Short answerEasy1 mark
Explain the abbreviation – DNA.
Topic: DNA
Previous-year question practice database
Answer
Exam answer
DEOXYRIBONUCLEIC ACID.
Explanation
Write it out in full; the abbreviation earns nothing.
The name describes the molecule: it is a NUCLEIC ACID (found in the nucleus and acidic) whose sugar is DEOXYRIBOSE — ribose with one oxygen atom removed.
THE CONTRAST WITH RNA, which follows from the name: RNA is RIBOnucleic acid, and its sugar is RIBOSE, which retains that oxygen. The difference of one oxygen atom is what the two names record.
DNA carries the hereditary information, arranged as a DOUBLE HELIX of two complementary strands — which is why it can copy itself accurately before every cell division.
Spelling matters here: DEOXYRIBONUCLEIC, one word.
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