1. Which structure in the respiratory system is responsible for preventing food and liquids from entering the trachea during swallowing?

A. Bronchi
B. Larynx
C. Alveoli
D. Pharynx

Correct answer: B

Rationale: The correct answer is B: Larynx. The larynx, also known as the voice box, is a crucial structure in the respiratory system responsible for preventing food and liquids from entering the trachea during swallowing. It contains the epiglottis, a flap of tissue that covers the trachea during swallowing to ensure that food and liquids are directed to the esophagus instead of entering the airway. The bronchi are the two main branches that carry air into the lungs, while alveoli are tiny air sacs where gas exchange occurs. The pharynx is a shared pathway for both air and food, located behind the oral and nasal cavities. Therefore, the larynx plays a vital role in protecting the respiratory system during swallowing.

2. What property of a substance remains constant regardless of changes in its shape or size?

A. Mass
B. Weight
C. Density
D. Volume

Correct answer: a

Rationale: Mass remains constant regardless of changes in an object's shape or size.

3. What part of speech is the underlined word in the sentence: "He felt a growing sense of unease"?

A. Verb
B. Noun
C. Adjective
D. Adverb

Correct answer: B

Rationale: "Sense" represents a concept or feeling, making it a noun here.

4. 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.

5. What property of a substance measures the amount of matter per unit volume?

A. Mass
B. Weight
C. Density
D. Volume

Correct answer: c

Rationale: Density measures the amount of matter (mass) per unit volume of a substance.

6. The part of the brain responsible for balance and coordination is the:

A. Cerebellum
B. Cerebrum
C. Hypothalamus
D. Thalamus

Correct answer: A

Rationale: The correct answer is A: Cerebellum. The cerebellum is the part of the brain responsible for balance and coordination. It receives information from the sensory systems, spinal cord, and other parts of the brain to coordinate voluntary movements such as posture, balance, and speech. The cerebrum (option B) is responsible for higher brain functions such as thinking and decision-making. The hypothalamus (option C) is involved in regulating basic biological needs such as hunger and thirst. The thalamus (option D) acts as a relay station for sensory information. Therefore, the cerebellum is the specific part of the brain that plays a crucial role in maintaining balance and coordination.