Question

Read the sources given and answer any four from the questions given below:

In prokaryotes, the DNA is circular, has only one chromosome and present in the cytoplasm. In eukaryotes, the DNA is linear, packed in a number of chromosomes and mainly confined to the nucleus. DNA or deoxyribonucleic acid is a long polymer of nucleotides. DNA is the genetic material for most organisms while RNA is the genetic material in some viruses. DNA is composed of three components, a phosphate group, a deoxyribose sugar and a nitrogenous base. There are two types of bases purines and pyrimidines. Adenine (A) and Guanine (G) are purines while Cytosine (C), Thymine (T) and Uracil (U) are pyrimidines. DNA has A, G, C and T while in RNA thymine is replaced by uracil. The bases are paired by Chargaff's rule by which A pairs with T and C pairs with G. DNA being more stable than RNA. DNA is said to be better for storage of genetic information, hence better genetic material. RNA has ribose sugar which has 2'-ОН group present in every nucleotide. It is a reactive group and makes RNA catalytic and easily degradable. Hence comparatively DNA is chemically less reactive and structurally more stable than RNA.

1. The type ofnuclear matter present in prokaryotes
   1. circular RNA in nucleus
   2. circular RNA in cytoplasm
   3. linear DNA in cytoplasm
   4. circular DNA in cytoplasm
2. RNA is a polynucleotide having the following components
   1. phosphate group, A,U,T,G and deoxyribose sugar
   2. phosphate group, A,C,T,U and deoxyribose sugar
   3. phosphate group, U,C,T,G and ribose sugar
   4. phosphate group, A,C,U,G and ribose sugar
3. Which of the following statements is not true for RNА?
   1. highly stable
   2. contains base uracil
   3. genetic material in some viruses
   4. has 2-OH group in nucleotides
4. Why is DNA considered to be better genetic material than RNA because it is
   1. more easily degradable
   2. structurally more stable
   3. catalytic in nature
   4. contains bases A, T, C and G
5. RNA is the genetic material in
   1. eukaryotes
   2. prokaryotes
   3. viruses
   4. both (b) and (c)

Answer 1

1. circular DNA in cytoplasm
2. phosphate group, A,C,U,G and ribose sugar
3. has 2-OH group in nucleotides
4. structurally more stable
5. viruses