DNA and RNA

Question 1

gene definition

Answer 1

a sequence of bases of a DNA molecule coding for a specific sequence of amino acids in a polypeptide chain and found in a particular locus on a chromosome

Question 2

structure of a DNA nucleotide

Answer 2

phosphate group, deoxyribose and either A, C, G or a T organic base

Question 3

structure of an RNA nucleotide

Answer 3

phosphate group, ribose and either A, C, G or a U organic base

Question 4

the difference between RNA and DNA

Answer 4

1. RNA is a single polypeptide chain whilst DNA is a double polypeptide chain
2. RNA has a ribose and DNA has a deoxyribose
3. RNA has A,C,G,U bases and DNA has A,C,T,G
4. RNA is made in the nucleus but found throughout the cell while DNA is found in the nucleus
5. RNA can come as either mRNA or tRNA

Question 5

What bond joins two DNA molecules

Answer 5

phosphodiester bonds

Question 6

what bonds form between bases of opposite strands

Answer 6

hydrogen bonds

Question 7

what is a triplet code

Answer 7

each amino acid is coded for by a sequence of 3 bases

Question 8

what is a non-overlapping code

Answer 8

where each base can only be in one triplet

Question 9

what is a degenerate code

Answer 9

one amino acid may be coded by more than one triplet

Question 10

what is a universal code

Answer 10

a triplet codes for the same amino acid in all different species