Nursing Elites

1. Which macromolecule serves as the repository of genetic information in all living organisms?

• A. Ribonucleic acid (RNA)
• B. Deoxyribonucleic acid (DNA)
• C. Protein
• D. Carbohydrate

Correct answer: B

Rationale: - DNA is the macromolecule that serves as the repository of genetic information in all living organisms. It carries the genetic instructions necessary for the growth, development, functioning, and reproduction of organisms. - RNA (option A) is involved in various cellular processes, including protein synthesis, but DNA is the primary molecule responsible for storing genetic information. - Proteins (option C) are essential for various cellular functions but do not serve as the primary repository of genetic information. - Carbohydrates (option D) are important for energy storage and structural support but do not store genetic information.

2. Which muscular chamber of the heart receives blood from the body and pumps it to the lungs?

• A. Right atrium
• B. Left atrium
• C. Right ventricle
• D. Left ventricle

Correct answer: A

Rationale: The correct answer is the right atrium. The right atrium receives deoxygenated blood from the body through the superior and inferior vena cava. It then pumps this deoxygenated blood to the lungs via the pulmonary artery for oxygenation. The left atrium receives oxygenated blood from the lungs and pumps it to the left ventricle. The right ventricle receives oxygen-poor blood from the right atrium and pumps it to the lungs. The left ventricle receives oxygenated blood from the left atrium and pumps it to the rest of the body.

3. What is the main component that gives bones their rigidity and hardness?

• A. Collagen
• B. Calcium phosphate
• C. Cartilage
• D. Ligaments

Correct answer: B

Rationale: Calcium phosphate is the main component that gives bones their rigidity and hardness. It combines with calcium hydroxide to form hydroxyapatite crystals, which provide strength and structure to bones. Collagen, on the other hand, provides flexibility and tensile strength. Cartilage is a type of connective tissue found in joints, and ligaments are fibrous tissues that connect bones to other bones, but they do not contribute to the rigidity and hardness of bones.

4. Which of the following is the neutral subatomic particle found in the nucleus of an atom?

• A. Electron
• B. Proton
• C. Neutron
• D. Positron

Correct answer: C

Rationale: The correct answer is C, Neutron. Neutrons are subatomic particles found in the nucleus of an atom that have no charge. They have a mass of approximately 1 atomic mass unit (amu). The number of neutrons in an atom's nucleus contributes to the mass number of the atom, which is the total number of protons and neutrons in the nucleus. Choice A, Electron, is incorrect as electrons are negatively charged particles found outside the nucleus. Choice B, Proton, is incorrect as protons are positively charged particles found in the nucleus. Choice D, Positron, is incorrect as positrons are positively charged antiparticles of electrons and are not typically found in the nucleus of an atom.

5. Which of the following components is found in DNA?

• A. Uracil
• B. Deoxyribose
• C. Guanine
• D. Phosphate group

Correct answer: B

Rationale: The correct answer is B: Deoxyribose. DNA is composed of nucleotides containing deoxyribose sugar, phosphate group, and nitrogenous bases (adenine, thymine, guanine, and cytosine). Deoxyribose is the sugar component specific to DNA, while ribose is found in RNA. Guanine (choice C) is a nitrogenous base present in both DNA and RNA. Uracil (choice A) is a nitrogenous base specific to RNA, replacing thymine found in DNA. The phosphate group (choice D) is an essential part of nucleotides in both DNA and RNA, providing the backbone structure for the nucleic acid chains.

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