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Answer: ASet 2: Cross-Text Connections
Explanation
PASSAGE
Text 1 The central dogma of molecular biology states that genetic information flows in one direction: from DNA to RNA to Protein. This was long considered an absolute rule. Text 2 The discovery of retroviruses like HIV upended this dogma. Retroviruses use an enzyme called reverse transcriptase to copy their RNA genome back into DNA, proving that the flow of information can be bidirectional.
What is the significance of the retrovirus mentioned in Text 2?
A. It provides a biological exception that disproves the unidirectionality of the central dogma.✓ Correct
B. It proves DNA does not exist.
C. It shows that proteins make DNA.
D. It confirms the central dogma.
Detailed Explanation
Text 1: DNA -> RNA (One way). Text 2: RNA -> DNA (Reverse). Significance: Disproves unidirectionality.
Key Evidence:
• "upended this dogma"
• "bidirectional"
Why others are wrong: B (Copy back into DNA.), C (RNA to DNA.), D (Upended it.).