Nursing Elites

1. Water is capable of dissolving many substances that organisms need to carry out life functions. Which of the properties of water listed below is responsible for its ability to dissolve important nutrients like ionic salt compounds?

• A. adhesion
• B. cohesion
• C. high specific heat
• D. high polarity

Correct answer: D

Rationale: The property of water that is responsible for its ability to dissolve important nutrients like ionic salt compounds is its high polarity. Water is a polar molecule with a positive and negative end, which allows it to attract and surround individual ions from salt compounds, causing them to dissociate and dissolve in water. This property makes water an excellent solvent for various substances necessary for life functions. Adhesion refers to the ability of water molecules to stick to other substances, cohesion is the attraction between water molecules themselves, and high specific heat is the amount of heat energy required to raise the temperature of water. While these properties are important characteristics of water, they are not directly responsible for its ability to dissolve ionic salt compounds.

2. Which blood component is responsible for the production of antibodies?

• A. Platelets
• B. Red blood cells
• C. White blood cells
• D. Plasma cells

Correct answer: C

Rationale: White blood cells, specifically B lymphocytes or B cells, are responsible for producing antibodies as part of the immune response. When the body encounters foreign substances (antigens), B cells are activated to differentiate into plasma cells, which then produce antibodies to target and neutralize the antigens. Platelets are involved in blood clotting and not in antibody production. Red blood cells are primarily responsible for carrying oxygen in the blood and do not produce antibodies. Plasma cells are actually differentiated B cells that produce antibodies, but the question asks for the blood component responsible for the production of antibodies, which is the white blood cells.

3. The gradual change in a species over time is called:

• A. Adaptation
• B. Evolution
• C. Speciation
• D. Natural selection

Correct answer: B

Rationale: - Adaptation refers to the process by which a species becomes better suited to its environment over time. While adaptation is a component of evolution, it specifically refers to the changes that help a species survive and reproduce in its environment. - Speciation is the process by which new species arise from a single ancestral species. It involves the evolution of reproductive isolation between populations. - Natural selection is a mechanism of evolution where individuals with advantageous traits are more likely to survive and reproduce, leading to the increase in frequency of those traits in a population. - Evolution is the gradual change in a species over time, encompassing all the processes such as adaptation, speciation, and natural selection that drive these changes.

4. Which vitamin is crucial for calcium absorption and synthesized in the skin upon sun exposure?

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

Correct answer: C

Rationale: The correct answer is Vitamin D. Vitamin D is essential for calcium absorption as it helps regulate calcium and phosphorus levels in the body. When the skin is exposed to sunlight, UVB rays convert a compound in the skin to vitamin D. This vitamin is vital for maintaining bone health and ensuring the overall calcium balance in the body. Choices A, B, and D are incorrect. Vitamin A is important for vision and immune function, Vitamin C is essential for collagen synthesis and immune function, and Vitamin E is an antioxidant that helps protect cells from damage by free radicals. However, none of these vitamins are primarily responsible for calcium absorption and synthesized in the skin upon sun exposure.

5. Where does the digestion of food start?

• A. Esophagus
• B. Stomach
• C. Small intestine
• D. Mouth

Correct answer: D

Rationale: The correct answer is the mouth. Digestion begins in the mouth where mechanical breakdown occurs through chewing, and chemical breakdown begins with saliva. Enzymes in saliva start breaking down carbohydrates, initiating the digestion process. The esophagus is responsible for transporting food from the mouth to the stomach and does not play a role in the digestion process. The stomach continues the digestion process after the food leaves the mouth. The small intestine is primarily responsible for absorbing nutrients from the digested food, rather than being the initial site of digestion.

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