Nursing Elites

1. Which type of muscle is found in the walls of hollow organs, such as the stomach and intestines, and is responsible for involuntary contractions to propel substances through the organs?

• A. Cardiac muscle
• B. Smooth muscle
• C. Skeletal muscle
• D. Striated muscle

Correct answer: B

Rationale: Smooth muscle is the correct answer. It is found in the walls of hollow organs like the stomach and intestines, where it performs involuntary contractions to move substances through these organs. Cardiac muscle, found in the heart, is responsible for pumping blood. Skeletal muscle is attached to bones and involved in voluntary movements. Striated muscle is a term often used interchangeably with skeletal muscle, which is responsible for voluntary movements but not typically found in the walls of hollow organs like the stomach and intestines.

2. Which of the following terms means close to the trunk of the body?

• A. Superficial
• B. Sagittal
• C. Proximal
• D. Distal

Correct answer: C

Rationale: The term 'proximal' means situated close to the point of attachment or the center of the body, such as close to the trunk. In anatomical terms, proximal is used to describe locations that are closer to the body's center or point of reference. 'Superficial' refers to something situated near the surface, 'sagittal' refers to a plane that divides the body into left and right portions, and 'distal' refers to a position away from the center or point of reference. Therefore, 'proximal' is the correct term to indicate a position close to the trunk of the body.

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. Which of the following is directly transcribed from DNA and represents the first step in protein synthesis?

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

Correct answer: C

Rationale: mRNA (messenger RNA) is directly transcribed from DNA in the nucleus during the process of transcription. It serves as a template for protein synthesis during translation in the cytoplasm. mRNA carries genetic information from the DNA to the ribosomes, where it determines the sequence of amino acids in a protein. Thus, mRNA represents the first step in protein synthesis as it carries the code from the DNA to be translated into a protein. Choice A, siRNA (small interfering RNA), is involved in post-transcriptional gene silencing and does not play a role in protein synthesis. Choice B, rRNA (ribosomal RNA), is a component of the ribosome and plays a structural and functional role in protein synthesis but is not directly transcribed from DNA. Choice D, tRNA (transfer RNA), is responsible for bringing amino acids to the ribosome during protein synthesis but is not directly transcribed from DNA.

5. Which of the following does not describe a general trait of macromolecules?

• A. They can exist as single chains.
• B. They can be branched.
• C. They all contain carbon, hydrogen, and phosphorus.
• D. They are all used by the body.

Correct answer: C

Rationale: The correct answer is C. While many macromolecules contain carbon, hydrogen, and phosphorus, not all of them do. For example, lipids, a type of macromolecule, may not contain phosphorus. Choice A and B describe structural features that macromolecules can exhibit, whether as single chains or branched forms. Choice D is incorrect as not all macromolecules are used by the body, such as synthetic polymers or certain non-digestible fibers.

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