Nursing Elites

1. What is the smallest bone in the human body?

• A. Stapes (Middle ear bone)
• B. Patella (Kneecap)
• C. Phalanges (Finger bones)
• D. Ribs

Correct answer: A

Rationale: The correct answer is A: Stapes (Middle ear bone). The stapes, located in the middle ear, is indeed the smallest bone in the human body. Despite its small size, the stapes is vital for hearing as it transmits and amplifies sound vibrations, contributing significantly to auditory perception. Choices B, C, and D are incorrect. The patella (kneecap) is the largest sesamoid bone in the human body, not the smallest bone. Phalanges are the bones in fingers and toes, not the smallest bone overall. Ribs are long bones that protect the chest cavity, not the smallest bone in the body.

2. Which of the following nucleic acids carries amino acids to organelles called ribosomes, where the amino acids are linked one by one to produce a polypeptide?

• A. DNA
• B. mRNA
• C. rRNA
• D. tRNA

Correct answer: D

Rationale: tRNA is the correct answer as it carries amino acids to the ribosomes during protein synthesis. Transfer RNA (tRNA) plays a crucial role in protein synthesis by bringing specific amino acids to the ribosome according to the mRNA sequence. Once at the ribosome, the amino acids are linked together to form a polypeptide chain. This process is essential for the creation of proteins in the cell, highlighting the significance of tRNA in the translation process. Choice A, DNA, is incorrect as DNA does not directly participate in protein synthesis. Choice B, mRNA, is incorrect as mRNA carries the genetic information from DNA to the ribosome but does not directly carry amino acids. Choice C, rRNA, is incorrect as ribosomal RNA is a component of the ribosome structure and is involved in protein synthesis but does not carry amino acids like tRNA.

3. What checkpoint mechanism ensures all chromosomes are attached to the spindle fibers before anaphase begins?

• A. Prometaphase
• B. Metaphase
• C. Cyclin degradation
• D. Sister chromatid cohesion

Correct answer: A

Rationale: A) Prometaphase is the correct answer because it is the stage of mitosis where all chromosomes are attached to the spindle fibers before anaphase begins. During prometaphase, the nuclear envelope breaks down, allowing the spindle fibers to attach to the kinetochores of the chromosomes. This attachment is necessary for proper chromosome alignment and segregation during anaphase. B) Metaphase is incorrect because it is the stage where chromosomes are aligned at the metaphase plate but do not necessarily have all spindle fibers attached. C) Cyclin degradation is incorrect because it is a regulatory mechanism that controls the progression of the cell cycle but is not specifically related to ensuring all chromosomes are attached to spindle fibers. D) Sister chromatid cohesion is incorrect because it refers to the physical connection between sister chromatids that is maintained until anaphase, but it does not ensure that all chromosomes are attached to spindle fibers.

4. In a food chain, which trophic level captures energy from the sun?

• A. Decomposers
• B. Carnivores
• C. Producers
• D. Omnivores

Correct answer: C

Rationale: Producers, such as plants, algae, and some bacteria, are the organisms in a food chain that capture energy from the sun through the process of photosynthesis. They convert sunlight into chemical energy, which is then passed on to other organisms in the food chain. Producers are at the base of the food chain and form the foundation for all other trophic levels to obtain energy. Decomposers (option A) break down organic matter, carnivores (option B) consume other animals, and omnivores (option D) consume both plants and animals, but they do not directly capture energy from the sun.

5. Which vitamin is synthesized in the skin upon exposure to sunlight?

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

Correct answer: C

Rationale: Vitamin D is synthesized in the skin upon exposure to sunlight. When the skin is exposed to sunlight, a form of cholesterol in the skin is converted into vitamin D3 (cholecalciferol) through a series of chemical reactions. Vitamin D plays a crucial role in calcium absorption and bone health. Choice A, Vitamin A, is not synthesized in the skin upon exposure to sunlight; it is obtained through dietary sources. Choice B, Vitamin C, is not synthesized in the skin upon exposure to sunlight either. Vitamin C is obtained through dietary sources like fruits and vegetables. Choice D, Vitamin E, is not synthesized in the skin upon exposure to sunlight. Vitamin E is a fat-soluble vitamin that acts as an antioxidant and is obtained through dietary sources like nuts, seeds, and vegetable oils.

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