Nursing Elites

1. Which valve prevents backflow into the atrium when the ventricles contract?

• A. Pulmonary valve
• B. Tricuspid valve
• C. Mitral valve
• D. Aortic valve

Correct answer: B

Rationale: The tricuspid valve (right atrioventricular valve) prevents backflow into the right atrium when the right ventricle contracts. This valve ensures that blood flows in the correct direction, preventing regurgitation into the atrium. The pulmonary valve is responsible for preventing backflow into the right ventricle from the pulmonary artery. The mitral valve prevents backflow into the left atrium, and the aortic valve prevents backflow into the left ventricle from the aorta. Therefore, the correct answer is the tricuspid valve as it specifically addresses the scenario of backflow into the atrium during ventricular contraction.

2. What are the three main types of RNA?

• A. Messenger RNA (mRNA), ribosomal RNA (rRNA), and transfer RNA (tRNA)
• B. DNA, RNA, and protein
• C. Adenine, guanine, cytosine, and thymine
• D. Deoxyribose, ribose, and phosphate

Correct answer: A

Rationale: - Messenger RNA (mRNA) carries genetic information from the DNA in the nucleus to the ribosomes in the cytoplasm for protein synthesis. - Ribosomal RNA (rRNA) is a structural component of ribosomes, which are the cellular machinery responsible for protein synthesis. - Transfer RNA (tRNA) is responsible for bringing amino acids to the ribosome during protein synthesis. Options B, C, and D are incorrect: - Option B lists DNA, RNA, and protein, which are biomolecules but not the three main types of RNA. - Option C lists nitrogenous bases (adenine, guanine, cytosine, and thymine) found in DNA, not types of RNA. - Option D lists components of nucleotides (deoxyribose, ribose, and phosphate), which are building blocks of nucleic

3. What type of bone is the kneecap (patella)?

• A. Long bone
• B. Short bone
• C. Flat bone
• D. Irregular bone

Correct answer: C

Rationale: The correct answer is C: Flat bone. The kneecap (patella) is classified as a flat bone. Flat bones are thin, flattened bones that provide protection and offer a broad surface for muscle attachment. The patella fits this description as it is a flat, triangular bone located in front of the knee joint, protecting the knee and providing attachment points for muscles like the quadriceps. Choice A, long bone, is incorrect as long bones are typically found in the arms and legs, not in the knee area. Choice B, short bone, is incorrect as short bones are cube-shaped and are not characteristic of the patella. Choice D, irregular bone, is incorrect as irregular bones have complex shapes and do not apply to the flat, triangular structure of the patella.

4. What is the name of the structure that packages DNA in eukaryotic cells?

• A. Nucleosome
• B. Chromatin
• C. Histone
• D. Centromere

Correct answer: A

Rationale: - A nucleosome is the basic structural unit of DNA packaging in eukaryotic cells. It consists of DNA wrapped around a core of histone proteins. - Chromatin refers to the complex of DNA and proteins found in the nucleus of a eukaryotic cell, including nucleosomes. - Histones are the proteins around which DNA is wrapped to form nucleosomes. - Centromere is a region of a chromosome where the two sister chromatids are joined and to which spindle fibers attach during cell division.

5. Which of the following is LEAST likely to be found in a human cell's genes?

• A. Sequences of amino acids to be transcribed into mRNA
• B. Lethal recessive traits like sickle cell anemia
• C. Mutated DNA
• D. DNA that codes for proteins the cell doesn't use

Correct answer: D

Rationale: Human cells typically contain genes that code for proteins necessary for the cell's functions. DNA that codes for proteins the cell doesn't use would be an inefficient use of the cell's resources. Therefore, it is less likely to be found in a human cell's genes. Options A, B, and C are more commonly associated with genes found in human cells. Choice A refers to the genetic information needed for protein synthesis, while choice B involves traits that can be present in the gene pool. Mutated DNA (choice C) can also be found in human cells as a result of genetic alterations. However, DNA that codes for proteins not utilized by the cell would be redundant and not typically retained in the genome.

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