Nursing Elites

1. What is the process by which RNA molecules are modified after transcription but before translation?

• A. Replication
• B. Splicing
• C. Editing
• D. Packaging

Correct answer: B

Rationale: B) Splicing is the correct answer. Splicing is the process by which non-coding regions (introns) are removed from pre-mRNA, and the remaining coding regions (exons) are joined together to form mature mRNA. This modification occurs after transcription but before translation. A) Replication is incorrect as replication is the process by which DNA is copied to produce a new DNA molecule, not RNA modifications. C) Editing may involve RNA editing, but it is not commonly used to describe the modification of RNA molecules after transcription. D) Packaging is not the correct term as it refers to the condensation and organization of DNA into chromatin in eukaryotic cells, not the modification of RNA molecules.

2. Which of these body parts does not contain melanin?

• A. Hair
• B. Nails
• C. Skin
• D. Iris

Correct answer: D

Rationale: The iris is the colored part of the eye that determines the eye's color. Melanin is not present in the iris, unlike hair, nails, and skin. Melanin gives color to hair, nails, and skin, but not to the iris. Therefore, the correct answer is the iris (Choice D). Choices A, B, and C contain melanin and are incorrect.

3. Which blood type is considered a universal donor?

• A. A
• B. B
• C. AB
• D. O

Correct answer: D

Rationale: Blood type O is considered the universal donor because individuals with type O blood can donate red blood cells to individuals with any ABO blood type (A, B, AB, or O) without causing an adverse reaction. Type O blood lacks A or B antigens on the surface of red blood cells, minimizing the risk of an immune response when transfused into individuals with different blood types. Therefore, type O blood is in high demand for blood transfusions in emergency situations when the recipient's blood type is unknown or when there is a shortage of specific blood types. Choices A, B, and AB are not considered universal donors. Individuals with blood types A, B, or AB can only donate to individuals with compatible blood types to avoid adverse reactions since they have A and/or B antigens on the surface of their red blood cells, making them incompatible with all blood types.

4. What enzymes do lysosomes contain, leading to their nickname as the cell's 'suicide bags'?

• A. Hydrolytic enzymes
• B. Ligases (bonding enzymes)
• C. Transferases (molecule transfer)
• D. Oxidoreductases (redox reactions)

Correct answer: A

Rationale: Lysosomes are organelles filled with hydrolytic enzymes that break down proteins, nucleic acids, lipids, and carbohydrates. These enzymes aid in digesting cellular waste and foreign substances, hence the term 'suicide bags' due to their involvement in cell degradation and recycling. Ligases are enzymes that catalyze the joining of two large molecules by forming a new chemical bond, not present in lysosomes. Transferases are enzymes that catalyze the transfer of functional groups from one molecule to another, not found in lysosomes. Oxidoreductases are enzymes involved in oxidation-reduction reactions, which are not the primary function of lysosomes.

5. In aerobic respiration, how many ATP molecules are produced per molecule of FADH2?

• A. 1
• B. 2
• C. 3
• D. 4

Correct answer: B

Rationale: The correct answer is B: 2. During aerobic respiration, each molecule of FADH2 produces 2 ATP molecules. FADH2 enters the electron transport chain and contributes to the generation of ATP. Choice A (1), Choice C (3), and Choice D (4) are incorrect because FADH2 specifically yields 2 ATP molecules per molecule in the process of aerobic respiration.

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