1. The stratified cuboidal epithelium lining the salivary glands is responsible for:

A. Protection
B. Gas exchange
C. Secretion
D. Absorption

Correct answer: C

Rationale: The correct answer is C: Secretion. The stratified cuboidal epithelium lining the salivary glands is specifically designed for the secretion of saliva, which plays a crucial role in the initial digestion of food. This type of epithelium has multiple layers of cells that provide protection and support for the glandular tissue underneath, allowing for the production and release of saliva. Options A, B, and D are incorrect as they do not accurately reflect the primary function of this particular epithelium. Therefore, the correct choice is C, secretion.

2. How does the potential energy of an object change when it is compressed?

A. Potential energy decreases
B. Potential energy increases
C. Potential energy remains constant
D. Potential energy becomes zero

Correct answer: b

Rationale: When an object is compressed, it stores potential energy due to its altered position or configuration.

3. 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.

4. What is the work done by a force of 20 N acting on an object that moves 5 meters in the direction of the force?

A. 100 Joules (J)
B. 25 Joules (J)
C. 4 Joules (J)
D. Work cannot be determined without knowing the object's mass.

Correct answer: A

Rationale: Work is defined as the force applied multiplied by the distance moved in the direction of the force. Work = force x distance = 20 N x 5 m = 100 J.

5. According to the wave theory of light, the bright fringes observed in a double-slit experiment correspond to:

A. Constructive interference
B. Destructive interference
C. Increased diffraction
D. Total internal reflection

Correct answer: A

Rationale: The correct answer is A: Constructive interference. According to the wave theory of light, when two light waves meet in phase (crest to crest or trough to trough), they combine to produce a brighter fringe. This is known as constructive interference, leading to the formation of bright fringes in a double-slit experiment. Destructive interference, on the other hand, occurs when two waves are out of phase (crest to trough), resulting in a dimmer or dark fringe. Increased diffraction refers to the bending of light waves around obstacles, not the formation of bright fringes. Total internal reflection is a phenomenon that occurs at the boundary between two different mediums when light is reflected back into the original medium. Therefore, the bright fringes observed in a double-slit experiment correspond to constructive interference.

6. Which of the following is the main organ responsible for filtering urine?

A. Kidneys
B. Bladder
C. Ureters
D. Urethra

Correct answer: A

Rationale: Rationale: The kidneys are the main organs responsible for filtering urine. They play a crucial role in the urinary system by filtering waste products and excess substances from the blood to produce urine. The urine then travels from the kidneys to the bladder through the ureters, where it is stored until it is expelled from the body through the urethra. The bladder stores urine temporarily, while the ureters are tubes that transport urine from the kidneys to the bladder. The urethra is the tube through which urine is expelled from the body.