Nursing Elites

1. Which element is used in fire extinguishers to smother flames by displacing oxygen?

• A. Nitrogen
• B. Carbon dioxide
• C. Helium
• D. Argon

Correct answer: B

Rationale: Carbon dioxide extinguishes flames by depriving them of oxygen, preventing the chemical reaction that sustains the fire.

2. What is the breakdown product of ATP (adenosine triphosphate) that provides energy for muscle contraction?

• A. Glucose
• B. Creatine phosphate
• C. ADP (adenosine diphosphate)
• D. Lactic acid

Correct answer: C

Rationale: The correct answer is C: ADP (adenosine diphosphate). During muscle contraction, ATP is broken down into ADP and inorganic phosphate, releasing energy that fuels the muscle contraction process. This energy release allows the muscle fibers to contract and perform work. Glucose is a source of energy that is broken down through cellular respiration to produce ATP but is not the direct breakdown product of ATP itself. Creatine phosphate is another energy storage molecule in muscles but is not the breakdown product of ATP. Lactic acid is produced during anaerobic respiration when there is a lack of oxygen, and it is not the primary energy source for muscle contraction. Therefore, ADP is the correct breakdown product of ATP that provides energy for muscle contraction.

3. Which of the following phases of mitosis is characterized by the separation of sister chromatids and their movement to opposite poles?

• A. Metaphase
• B. Anaphase
• C. Anaphase
• D. Cytokinesis

Correct answer: B

Rationale: Rationale: During anaphase of mitosis, the sister chromatids, which are duplicated copies of a chromosome, separate and move towards opposite poles of the cell. This movement is facilitated by the shortening of microtubules attached to the chromatids. As a result, each pole of the cell receives a complete set of chromosomes, ensuring that the daughter cells produced after cell division will have the correct number of chromosomes. Metaphase is characterized by the alignment of chromosomes at the cell's equator, not their separation. Telophase is the phase following anaphase, where the separated chromatids reach the opposite poles and nuclear envelopes start to form around them. Cytokinesis is the final stage of cell division, where the cytoplasm is divided to form two separate daughter cells.

4. A spring with a spring constant of 100 N/m is stretched 0.2 m from its equilibrium position. What is the potential energy stored in the spring?

• A. 2 J
• B. 4 J
• C. 8 J
• D. 20 J

Correct answer: B

Rationale: Potential energy in a spring is calculated as 1/2 * k * x², where k is the spring constant and x is the displacement from equilibrium. Therefore, the potential energy is 1/2 * 100 N/m * (0.2 m)² = 4 J.

5. 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: 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

6. What is the difference between a homozygous recessive genotype and a homozygous dominant genotype?

• A. Both have the same phenotype, but different genotypes.
• B. Both have the same genotype, but different phenotypes.
• C. Homozygous recessive has two dominant alleles, while homozygous dominant has two recessive alleles.
• D. Homozygous recessive has two identical recessive alleles, while homozygous dominant has two identical dominant alleles.

Correct answer: D

Rationale: Rationale: - Homozygous recessive genotype refers to an individual having two identical recessive alleles for a particular gene (e.g., rr for a trait where r represents the recessive allele). - Homozygous dominant genotype refers to an individual having two identical dominant alleles for a particular gene (e.g., RR for a trait where R represents the dominant allele). - The difference between the two genotypes lies in the specific alleles present in each case, with homozygous recessive having two recessive alleles and homozygous dominant having two dominant alleles. - This genetic difference results in different phenotypes being expressed, as the dominant allele typically masks the expression of the recessive allele in heterozygous individuals.

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