal lobe, is incorrect as this region is more involved in processing sensory information rather than controlling movement. Choice B, the back of the head, is incorrect as it typically refers to the occipital lobe responsible for processing visual information. Choice D, around the auditory cortex, is incorrect as the auditory cortex is primarily involved in processing auditory information, not controlling body movement.

Correct Answer: C

Rationale: The correct answer is option C: Retina. The retina contains photoreceptor cells, including cones that are responsible for color vision. Cones are sensitive to different wavelengths of light, allowing us to perceive and differentiate various colors. Choice A, Cornea, is the transparent outer layer of the eye that helps focus light. It does not play a direct role in color vision. Choice B, Iris, is the colored part of the eye that controls the size of the pupil and regulates the amount of light entering the eye. While it is essential for adjusting light levels, it is not directly involved in color vision. Choice D, Lens, is responsible for focusing light onto the retina. It helps to form clear images on the retina but does not play a role in color vision.

Correct Answer: B

Rationale: The correct answer is B: 'To produce bile and detoxify substances.' The liver's primary functions include producing bile, which aids in the digestion and absorption of fats, and detoxifying harmful substances in the blood. While the liver does play a role in blood filtration, its key functions are related to bile production and detoxification. Choices C and D are incorrect because the liver does not produce insulin (produced by the pancreas) or red blood cells (produced in the bone marrow).

Correct Answer: A

Rationale: The correct answer is the cerebellum. Located at the back of the brain, the cerebellum plays a crucial role in controlling balance, coordination, and fine motor movements. It receives information from the sensory systems, the spinal cord, and other parts of the brain to coordinate voluntary movements and maintain posture. Damage to the cerebellum can result in issues with balance, coordination, and muscle tone. The cerebrum is responsible for higher brain functions like thinking and problem-solving, the medulla oblongata controls vital autonomic functions like breathing and heartbeat, and the brainstem serves as a pathway for neural fibers traveling to and from the brain.

Correct Answer: A

Rationale: The pituitary gland, known as the 'master gland,' plays a crucial role in regulating various physiological processes by secreting hormones that control other endocrine glands. This includes the regulation of metabolism, growth, reproduction, stress response, and more. Therefore, the correct function of the pituitary gland is regulating metabolism, making choice A the correct answer. Choices B, C, and D are incorrect as the pituitary gland is not involved in producing bile, filtering blood, or controlling muscle movement.