The table gives the amino acids specified by DNA triplets on the strand being studied. The letters P, Q and R represent different amino acids.
| DNA triplet | Amino acid |
|---|---|
| AAA | P |
| AAG | P |
| GGA | Q |
| GAA | R |
| CCT | Q |
An original DNA sequence is AAA GGA CCT.
Variant X is AAG GGA CCT.
Variant Y is AAA GAA CCT.
Assume these variants do not affect how much protein is made. Which prediction is best supported?
X changes the amino acid sequence; Y may change the protein's final shape.
X preserves the amino acid sequence; Y must preserve the protein's final shape.
X preserves the amino acid sequence; Y may change the protein's final shape.
X changes the amino acid sequence; Y must preserve the protein's final shape.
76 exam-style questions on AQA GCSE Biology 6.1 Reproduction, covering 6.1.1 Sexual and asexual reproduction, 6.1.2 Meiosis, 6.1.3 Advantages and disadvantages of sexual and asexual reproduction, 6.1.4 DNA and the genome, 6.1.5 DNA structure, 6.1.6 Genetic inheritance, 6.1.7 Inherited disorders, and 6.1.8 Sex determination. Each one has a worked solution and a mark scheme showing where the marks go.