1. The large intestine absorbs water and electrolytes from digested food material. What waste product remains after water absorption and is eventually eliminated from the body?

A. Chyme
B. Bolus
C. Glucose
D. Feces

Correct answer: D

Rationale: The large intestine is responsible for absorbing water and electrolytes from digested food material. As the waste material moves through the large intestine, most of the water is absorbed, leaving behind waste products known as feces. Feces consist of indigestible material, bacteria, and some remaining waste products. This waste is eventually eliminated from the body through the process of defecation. Chyme refers to the semi-fluid mass of partially digested food that moves from the stomach to the small intestine. Bolus is a term used to describe a mass of chewed food ready to be swallowed. Glucose is a simple sugar that is absorbed in the small intestine and used as an energy source. Therefore, the correct answer is D: Feces.

2. Melanin, the pigment responsible for skin color, is produced by

A. Keratinocytes (These cells produce keratin)
B. Melanocytes
C. Sebocytes (These cells produce sebum)
D. Langerhans cells (These cells are part of the immune system)

Correct answer: B

Rationale: The correct answer is B: Melanocytes. Melanin, the pigment responsible for skin color, is produced by melanocytes, which are specialized cells located in the skin's epidermis. Melanocytes transfer melanin to keratinocytes, the predominant cell type in the epidermis, where it provides protection against UV radiation. Sebocytes produce sebum, an oily substance that helps moisturize the skin and hair. Langerhans cells are a type of immune cell that play a role in the skin's immune response. Therefore, the correct answer is B as melanocytes are specifically responsible for producing melanin.

3. Which of the following is an example of a secondary alcohol?

A. Methanol
B. Ethanol
C. Isopropanol
D. Butanol

Correct answer: C

Rationale: Isopropanol is an example of a secondary alcohol, as the hydroxyl group is attached to a carbon atom that is bonded to two other carbon atoms. The other choices are primary alcohols.

4. What are chromosomes made of?

A. DNA and RNA
B. DNA and proteins
C. Proteins and carbohydrates
D. DNA only

Correct answer: B

Rationale: Rationale: Chromosomes are structures found in the nucleus of cells that contain genetic material. They are made up of DNA (deoxyribonucleic acid), which carries the genetic information, and proteins that help in the organization and packaging of the DNA. While RNA is involved in various cellular processes, it is not a major component of chromosomes. Carbohydrates are not a significant component of chromosomes. Therefore, the most accurate answer is B) DNA and proteins.

5. What is the functional group present in ethers?

A. Hydroxyl
B. Carbonyl
C. Ether
D. Amine

Correct answer: C

Rationale: Ethers have the functional group -O-, representing an oxygen atom bonded to two alkyl or aryl groups. The other choices are associated with different functional groups.