Nursing Elites

1. What is the difference between a pure substance and a mixture?

• A. Pure substances have fixed composition, mixtures don't.
• B. Mixtures have fixed composition, pure substances don't
• C. Pure substances are always solids, mixtures can be any state
• D. Pure substances are always elements, mixtures are always compounds

Correct answer: A

Rationale: Rationale: - Pure substances have a definite and constant composition, meaning they are made up of only one type of atom or molecule. This composition does not vary. - Mixtures, on the other hand, are composed of two or more substances physically combined. The components of a mixture can be present in varying proportions, leading to a variable composition. - Option A correctly distinguishes between pure substances and mixtures based on the fixed composition of pure substances and the variable composition of mixtures.

2. An object is moving in a circle at constant speed. Is there a net force acting on it?

• A. Yes, always
• B. No, never
• C. Only if its speed is changing
• D. Only if its direction is changing

Correct answer: A

Rationale: Even though the speed is constant, the direction is constantly changing, requiring a centripetal force to keep the object moving in a circle.

3. Parkinson's disease is a neurodegenerative disorder affecting which neurotransmitter?

• A. Dopamine
• B. Acetylcholine
• C. Serotonin
• D. Glutamate

Correct answer: A

Rationale: The correct answer is A: Dopamine. Parkinson's disease is characterized by a progressive loss of dopamine-producing neurons in the brain. Dopamine is a neurotransmitter responsible for transmitting signals in the brain that control movement and coordination. A decrease in dopamine levels leads to the typical motor symptoms of Parkinson's, such as tremors, rigidity, and bradykinesia. Acetylcholine (option B) is involved in muscle movement but is not primarily affected in Parkinson's disease. Serotonin (option C) and glutamate (option D) are neurotransmitters that play different roles in the brain and are not primarily associated with Parkinson's disease. Therefore, the correct neurotransmitter affected in Parkinson's disease is dopamine.

4. Differentiate between epithelial and connective tissue.

• A. Epithelial tissue is exclusively found in the lungs, while connective tissue supports tendons.
• B. Both are composed of cells, but epithelial tissue lines surfaces and glands, while connective tissue binds other tissues.
• C. Epithelial tissue is more vascularized, while connective tissue is responsible for muscle contraction.
• D. Epithelial tissue is the largest tissue type, while connective tissue is the smallest.

Correct answer: B

Rationale: Epithelial tissue covers surfaces and lines organs, while connective tissue provides support and structure throughout the body. Both are composed of cells, but their functions and locations differ.

5. Which vitamin plays a vital role in muscle function and helps prevent muscle weakness and fatigue?

• A. Vitamin A
• B. Vitamin B12
• C. Vitamin D
• D. Vitamin E

Correct answer: B

Rationale: The correct answer is B: Vitamin B12. Vitamin B12 plays a crucial role in muscle function by aiding in the production of red blood cells, which carry oxygen to the muscles. This vitamin also helps maintain the health of nerves that control muscle movements. Deficiency in vitamin B12 can lead to muscle weakness and fatigue due to decreased oxygen delivery and impaired nerve function in the muscles. Vitamin A is important for vision and immune function, Vitamin D is crucial for bone health, and Vitamin E is an antioxidant that protects cells from damage, but they do not have the same direct impact on muscle function as Vitamin B12.

6. Which vitamin requires intrinsic factor from the stomach for proper absorption?

• A. Vitamin A
• B. Vitamin C
• C. Vitamin D
• D. Vitamin B12

Correct answer: D

Rationale: The correct answer is D, Vitamin B12. Vitamin B12 requires intrinsic factor, a glycoprotein produced by the parietal cells in the stomach, for proper absorption in the small intestine. Intrinsic factor binds to B12 and facilitates its absorption in the ileum. Without intrinsic factor, the body cannot effectively absorb Vitamin B12, leading to deficiencies and various health issues. Vitamins A, C, and D do not require intrinsic factor for absorption and have different mechanisms for uptake and utilization within the body.

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