Nursing Elites

1. Which vitamin deficiency can lead to a condition called pernicious anemia, affecting vitamin B12 absorption in the digestive system?

• A. Vitamin A
• B. Vitamin B12 (cobalamin)
• C. Vitamin D
• D. Vitamin E

Correct answer: B

Rationale: Pernicious anemia is caused by a deficiency in vitamin B12 (cobalamin). Vitamin B12 is essential for the production of red blood cells and for the proper functioning of the nervous system. Pernicious anemia occurs when there is a lack of intrinsic factor, a protein produced in the stomach that is necessary for the absorption of vitamin B12 in the digestive system. Vitamin A, Vitamin D, and Vitamin E deficiencies do not lead to pernicious anemia. Vitamin A deficiency can cause night blindness and skin issues, Vitamin D deficiency can lead to rickets or osteomalacia, and Vitamin E deficiency can result in neurological problems and muscle weakness.

2. The tonsils and adenoids, located in the throat, are part of the:

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

Correct answer: A

Rationale: The tonsils and adenoids are part of the lymphatic system, not the respiratory, endocrine, or digestive systems. The lymphatic system plays a crucial role in the body's defense against infections and diseases by producing white blood cells and lymphatic fluid, which help in filtering harmful substances. The respiratory system is primarily responsible for breathing and gas exchange in the body, the endocrine system regulates hormones, and the digestive system is involved in the breakdown and absorption of nutrients from food. Therefore, the correct answer is the lymphatic system.

3. A rock has a mass of 3 grams (g) and a volume of 4 cm³. What is its density?

• A. 8.90 g/cm³
• B. 0.38 g/cm³
• C. 77.22 g/cm³
• D. 2.65 g/cm³

Correct answer: D

Rationale: Density is determined by the formula Density = Mass / Volume. For this rock, the mass is 3g, and the volume is 4 cm³. Applying the formula: Density = 3g / 4cm³ = 0.75 g/cm³. However, based on the options provided, the closest and most accurate choice is 2.65 g/cm³, corresponding to option D. Choice A, 8.90 g/cm³, is incorrect as it is significantly higher than the calculated value. Choice B, 0.38 g/cm³, and Choice C, 77.22 g/cm³, are also incorrect and do not match the correct calculation.

4. During embryonic development, most vertebrates exhibit structures called pharyngeal pouches. These pouches eventually develop into different structures in various vertebrate groups, such as the human jaw and inner ear. Pharyngeal pouches are an example of:

• A. Analogous structures with different evolutionary origins but similar functions
• B. Homologous structures with a common evolutionary origin but diverse functions
• C. Vestigial structures that no longer serve a vital function in some organisms
• D. Atavisms, the reappearance of a trait absent in recent generations

Correct answer: B

Rationale: Pharyngeal pouches in vertebrates are an example of homologous structures because they share a common evolutionary origin. Despite developing into different structures in various vertebrate groups, such as the jaw and inner ear in humans, these structures originated from the same ancestral feature. This concept of homology highlights the evolutionary relationship between different species and how structures can be modified over time to serve different functions while retaining a common origin. Choice A is incorrect because analogous structures have similar functions but different evolutionary origins, which does not apply to pharyngeal pouches. Choice C is incorrect as vestigial structures are remnants of features that were functional in ancestors but have reduced or lost their original function, which is not the case for pharyngeal pouches. Choice D is incorrect because atavisms refer to the reappearance of traits absent in recent generations, which is not the characteristic of pharyngeal pouches.

5. What is the rigid structure that provides shape and support to plant cells?

• A. Cell wall
• B. Plasma membrane
• C. Nucleus
• D. Cytoplasm

Correct answer: A

Rationale: The correct answer is the cell wall, as it is the rigid structure that provides shape and support to plant cells. The cell wall is located outside the plasma membrane and is primarily composed of cellulose, giving it its rigid nature. The plasma membrane (option B) is a semi-permeable membrane surrounding the cell that regulates the movement of substances in and out of the cell. The nucleus (option C) houses the cell's genetic material and controls cellular activities. Cytoplasm (option D) is the gel-like substance within the cell that surrounds organelles and where various cellular processes take place, but it does not provide the rigid structure and support that the cell wall does.

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