Nursing Elites

1. What are the differences between RNA and DNA?

• A. Both have the same structure and function.
• B. RNA is single-stranded, while DNA is double-stranded.
• C. RNA contains ribose sugar, while DNA contains deoxyribose sugar.
• D. RNA has adenine and guanine, while DNA has thymine and cytosine.

Correct answer: B

Rationale: Rationale: A) This statement is incorrect. RNA and DNA have different structures and functions. RNA is involved in protein synthesis and other cellular processes, while DNA stores genetic information. B) This statement is correct. RNA is typically single-stranded, while DNA is double-stranded, forming a double helix structure. C) This statement is correct. RNA contains ribose sugar in its backbone, while DNA contains deoxyribose sugar. D) This statement is incorrect. RNA contains adenine, guanine, cytosine, and uracil, while DNA contains adenine, guanine, cytosine, and thymine.

2. Which part of the neuron insulates and speeds up the transmission of nerve impulses along the axon?

• A. Dendrite
• B. Myelin sheath
• C. Synapse
• D. Cell body

Correct answer: b

Rationale: The correct answer is B: Myelin sheath. The myelin sheath is a fatty substance that surrounds the axon of a neuron, acting as an insulator to speed up the transmission of nerve impulses. It does this by creating gaps called nodes of Ranvier where the nerve impulses jump from one node to the next, allowing for faster signal conduction. Dendrites are branch-like extensions that receive signals from other neurons, the synapse is the junction between two neurons where neurotransmitters are released, and the cell body contains the nucleus and organelles of the neuron, but it is the myelin sheath that specifically insulates and speeds up the transmission of nerve impulses along the axon.

3. The network of vessels and ducts responsible for draining excess fluid and waste products from tissues is the:

• A. Circulatory system
• B. Digestive system
• C. Lymphatic system
• D. Respiratory system

Correct answer: C

Rationale: The correct answer is C: Lymphatic system. The lymphatic system is a network of vessels and ducts that play a crucial role in maintaining fluid balance in the body by draining excess fluid and waste products from tissues. Unlike the circulatory system (A), which primarily transports blood, the lymphatic system is specifically designed for this drainage function. The digestive system (B) is responsible for breaking down food and absorbing nutrients, while the respiratory system (D) is involved in the exchange of gases. Therefore, the lymphatic system is the correct answer for this question as it is uniquely tasked with managing tissue fluid balance and waste removal.

4. What property of a substance remains constant regardless of the amount of the substance present?

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

Correct answer: c

Rationale: Density remains constant for a specific substance regardless of the quantity present. It's the mass per unit volume and remains the same for a substance.

5. Which property of a substance refers to the force exerted on an object due to gravity?

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

Correct answer:

Rationale: Weight is the measure of the force exerted on an object due to gravity. It is calculated as mass multiplied by the acceleration due to gravity.

6. Melanin, the pigment responsible for skin color, is produced by

• A. Keratinocytes (These cells produce keratin)
• B. Melanocytes
• C. Sebocytes (These cells produce sebum)
• D. Langerhans cells (These cells are part of the immune system)

Correct answer: B

Rationale: The correct answer is B: Melanocytes. Melanin, the pigment responsible for skin color, is produced by melanocytes, which are specialized cells located in the skin's epidermis. Melanocytes transfer melanin to keratinocytes, the predominant cell type in the epidermis, where it provides protection against UV radiation. Sebocytes produce sebum, an oily substance that helps moisturize the skin and hair. Langerhans cells are a type of immune cell that play a role in the skin's immune response. Therefore, the correct answer is B as melanocytes are specifically responsible for producing melanin.

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