Nursing Elites

1. Which of the following is a protein?

• A. cellulose
• B. hemoglobin
• C. estrogen
• D. ATP

Correct answer: B

Rationale: The correct answer is 'hemoglobin' because it is a protein that carries oxygen in the blood. Cellulose is a carbohydrate found in the cell walls of plants, not a protein. Estrogen is a hormone, not a protein. ATP (adenosine triphosphate) is a molecule that carries energy within cells, not a protein.

2. Which cellular structure is found in animal cells but not in plant cells?

• A. Centriole
• B. Cytoplasm
• C. Vacuole
• D. Golgi apparatus

Correct answer: A

Rationale: The correct answer is A, Centriole. Centrioles are found in animal cells but not in plant cells. They play a crucial role in organizing microtubules during cell division, aiding in the formation of the mitotic spindle. Plant cells lack centrioles; instead, they utilize microtubule organizing centers to perform similar functions during cell division. Choices B, C, and D are incorrect because cytoplasm is a part of both animal and plant cells, vacuoles are found in plant cells and some animal cells, and the Golgi apparatus is present in both types of cells.

3. Physical factors such as temperature and pH can alter enzyme activity because they have an effect on the enzyme's ___________.

• A. acidity
• B. shape
• C. chemistry
• D. substrate

Correct answer: B

Rationale: Physical factors such as temperature and pH can alter enzyme activity by affecting the enzyme's shape. Enzymes rely on their specific shapes to function properly and catalyze reactions. Any changes in temperature or pH can disrupt these shapes, causing the enzyme to become denatured and lose its functionality. Therefore, alterations in temperature and pH can impact enzyme activity by directly affecting their shapes. Choices A, C, and D are incorrect because while pH can affect acidity and chemical properties of the enzyme, and temperature can influence the enzyme-substrate interaction, the primary reason for enzyme activity alteration due to temperature and pH is the change in the enzyme's shape.

4. Cytosine and thymine are known as:

• A. Purines
• B. Pyrimidines
• C. Both
• D. None of the above

Correct answer: B

Rationale: Cytosine and thymine are known as pyrimidines because they have a single carbon ring structure. Purines, on the other hand, have a double-ring structure. Choice A ('Purines') is incorrect because purines have a double-ring structure, unlike cytosine and thymine. Choice C ('Both') is incorrect as it implies they are both purines and pyrimidines, which is not true. Choice D ('None of the above') is incorrect because cytosine and thymine are indeed pyrimidines.

5. How many phases are there in the process of mitosis?

• A. 2
• B. 3
• C. 4
• D. 5

Correct answer: C

Rationale: The correct answer is C: '4'. Mitosis consists of four phases: prophase, metaphase, anaphase, and telophase. These phases are crucial in the orderly division of the cell's genetic material. Choice A is incorrect because mitosis is a more complex process involving multiple phases. Choice B is incorrect as it is one phase short of the total phases in mitosis. Choice D is incorrect as mitosis does not consist of five phases.

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