Genetic code

Question 1

What is transcription

Answer 1

The process of forming complementary copies of mRNA from sequences of DNA that code for a particular polypeptide or protein

Question 2

Why use mRNA

Answer 2

Keep DNA in nucleus so always available for transcription, prevents it from becoming damaged in the cytoplasm

Question 3

Basic stages of Transcription

Answer 3

1- helicaze breaks H bonds
2- polymerase forms PDE bonds
3-Complementary base pairing
4- When RNA reaches stop triplet code it detaches

Question 4

how is mRNA modified

Answer 4

Introns (non coding sections) are removed and the exons are ‘spliced’ back together to produce the coding sequence required for the specific polypeptide or protein

Question 5

3 features of the genetic code

Answer 5

1- non overlapping
2- degenerate: 64 sequences coding for 20 amino acids -allowing a degree of duplication
3- it is a universal code

Question 6

What is the DNA code

Answer 6

The linear order of the nitrogenous bases along one of the 2 backbone strands