1. The diaphragm is a dome-shaped muscle that plays a crucial role in breathing. When it contracts, what happens?

A. Air is expelled from the lungs.
B. The lungs expand to allow air intake.
C. The vocal cords vibrate to produce sound.
D. The trachea narrows to control airflow.

Correct answer: B

Rationale: The diaphragm is a dome-shaped muscle located beneath the lungs. When it contracts, it moves downward, creating more space in the chest cavity. This downward movement of the diaphragm allows the lungs to expand, which lowers the air pressure inside the lungs. As a result, air from the outside rushes in to equalize the pressure, leading to inhalation. Therefore, when the diaphragm contracts, it facilitates the intake of air into the lungs, making option B, 'The lungs expand to allow air intake,' the correct answer.

2. Which of the following represents a form of potential energy?

A. A moving car
B. A spinning top
C. A raised hammer
D. A rolling ball

Correct answer: c

Rationale: A raised hammer possesses potential energy due to its elevated position relative to the ground.

3. The endocrine system communicates through chemical messengers called:

A. Enzymes
B. Hormones
C. Antibodies
D. Neurons

Correct answer: B

Rationale: The correct answer is B: Hormones. The endocrine system communicates through hormones, which are chemical messengers produced by various glands in the body. These hormones are released into the bloodstream and travel to target organs or tissues to regulate a wide range of bodily functions. Enzymes (A) are biological molecules that catalyze chemical reactions, not chemical messengers for communication within the body. Antibodies (C) are involved in the immune system's response to foreign substances. Neurons (D) are part of the nervous system and communicate through electrical impulses rather than chemical messengers like hormones.

4. A triangular scarf has sides measuring 10cm, 12cm, and 15cm. What is its perimeter?

A. 27cm
B. 32cm
C. 37cm
D. 45cm

Correct answer: C

Rationale: Simply add the lengths of all sides: perimeter = side1 + side2 + side3 = 10cm + 12cm + 15cm = 37cm.

5. The beautiful flowers brightened the room. Which word is the adverb form of the adjective "beautiful"?

A. beautiful
B. beautifully
C. beautification
D. beautify

Correct answer: B

Rationale: Adverbs are formed from adjectives by adding "-ly" (usually).

6. What is the difference between active and passive immunity?

A. Active immunity is short-lived, while passive immunity is long-lasting.
B. Active immunity involves the body's own immune response, while passive immunity provides immediate protection through antibodies from another source.
C. Active immunity only protects against bacterial infections, while passive immunity works against both bacteria and viruses.
D. Passive immunity requires repeated vaccinations, while active immunity is a one-time process.

Correct answer: A

Rationale: The correct answer is A: "Active immunity involves the body's own immune response, while passive immunity provides immediate protection through antibodies from another source." Active immunity is long-lasting because it involves the body's immune system producing memory cells that remember specific pathogens, providing long-term protection. Passive immunity, on the other hand, is short-lived as it involves receiving pre-formed antibodies from an external source, such as through maternal transfer or injection of antibodies, which do not create memory cells for long-lasting protection.