Use Fig. 4.1 to explain in what ways the structure of mRNA is different from the structure of DNA.
Using Fig. 4.2 and Table 4.1, state what happens to the amino acid sequence in the first part of the $\beta$ chain of haemoglobin if the base pair at position 6 is deleted.
Using Fig. 4.2 and Table 4.1, state what happens to the amino acid sequence in the first part of the $\beta$ chain of haemoglobin if the three base pairs at positions 7, 8 and 9 are deleted.
Complete Table 4.2 by placing a tick (✓) beside the features that apply to each process. Use a cross (✗) for features that do not apply. The first row has already been done for you.
Telomeres are regions at the ends of chromosomes. Describe the function of telomeres.
Describe the role of ribosomes in protein synthesis.