Select the correct statements from the following
A. The presence of Thymine at the place of Uracil gives more stability to DNA
B. Both nucleic acids, i.e., DNA and RNA mutate
C. DNA is dependent on RNA for synthesis of proteins
D. RNA mutate at slower rate than DNA
E. DNA is better genetic material
Choose the correct answer from the options given below
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → A, B, C and E only
DNA and RNA can both carry genetic information. The statements compare how well each does the job of a genetic material.
A. The presence of Thymine at the place of Uracil gives more stability to DNA — True. DNA has thymine where RNA has uracil, and this makes DNA more stable.
B. Both nucleic acids, i.e., DNA and RNA mutate — True. Both can mutate, that is, undergo a change in their base sequence.
C. DNA is dependent on RNA for synthesis of proteins — True. DNA cannot make proteins directly; it is first transcribed into mRNA, which is translated.
D. RNA mutate at slower rate than DNA — False. The rate is reversed. RNA is unstable and mutates faster, which is why RNA viruses evolve fast.
E. DNA is better genetic material — True. DNA is chemically less reactive and structurally more stable than RNA, so it is the better store of genetic information.
NCERT Extract:
Properties of Genetic Material (DNA Versus RNA) – “… In fact, the presence of thymine at the place of uracil also confers additional stability to DNA. (Detailed discussion about this requires understanding of the process of repair in DNA, and you will study these processes in higher classes.) Both DNA and RNA are able to mutate. In fact, RNA being unstable, mutate at a faster rate. Consequently, viruses having RNA genome and having shorter life span mutate and evolve faster. RNA can directly code for the synthesis of proteins, hence can easily express the characters. DNA, however, is dependent on RNA for synthesis of proteins.”
Summary – “… Though DNA and RNA both function as genetic material, but DNA being chemically and structurally more stable is a better genetic material.”