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Gene Expression · Part 1 of 3
6 exam-style questions with model answers, plus 8 quick multi-choice questions — every question on this part of the standard, grouped by the 2 pages of notes they come from.
Write a full answer before you reveal the model one. That comparison is where the learning happens.
Name the three parts of a nucleotide, and state two differences between DNA and RNA.
Explain the difference between the coding strand and the template strand of DNA, and explain why the mRNA sequence matches the coding strand.
Discuss why the specific complementary base pairing rules of DNA are essential, considering what would happen to gene expression if bases could pair in any combination.
Define the terms triplet, codon and anticodon, and state what is meant by saying the genetic code is degenerate.
Explain why the genetic code must be read in groups of three bases rather than one or two, and explain one advantage of the code being degenerate.
Two mutations occur in the same gene. Mutation A changes a base but the polypeptide is unchanged. Mutation B changes a single base and the polypeptide produced is much shorter than normal. Discuss the likely nature of each mutation, and evaluate which is more likely to affect the organism's phenotype.