1. Which of the following cell organelles is responsible for producing ATP, the primary

energy source for cellular activities?

A. Mitochondria

B. Golgi apparatus

C. Endoplasmic reticulum

D. Nucleus

Answer: A. Mitochondria

Rationale: Mitochondria are known as the powerhouses of the cell as they produce ATP

through cellular respiration.

2. Which of the following neurotransmitters is responsible for transmitting signals across

synapses in the nervous system?

A. Dopamine

B. Serotonin

C. Acetylcholine

D. GABA

Answer: C. Acetylcholine

Rationale: Acetylcholine is the primary neurotransmitter responsible for transmitting

signals across synapses in the nervous system.

3. The endocrine system is responsible for:

A. Regulating blood glucose levels

B. Controlling body temperature

C. Digesting food

D. Maintaining bone structure

Answer: A. Regulating blood glucose levels

Rationale: The endocrine system produces hormones that regulate various physiological

processes, including blood glucose levels.

4. Which of the following structures is responsible for pumping oxygen-rich blood to the

rest of the body?

A. Left atrium

B. Left ventricle

C. Right atrium

D. Right ventricle

Answer: B. Left ventricle

Rationale: The left ventricle is responsible for pumping oxygen-rich blood from the heart

to the rest of the body.