1. What is the largest lymphatic vessel in the body?

A. Jugular vein
B. Thoracic duct
C. Subclavian vein
D. Aorta

Correct answer: B

Rationale: The correct answer is B: Thoracic duct. The thoracic duct is the largest lymphatic vessel in the body, responsible for draining lymph from the lower half of the body, the left side of the head and neck, and the left arm. The jugular vein (A) and subclavian vein (C) are both blood vessels, not lymphatic vessels. The aorta (D) is the largest artery in the body, responsible for carrying oxygenated blood away from the heart. Understanding the anatomy of the lymphatic system is crucial for understanding the circulation and immune functions of the body.

2. Which element is used in semiconductors like computer chips and solar panels?

A. Germanium
B. Silicon
C. Gallium
D. Arsenic

Correct answer: B

Rationale: Silicon's unique properties allow it to be manipulated to conduct or not conduct electricity, making it ideal for various electronic applications.

3. Which of the following is a strong base commonly used in cleaning products?

A. Sodium hydroxide (NaOH)
B. Ammonium hydroxide (NHâ‚„OH)
C. Calcium hydroxide (Ca(OH)â‚‚)
D. Potassium hydroxide (KOH)

Correct answer: A

Rationale: Sodium hydroxide is a strong base commonly used in cleaning products. The other choices are also bases but are not as strong as sodium hydroxide.

4. What is the Doppler effect, and how does it explain the shift in frequency of sound waves perceived by an observer?

A. It only affects light waves, not sound waves.
B. It's the change in wave speed due to medium density.
C. It's the perceived change in frequency due to relative motion.
D. It's the bending of waves due to different mediums.

Correct answer: C

Rationale: The Doppler effect describes how the perceived frequency of a wave changes depending on the relative motion between the source and observer. For example, an approaching siren sounds higher pitched due to compressed wavefronts, while a receding siren sounds lower due to stretched wavefronts.

5. Which hormone is responsible for stimulating the development of sex organs and secondary sex characteristics during puberty?

A. Growth hormone
B. Testosterone (in males) and Estrogen (in females
C. Insulin
D. Thyroid hormone

Correct answer: B

Rationale: The correct answer is B: Testosterone (in males) and Estrogen (in females). During puberty, the release of these sex hormones plays a crucial role in the development of sex organs and secondary sex characteristics. Testosterone is responsible for male characteristics like facial hair, deepening of the voice, and muscle growth, while Estrogen contributes to female features such as breast development and the widening of hips. Growth hormone primarily regulates overall growth and development, while Insulin is involved in glucose metabolism and Thyroid hormone controls metabolism and energy levels. Therefore, the correct choice is B as Testosterone and Estrogen are specifically responsible for the changes seen during puberty.

6. A decorative globe has a diameter of 25cm. What is its total surface area?

A. 1570 sq cm
B. 1963 sq cm
C. 2513 sq cm
D. 3142 sq cm

Correct answer: B

Rationale: Use the formula for surface area of a sphere: 4 * Ï€ * (radius)^2, where radius is half the diameter. Calculate the radius (12.5cm) and substitute: 4 * Ï€ * (12.5cm)^2 â‰ˆ 1963 sq cm.