Lesson 3.8.4.1.1

3.8.4.1.1 Recombinant DNA and transformation of host cells Quiz: AQA Biology, Unit 8

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

In partnership with Revision Ninja

Lesson 3.8.4.1.1, Recombinant DNA and transformation of host cells: 20 multiple choice questions for the AQA Biology (7402), Unit 8: The control of gene expression, written with Revision Ninja.

Host it live on the board and students join with a game code on their own devices, or revise alone with Free Play. The answers are revealed in the game.

Host this setFree Play

The 20 questions

  1. Recombinant DNA technology involves:

    • Breeding two organisms that are closely related to one another in order to produce offspring with a fixed set of desirable traits
    • Copying of mRNA into protein directly, without any DNA template, as occurs in the cytoplasm of every eukaryotic cell
    • Transfer of fragments of DNA from one organism or species to another
    • Removal of all DNA from a cell so that the cell can be grown without any genetic material for use in tissue culture experiments

  2. Why can DNA transferred from one species be translated in the recipient organism?

    • The genetic code is universal, as are transcription and translation mechanisms
    • The DNA is converted into a different genetic code first
    • Recipient cells always lack their own ribosomes
    • Recipient cells always translate DNA directly without mRNA

  3. Which enzyme converts mRNA into complementary DNA (cDNA)?

    • RNA polymerase
    • Reverse transcriptase
    • DNA polymerase
    • Restriction endonuclease

  4. What do restriction enzymes do in recombinant DNA technology?

    • Break down proteins into amino acids
    • Copy DNA by making new strands
    • Cut DNA at specific base sequences
    • Join DNA fragments together

  5. What is a gene machine?

    • An enzyme that removes introns from pre-mRNA during splicing, so that the mature mRNA leaves the nucleus ready for translation
    • A machine that copies genes in a cell nucleus during each division, so that every daughter cell receives an identical set of genes
    • A ribosome that makes proteins from the codons of an mRNA molecule, which is the site of translation in the cytoplasm of every cell
    • A device that creates a gene artificially from a known nucleotide sequence

  6. Why are promoter and terminator regions added to DNA fragments?

    • So that the inserted gene can be transcribed in the host cell
    • So that the fragment is broken down in the host cell
    • So that the fragment can be copied by PCR only
    • So that the fragment can be removed from a vector

  7. Which enzyme joins DNA fragments into a vector?

    • Restriction endonuclease
    • Ligase
    • Reverse transcriptase
    • Helicase

  8. A human gene is inserted into a bacterium, which then makes the human protein. Why does this work?

    • Bacteria always make human proteins without DNA
    • Bacteria use human ribosomes to translate the gene
    • Human genes are converted to bacterial genes by a restriction enzyme
    • The genetic code is universal, so the bacterial ribosomes translate the human gene

  9. Why is cDNA often preferred to genomic DNA when inserting a eukaryotic gene into a bacterium?

    • cDNA cannot be inserted into any host cell
    • cDNA is always cut by the host restriction enzyme
    • cDNA has no introns, so the bacterium can express the gene
    • cDNA contains more introns than genomic DNA

  10. What are marker genes used for in recombinant DNA technology?

    • To make the vector larger for easier handling in the laboratory, so that it can be seen under a microscope during cloning work
    • To remove introns from the inserted gene during cloning, so that the mature mRNA can be made directly from the vector sequence
    • To speed up the rate of translation in the host cell, so that the inserted gene produces more protein in each minute of growth
    • To identify cells that have taken up the vector and so are genetically modified

  11. What is the role of a vector in recombinant DNA technology?

    • To make restriction enzymes in the host
    • To carry the DNA fragment into host cells
    • To destroy the DNA fragment after transfer
    • To replace the host ribosomes

  12. What is meant by transformation of host cells?

    • Conversion of host cells into pluripotent stem cells by the recombinant DNA, which then allows the host cells to form any tissue
    • Destruction of host cells by a vector carrying a lethal gene, which kills the cells so that the recombinant DNA can be recovered
    • Removal of the nucleus from host cells by enzymes, so that the recombinant DNA can be inserted directly into the cytoplasm
    • Uptake of recombinant DNA by host cells, so their genetic material changes

  13. Restriction enzymes and ligases are used together to:

    • Break down the vector after use
    • Insert DNA fragments into vectors
    • Convert DNA into protein
    • Copy the vector using mRNA

  14. Which method creates a DNA fragment without cutting an existing DNA molecule?

    • Restriction enzyme digestion of a whole genome, which cuts the existing DNA molecule at specific sites to release the required fragment
    • Creating the gene in a gene machine from a nucleotide sequence
    • Culturing bacteria on agar plates containing antibiotic, which selects only the cells that have taken up a plasmid carrying the gene
    • Splicing of introns from pre-mRNA in the nucleus, which removes non-coding sequences from the transcript before the mRNA is exported

  15. A company wants to sell genetically modified seed and patents the modified gene. Which financial concern is most often raised?

    • Patents make all seeds cheaper for farmers each year, because competition between companies drives the price of every crop seed down
    • Patents prevent any gene from being inserted into a crop, so no company can ever create a modified seed that farmers could later use
    • Patents stop any seed from being sold to farmers, which means that the modified crop is never planted outside the laboratory
    • Farmers may have to buy new seed each season, creating a dependence on the company

  16. Which argument best balances humanitarian and environmental considerations of genetically modified crops?

    • GM crops should always be grown because they have no ecological effects
    • GM crops may increase food supply in poor regions, but long-term ecological effects must be assessed before use
    • GM crops are irrelevant to humanitarian concerns because they are used only in rich countries
    • GM crops should never be grown because all gene transfers are harmful

  17. How does recombinant DNA technology relate to gene therapy?

    • A functional copy of a gene can be introduced into a patient's cells to correct a faulty gene
    • Gene therapy removes all DNA from a patient's cells and replaces it with a copy of the genome from a healthy donor of the same age
    • Gene therapy involves the reverse transcription of proteins back into DNA, so that the body's proteins can be stored in the nucleus
    • Gene therapy only uses restriction enzymes to destroy genes that are expressed too strongly, so no new DNA is ever introduced into cells

  18. Put these steps in the most likely order: 1 cut the gene fragment with restriction enzyme, 2 join it into a plasmid vector, 3 transform host bacteria, 4 select GM cells using a marker. Which sequence is correct?

    • 1, 2, 3, 4
    • 4, 1, 2, 3
    • 2, 1, 3, 4
    • 1, 3, 2, 4

  19. Why must a vector carry both a promoter and a marker gene?

    • The promoter copies the vector during each cell division, and the marker removes introns from the inserted gene before it is expressed
    • The promoter allows transcription of the inserted gene, and the marker identifies cells that took up the vector
    • The promoter destroys the inserted gene before it can be transcribed
    • The promoter and marker both stop translation of the inserted gene, so that the protein is only made after the cell has been selected

  20. Why do ethical issues arise in the use of recombinant DNA in agriculture?

    • Ethics only apply to medicine and never to agriculture, since crops and animals are not able to be affected by the methods used on them
    • Ownership, environmental impact and effects on farmers and consumers must be weighed
    • There are no ethical issues because all organisms are equal in value, so no one needs to consider the effects of changing their genes
    • Ethics apply only to bacteria used in laboratories, because all larger organisms are regulated by agriculture ministries instead

All AQA Biology quizzes