1. Which term describes the ability of a muscle to return to its original length and shape after being stretched or contracted?

A. Contractility
B. Elasticity
C. Extensibility
D. Excitability

Correct answer: b

Rationale: The correct answer is B: "Elasticity." Elasticity is the term that describes the ability of a muscle to return to its original length and shape after being stretched or contracted. Contractility refers to the muscle's ability to contract forcefully, extensibility is the ability of a muscle to be stretched without being damaged, and excitability is the ability of a muscle to respond to stimuli. In this context, elasticity specifically pertains to the muscle's ability to bounce back to its original form, making it the most appropriate term in relation to the question.

2. A pizza has a diameter of 40cm. What is its perimeter (circumference)?

A. 62.8cm
B. 125.5cm
C. 125.6cm
D. 251.2cm

Correct answer: C

Rationale: Multiply the diameter by Ï€: perimeter = Ï€ * diameter = Ï€ * 40cm â‰ˆ 125.6cm (Note: Ï€ â‰ˆ 3.14)

3. What is the term for the number of moles of solute per liter of solution?

A. Molarity
B. Molality
C. Normality
D. Concentration

Correct answer: A

Rationale: Molarity is defined as the number of moles of solute per liter of solution. The other choices are different concentration units.

4. Which neurotransmitter is associated with mood regulation, sleep, and appetite?

A. Acetylcholine
B. Dopamine
C. Serotonin
D. GABA (Gamma-aminobutyric acid)

Correct answer: c

Rationale: The correct answer is C: Serotonin. Serotonin is a neurotransmitter that plays a crucial role in mood regulation, sleep, and appetite. It is often referred to as the 'feel-good' neurotransmitter because it helps regulate mood and emotional well-being. Serotonin is also involved in controlling sleep patterns and appetite, making it essential for maintaining a healthy balance in these areas. Acetylcholine is mainly associated with muscle movement and memory, while dopamine is linked to pleasure and reward pathways. GABA is an inhibitory neurotransmitter that helps reduce neuronal excitability. Therefore, serotonin is the neurotransmitter most closely associated with mood regulation, sleep, and appetite.

5. The small intestine is where most of the chemical digestion and nutrient absorption occur. What is the finger-like projection in the small intestine that increases its surface area for absorption?

A. Rugae
B. Villi
C. Microvilli
D. All of the above

Correct answer: D

Rationale: The correct answer is D, 'All of the above.' The finger-like projection in the small intestine that increases its surface area for absorption is primarily the villi and microvilli. Villi are small, finger-like projections that line the inner wall of the small intestine, while microvilli are even smaller projections on the surface of the villi. Both structures significantly increase the surface area of the small intestine, allowing for more efficient absorption of nutrients. Rugae, on the other hand, are folds in the stomach lining that help with expansion when the stomach is full. Therefore, the rugae are not directly related to the increased surface area for absorption in the small intestine, making options A and B incorrect choices. Overall, options A, B, and C are all related to the structure of the small intestine but serve different functions, so the most appropriate answer is D, 'All of the above.'

6. Which phenomenon explains the formation of rainbows in the sky?

A. Diffraction
B. Interference
C. Refraction and dispersion of sunlight by water droplets.
D. Reflection from clouds

Correct answer: C

Rationale: Refraction and dispersion of sunlight by water droplets in the atmosphere separate white light into its constituent colors, creating the rainbow phenomenon.