1. Dandruff is caused by

A. Excessive sebum production (This can contribute to oily dandruff)
B. Bacterial infection (This can cause scalp folliculitis, not dandruff)
C. Overgrowth of a specific type of fungus on the scalp
D. Lack of proper skin hydration

Correct answer: C

Rationale: Dandruff is primarily caused by an overgrowth of a specific type of fungus called Malassezia on the scalp. This fungus feeds on the natural oils produced by the hair follicles, leading to an inflammatory response in some individuals, resulting in flaking and itching. Excessive sebum production can contribute to oily dandruff by providing more food for the fungus. Bacterial infections, such as scalp folliculitis, can cause symptoms similar to dandruff but are not the primary cause. Lack of proper skin hydration can contribute to dry scalp conditions but is not the main cause of dandruff.

2. Which of the following is a functional group commonly found in alcohols?

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

Correct answer: B

Rationale: The hydroxyl functional group (OH) is commonly found in alcohols. The other choices are associated with different functional groups.

3. What is the outermost protective layer of the kidney?

A. Renal cortex
B. Renal medulla
C. Renal capsule
D. Renal pelvis

Correct answer: C

Rationale: The correct answer is C, renal capsule. The renal capsule is a tough fibrous layer that surrounds the kidney and provides protection. It helps maintain the shape of the kidney and serves as a barrier against infections and injuries. The renal cortex (A) is the outer region of the kidney where filtration occurs. The renal medulla (B) is the inner region of the kidney where urine is formed and collected. The renal pelvis (D) is a funnel-shaped structure that collects urine from the kidney and funnels it into the ureter. Therefore, the renal capsule is specifically the outermost protective layer of the kidney.

4. What is the scientific name for the common housefly?

A. Musca domestica
B. Drosophila melanogaster
C. Apis mellifera
D. Anopheles gambiae

Correct answer: A

Rationale: Rationale: - Musca domestica is the scientific name for the common housefly. This species is known for being a common pest found in and around human habitations. - Drosophila melanogaster (option B) is a species of fruit fly commonly used in genetic research. - Apis mellifera (option C) is the scientific name for the western honeybee. - Anopheles gambiae (option D) is a species of mosquito known for being a vector of malaria.

5. Which verb tense is most appropriate for this sentence: "By next week, _____ finished the project."

A. I will be finishing
B. I will have finished
C. I am finishing
D. I would finish

Correct answer: B

Rationale: Option B expresses a future event completed before another future point in time (next week).

6. A 10 kg box rests on a frictionless surface. A horizontal force of 20 N is applied to the box. What is the box's acceleration?

A. 0.5 m/sÂ²
B. 1 m/sÂ²
C. 2 m/sÂ²
D. 10 m/sÂ²

Correct answer: C

Rationale: Use Newton's second law, F = ma, where F is the net force, m is the mass, and a is the acceleration. Since there is no friction, the net force equals the applied force (20 N). Therefore, a = F/m = 20 N / 10 kg â‰ˆ 2 m/sÂ².