1. What is the name for the hard, protective protein that makes up hair and nails?

A. Collagen
B. Keratin
C. Elastin
D. Fibrin

Correct answer: B

Rationale: The correct answer is B: Keratin. Keratin is the name for the hard, protective protein that makes up hair and nails. Collagen is a structural protein found in connective tissues, while elastin is a protein that allows tissues in the body to resume their shape after stretching. Fibrin is a protein involved in blood clotting. Understanding the different roles of these proteins can help in identifying the correct answer as keratin specifically pertains to hair and nails.

2. Which hormone, produced by the thyroid gland, plays a crucial role in regulating the body's metabolism, growth, and development?

A. Calcitonin
B. Parathyroid hormone (PTH)
C. Thyroxine
D. Insulin

Correct answer: c

Rationale: The correct answer is C: Thyroxine. Thyroxine, also known as T4, is a hormone produced by the thyroid gland that plays a crucial role in regulating the body's metabolism, growth, and development. It controls how the body uses energy, affects heart rate, and influences other vital functions. Calcitonin (A) is involved in calcium regulation, not metabolism. Parathyroid hormone (PTH) (B) is produced by the parathyroid glands and regulates calcium and phosphorus levels in the body. Insulin (D) is a hormone produced by the pancreas that regulates blood sugar levels, not metabolism or growth.

3. What is the function of the Golgi apparatus?

A. Breaking down and recycling cellular waste
B. Packaging and transporting proteins and lipids
C. Generating energy through cellular respiration
D. Translating DNA into proteins

Correct answer: B

Rationale: The correct answer is B: Packaging and transporting proteins and lipids. The Golgi apparatus plays a crucial role in processing, packaging, and distributing proteins and lipids synthesized by the cell. It modifies these molecules and directs them to their appropriate destinations within the cell or for secretion outside the cell. This function is essential for maintaining the proper functioning of the cell and coordinating various cellular processes. Options A, C, and D are incorrect as they describe functions carried out by other cellular organelles, highlighting the specificity and importance of the Golgi apparatus in protein and lipid trafficking.

4. How is power defined in terms of physics?

A. The rate at which work is done
B. The amount of force applied
C. The distance an object travels
D. The potential energy of an object

Correct answer: a

Rationale: Power is defined as the rate at which work is done or the rate at which energy is transferred or converted.

5. The Merkel cells, located in the epidermis, are specialized for:

A. Melanin production
B. Temperature sensation
C. Touch perception
D. Immune defense

Correct answer: C

Rationale: The correct answer is C: 'Touch perception.' Merkel cells, also known as Merkel discs, are found in the skin's epidermal layer and are responsible for sensing touch. These cells are located near nerve endings and help detect light touch and pressure on the skin. They play a crucial role in the perception of tactile sensations and are not involved in melanin production, temperature sensation, or immune defense. Therefore, the specialized function of Merkel cells is primarily related to touch perception, making option C the correct choice.