The Genetic Code And Mutations

Question 1

3 features of the genetic code

Answer 1

Non overlapping
Degenerate
Universal

Question 2

The genetic code

Answer 2

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

Question 3

Non overlapping

Answer 3

Each codon is read in sequence separate from the codon before and after it: aka, no nitrogenous base is shared between multiple codons
So each codon has its own 3 bases

Question 4

Degenerate

Answer 4

Some amino acids are encoded for by more than one triplet and thus codon

Question 5

Why is the genetic code degenerate?

Answer 5

There are 20 amino acids but 64 possible codons (eg combos of A U C G)
So for every amino acid, there is more than 1 codon which can encode for it

Question 6

Universal

Answer 6

In all organisms, the same specific base triplets encode for same amino acids

Question 7

How is the fact that the genetic code is universal provide evidence for evolution?

Answer 7

Because it shows how in all organisms, the code has been preserved from a common ancestor (eg LUCA)

Question 8

What is a mutation?

Answer 8

When there is a change in the base sequence of DNA in terms of base

Question 9

When do mutations usually occur?

Answer 9

During DNA replications due to to a copying error

Question 10

2 types of mutation

Answer 10

Substitution
Deletion

Question 11

Substitution

Answer 11

When one base is substituted for another

Question 12

Does substitution mutation mean the protein synthesised will be faulty?

Answer 12

Not necessarily because the substituted base which leads to a different codon could still encode for same amino acid (genetic code is degenerate) possibility it changes still exists though
And has no effect on rest of amino acids encoded for

Question 13

Deletion

Answer 13

One base is completely removed from the DNA sequence

Question 14

Does a deletion mutation mean the protein synthesised will be different?

Answer 14

Yes: