18 exam-style questions (62 marks) in three tiers. Try each one on paper first, then check the model answer and mark scheme.
Chapter 5 notes18 questions · 62 marks
Showing 18 of 18 questions
Recall and simple application
State where DNA is found in a cell and what a chromosome is made of.
Name the four bases of DNA and state which bases pair together.
Define a gene.
Name the three parts of a DNA nucleotide.
One strand of a DNA molecule reads G–T–A–C. Write the sequence of the complementary strand, naming the pairing rule you used.
Structured, exam-style
Describe the structure of a DNA molecule.
Explain how the base sequence of a gene specifies a polypeptide, and why genes are called the units of inheritance.
A DNA sample contains 180 bases, of which 30 are adenine. Calculate the number and percentage of each of the four bases in the sample.
Describe how the human insulin gene is used to make bacteria produce insulin.
Explain what is meant by a transgenic organism, and give one named example.
A gene segment reads A–T–G–C–C–A–T–T–G. (a) Write the complementary strand. (b) How many amino acids can this 9-base segment specify, and how did you work it out?
Explain why the universality of the genetic code makes gene transfer between species possible.
Data, evaluation and explanation
Explain why a bacterium is able to produce a protein normally made only by human cells, and state two advantages of manufacturing medicines this way.
A gene consists of 450 bases. Calculate the maximum number of amino acids in the polypeptide it codes for, and explain the reasoning behind the conversion.
Explain how complementary base pairing allows DNA to be copied accurately when a cell divides, and why this accuracy matters for the polypeptides the genes code for.
Discuss the benefits and ethical considerations of genetic engineering, using the production of human insulin in bacteria as your example, and give a reasoned conclusion.
Each haemoglobin polypeptide is about 570 amino acids long. (a) Calculate the minimum number of bases its gene must contain. (b) Explain how a single base change in that gene could alter the haemoglobin and harm the person carrying it.
A company engineers a rice variety that makes vitamin A, preventing blindness in deficient populations — but it patents the seeds, which farmers must buy fresh every year. Discuss one benefit, two ethical concerns, and give a reasoned conclusion.
Next step
A 30-mark paper set out like a school paper, with a separate mark scheme. Give yourself 40 min.
Question paper
30 marks · 40 min · 5 pages
5 multiple-choice questions and structured questions with answer lines. DNA, genes and chromosomes; nucleotide and double-helix structure; complementary base pairing; genes coding polypeptides; gene transfer; transgenic organisms and insulin production; benefits and ethics of genetic engineering.
Mark scheme
PROAnswers · Marking points · 3 pages
Model answers with a mark for each creditworthy point — for marking at home or in class.