Which neurotransmitter controls sleep, mood, and appetite?

Correct Answer: A

Rationale: Serotonin is the correct answer. It is a neurotransmitter that plays a crucial role in regulating mood, sleep, and appetite. Serotonin functions to stabilize and control these physiological processes in the brain and body. Imbalances in serotonin levels are commonly linked to conditions like depression, anxiety, and eating disorders. Oxytocin (Choice B) is more associated with social bonding and childbirth. Cortisol (Choice C) is a stress hormone, and while it can influence mood and appetite in response to stress, it is not primarily responsible for regulating these functions. Aldosterone (Choice D) is a hormone that regulates electrolyte balance and blood pressure, not mood, sleep, and appetite.

Correct Answer: A

Rationale: An HDL cholesterol level of 70 or higher is considered high and beneficial for heart health. Individuals with high HDL levels are usually at lower risk of heart disease. Therefore, a level of 70 or above would warrant regular testing to monitor and maintain heart health. Choices B, C, and D are lower levels of HDL cholesterol, which are not typically considered high enough to warrant regular testing as they may not provide the same level of heart health benefits.

Correct Answer: B

Rationale: A transverse section, also known as a cross-section, divides the body into upper and lower regions. This type of section cuts across the body horizontally, creating a division between the superior (upper) and inferior (lower) portions of the body. Choice A is incorrect as dividing the body into right and left regions is typically done by a sagittal section. Choice C is incorrect as dividing the body into front and back regions is usually achieved by a frontal section. Choice D is incorrect as it refers more to the relationship between dorsal and ventral cavities rather than the actual division of the body.

Correct Answer: A

Rationale: The correct answer is A: Breaking down starch. Amylase is an enzyme that specifically functions to break down starch into smaller sugar molecules such as maltose and glucose. This process is essential for the digestion and absorption of carbohydrates in the body. Choices B, C, and D are incorrect because amylase does not digest fat, break down protein, or absorb water; its primary function lies in starch digestion.

Correct Answer: C

Rationale: The correct answer is C: lymphatic system. The spleen is a vital organ in the lymphatic system, responsible for filtering blood, producing and storing white blood cells, and aiding the body in fighting infections. The lymphatic system is crucial for maintaining the body's immune defenses and fluid balance. Choices A, B, and D are incorrect because the spleen is not part of the nervous system, integumentary system, or urinary system.