Nursing Elites

1. How does the human eye focus light?

• A. Cornea
• B. Iris
• C. Lens
• D. Retina

Correct answer: C

Rationale: The human eye focuses light by adjusting the shape of its lens. The lens changes shape to allow the eye to focus on objects at different distances, a process known as accommodation. The cornea is the transparent outer covering of the eye that helps to focus light but does not change shape like the lens. The iris controls the size of the pupil to regulate the amount of light entering the eye. The retina is the light-sensitive layer at the back of the eye that receives and processes images but does not adjust the focus of light.

2. Which of the following is a special property of water?

• A. Water does not easily flow through phospholipid bilayers.
• B. A water molecule's oxygen atom does not allow fish to breathe.
• C. Water is highly cohesive, which explains its high melting point.
• D. Water cannot self-hydrolyze and decompose into hydrogen and oxygen.

Correct answer: C

Rationale: Water is highly cohesive, meaning it is attracted to itself due to its hydrogen bonding properties. This cohesion is the reason why water has a high melting point compared to other liquids of similar molecular weight. It is crucial for the existence of life on Earth as it allows water to remain a liquid within a wide range of temperatures, providing a stable environment for biological processes to occur. Choices A, B, and D are incorrect. Water's cohesive property does not directly relate to its ability to flow through phospholipid bilayers, assist fish in breathing, or self-hydrolyze into hydrogen and oxygen.

3. Which type of muscle tissue contracts involuntarily and is found in organs like the heart and intestines?

• A. Skeletal muscle
• B. Cardiac muscle
• C. Smooth muscle
• D. All of the above

Correct answer: C

Rationale: Smooth muscle is the type of muscle tissue that contracts involuntarily and is found in organs like the heart and intestines. Skeletal muscle is responsible for voluntary movements, like those involved in skeletal system actions. Cardiac muscle is found in the heart and contracts involuntarily, but it is distinct from smooth muscle. The heart's muscle is specialized and forms the myocardium, which is not the same as the smooth muscle found in organs like the intestines. Therefore, the correct answer is C) Smooth muscle.

4. Which of the following is responsible for maintaining the body's circadian rhythm?

• A. Thyroid gland
• B. Pineal gland
• C. Pancreas
• D. Hypothalamus

Correct answer: B

Rationale: The pineal gland is responsible for maintaining the body's circadian rhythm by producing melatonin. Melatonin is a hormone that helps regulate the sleep-wake cycle and is essential in controlling the body's internal clock. The thyroid gland, although important for metabolism, is not directly involved in regulating circadian rhythms. The pancreas plays a role in blood sugar regulation through insulin production, not in controlling circadian rhythms. The hypothalamus is involved in regulating various bodily functions, but the pineal gland is specifically responsible for the circadian rhythm.

5. Which property of a substance refers to its ability to be stretched into thin wires without breaking?

• A. Conductivity
• B. Viscosity
• C. Ductility
• D. Malleability

Correct answer: C

Rationale: Ductility is the property of a substance that allows it to be stretched into thin wires without breaking. This property is distinct from the other options provided. Conductivity refers to the ability to conduct electricity or heat, viscosity refers to a liquid's resistance to flow, and malleability refers to the ability of a substance to be hammered or rolled into thin sheets. Therefore, the correct answer is 'Ductility.'

Similar Questions