4: GENETICS - THE GENETIC CODE

Question 1

What is the genetic code?

Answer 1

the sequence of base triplets (codons) in mRNA which code for specific amino acids

Question 2

What are the 3 features of the genetic code?

Answer 2

• non-overlapping
• degenerate
• universal

Question 3

Explain what is meant by the genetic code being non-overlapping?

Answer 3

• the genetic code is a series of base triplets
• triplets don’t share their bases

Question 4

Explain what is meant by the genetic code being degenerate?

Answer 4

• there are more possible combinations of triplets than there are amino acids
• 20 amino acids but 64 possible triplets
• this means that some amino acids can be coded for by more than 1 base triplet (eg: tyrosine can be coded for by UAU/UAC)

Question 5

Explain what is meant by the genetic code being universal?

Answer 5

the same specific base triplets code for the same amino acids in all organisms (eg: UAU codes for tyrosine in all living organisms)