Nursing Elites

1. Which of the following is a characteristic of alkenes?

• A. They have a double bond between carbon atoms.
• B. They are saturated hydrocarbons.
• C. They contain only single bonds.
• D. They are derivatives of ammonia.

Correct answer: A

Rationale: Alkenes are hydrocarbons that contain at least one carbon-carbon double bond. This double bond is a key characteristic that distinguishes alkenes from other types of hydrocarbons. Option A correctly identifies this defining feature of alkenes, making it the correct answer. Choices B, C, and D are incorrect. Choice B is incorrect because alkenes are unsaturated hydrocarbons due to the presence of double bonds. Choice C is incorrect as alkenes do not contain only single bonds; they have at least one double bond. Choice D is incorrect because alkenes are not derivatives of ammonia; they are a distinct class of organic compounds with carbon-carbon double bonds.

2. Which of the following is the largest organ in the human body?

• A. Liver
• B. Brain
• C. Heart
• D. Skin

Correct answer: D

Rationale: The skin is the largest organ in the human body. It covers the entire body, serving as a protective barrier against pathogens, UV radiation, and physical damage. Additionally, the skin plays a crucial role in regulating body temperature and synthesizing vitamin D when exposed to sunlight. Choices A, B, and C are incorrect. The liver is the largest internal organ, the brain is the control center of the body, and the heart is a vital organ responsible for pumping blood throughout the body. However, none of these organs are the largest in terms of surface area or overall size.

3. What is the primary function of the liver in the digestive system?

• A. To absorb water
• B. To produce bile
• C. To store glucose
• D. To regulate metabolism

Correct answer: B

Rationale: The liver's main function in the digestive system is to produce bile. Bile helps in the digestion and absorption of fats by emulsifying them, breaking down large fat globules into smaller droplets that can be acted upon by digestive enzymes. Choices A, C, and D are incorrect because the liver's primary role in the digestive system is not to absorb water, store glucose, or regulate metabolism. While the liver does have roles in metabolism and glucose regulation, its key function in digestion is bile production.

4. Which hormone is responsible for lowering blood sugar levels?

• A. Glucagon
• B. Insulin
• C. Adrenaline
• D. Cortisol

Correct answer: B

Rationale: Insulin is the hormone responsible for lowering blood sugar levels. It is produced by the pancreas and facilitates the entry of glucose into cells, thereby reducing blood sugar levels. Glucagon, adrenaline, and cortisol have roles in increasing blood sugar levels through various mechanisms. Glucagon raises blood sugar levels by stimulating the liver to release stored glucose, adrenaline increases blood sugar in fight-or-flight responses, and cortisol raises blood sugar levels as part of the stress response. Therefore, in the context of lowering blood sugar levels, insulin is the correct answer.

5. Which of the following does not describe a general trait of macromolecules?

• A. They can exist as single chains.
• B. They can be branched.
• C. They all contain carbon, hydrogen, and phosphorus.
• D. They are all used by the body.

Correct answer: C

Rationale: The correct answer is C. While many macromolecules contain carbon, hydrogen, and phosphorus, not all of them do. For example, lipids, a type of macromolecule, may not contain phosphorus. Choice A and B describe structural features that macromolecules can exhibit, whether as single chains or branched forms. Choice D is incorrect as not all macromolecules are used by the body, such as synthetic polymers or certain non-digestible fibers.

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