1. The "master gland" of the endocrine system, located at the base of the brain, secretes various hormones that control other glands is the:

A. Thyroid gland
B. Pituitary gland
C. Adrenal gland
D. Pancreas

Correct answer: B

Rationale: The correct answer is B: Pituitary gland. The pituitary gland is often referred to as the "master gland" because it plays a crucial role in regulating other endocrine glands in the body. It is located at the base of the brain and secretes various hormones that control functions such as growth, metabolism, reproduction, and stress response. The thyroid gland (A) regulates metabolism, the adrenal gland (C) produces hormones involved in stress response, and the pancreas (D) is primarily responsible for regulating blood sugar levels through insulin production, but they do not serve as the master gland of the endocrine system.

2. What is the term for the distance between the center of a lens or curved mirror and its focal point?

A. Aperture
B. Focal length
C. Refractive index
D. Lens thickness

Correct answer:

Rationale: The focal length of a lens or curved mirror is the distance between its center and the focal point, where parallel light rays converge or appear to diverge from.

3. Which of the following is an example of an aromatic compound?

A. Ethanol
B. Toluene
C. Acetone
D. Butanal

Correct answer: B

Rationale: Toluene is an aromatic compound. The other choices are not aromatic compounds.

4. What is the function of arrector pili muscles?

A. To control sweat production
B. To contract and cause goosebumps
C. To produce sebum
D. To sense touch

Correct answer: B

Rationale: The correct answer is B: 'To contract and cause goosebumps.' Arrector pili muscles are small muscles attached to hair follicles in the skin. When these muscles contract, they cause the hair to stand upright, resulting in the appearance of goosebumps. This physiological response is a remnant of our evolutionary past when our ancestors had more hair, and the raised hair helped to trap air for insulation or to make them look larger when threatened. Therefore, the function of arrector pili muscles is not to control sweat production (A), produce sebum (C), or sense touch (D), but rather to create the physical response of goosebumps.

5. A solution is considered saturated when...

A. More solute can be dissolved
B. The solvent starts to evaporate
C. The solution becomes cloudy
D. It reaches a specific temperature

Correct answer: B

Rationale: The correct answer is B: 'The solvent starts to evaporate.' A solution is considered saturated when the solvent can no longer dissolve any more solute at a given temperature. When the solvent starts to evaporate, it means that the solution is becoming more concentrated and reaching its saturation point. This is a key indicator of a saturated solution. The other options do not accurately describe the concept of a saturated solution, making them incorrect choices.

6. Antigen-antibody binding is the principle behind:

A. Vaccination
B. Disinfection
C. Sterilization
D. antibiotic resistance

Correct answer: A

Rationale: Rationale: Antigen-antibody binding is the principle behind vaccination. When a vaccine containing antigens (weakened or killed pathogens) is introduced into the body, the immune system produces antibodies that bind to these antigens. This binding triggers an immune response, leading to the production of memory cells that provide immunity against future infections by the same pathogen. Vaccination helps the body develop immunity without causing the disease itself, thereby protecting individuals from infectious diseases. Disinfection and sterilization involve different processes to eliminate or reduce pathogens on surfaces or objects. Antibiotic resistance is a phenomenon where bacteria evolve to resist the effects of antibiotics and is not directly related to antigen-antibody binding.