Biology · Unit 18

Biotechnology

Engineering life in the lab

Biotechnology is what happens when the molecular machinery from earlier units becomes something you can use deliberately. Restriction enzymes cut, ligases join, PCR copies and sequencing reads - and with those four capabilities most of modern genetics becomes possible.

The unit covers genetic engineering, cloning, CRISPR and the applications in medicine and agriculture, including the parts that are genuinely contested rather than settled.

This unit breaks down into 20 short steps and 120 questions, starting at difficulty 1 and building to 3. Below you can see exactly what it covers, how the path is structured, and worked examples with explanations.

Steps: 20
Questions: 120
Difficulty: 1-3

What this unit covers

Genetic Engineering
PCR and DNA Sequencing
CRISPR and Gene Editing
Cloning
Biotech in Medicine and Agriculture

Where this fits

The last unit in the Biology track for a reason - it assumes Molecular Biology and DNA and Genetics throughout.

Where people slip

Cloning means at least three different things - copying a gene, copying a cell line, copying an organism - and questions rarely say which. Check what is being copied before answering.

How the unit is structured

Biotechnology runs as 20 short steps that unlock in order. 15 are practice rounds and 5 are challenge rounds that pull together everything before them. Questions start at difficulty 1 and climb to 3 as you progress.

Step 1 · easierStep 20 · harder

Challenge rounds

Example questions

30 real questions from this unit, with the answer and the reason behind it, grouped by what they practise. There are 120 in the unit altogether.

Biotech in Medicine and Agriculture

Multiple choiceLevel 1
1. How is most human insulin for diabetics made today?
- By genetically modified bacteriacorrect
- By collecting it from human donors
- By a purely chemical reaction with no cells
- By grinding up plants
Insulin is produced by genetically modified bacteria that carry the human insulin gene, replacing older animal sources.
Choose all that applyLevel 2
2. Which of these are real uses of genetically modified organisms? Select all that apply.
- Bacteria making human insulincorrect
- Crops resistant to insect pestscorrect
- Rice enriched with vitamin Acorrect
- A car running on petrol
GM bacteria make insulin, and GM crops can resist pests or be enriched with vitamins; a petrol car is not a GMO use.
Fill the blankLevel 2
3. In breadmaking, yeast ferments the sugars in the dough and releases ____ gas, which makes the dough rise.
- carbon dioxidecorrect
- oxygen
- nitrogen
- hydrogen
Bubbles of carbon dioxide from yeast fermentation get trapped in the dough and make it rise; the small amount of alcohol bakes off.
Guess the numberLevel 2
4. In roughly which year was the first genetically engineered human insulin (Humulin) approved for use by diabetics?
Answer: 1982
Human insulin made by genetically modified bacteria was approved around 1982, replacing insulin extracted from animals.
Match the pairsLevel 2
5. Match each biotechnology product to what it is used for.
Answer: Insulin = Treating diabetes; Golden rice = Preventing vitamin A deficiency; Bt crops = Resisting insect pests; PCR test = Detecting a virus
Each of these products has a specific real-world job in medicine or farming.
Picture questionLevel 2
6. 🌾 Golden rice was genetically engineered to contain more of which nutrient?
- Vitamin A (from beta-carotene)correct
- Vitamin C
- Extra sugar
- Vitamin B12
Golden rice makes beta-carotene, which the body turns into vitamin A, to help fight vitamin A deficiency.

CRISPR and Gene Editing

Build the sentenceLevel 2
7. Build the sentence that describes how CRISPR finds its target.
Answer: The guide RNA directs Cas9 to the target gene
A guide RNA base-pairs with the target sequence and directs the Cas9 nuclease to that specific gene.
Fact or fibLevel 2
8. Editing the genes of a human embryo raises serious ethical concerns because the changes can be passed to future generations.
Answer: True
Changes made to an embryo affect every cell and can be inherited, which is why embryo editing is heavily debated.
Fill the blankLevel 2
9. ____ therapy treats an inherited disorder by adding a healthy copy of a faulty gene to a patient's cells.
- Genecorrect
- Heat
- Light
- Water
Gene therapy delivers a working gene into a patient to make up for a faulty or missing one.
Multiple choiceLevel 2
10. CRISPR is best described as a tool that lets scientists do what?
- Edit specific genes by cutting DNA at chosen placescorrect
- Copy an entire genome in minutes
- Grow new organs from scratch
- Turn plants into animals
CRISPR lets scientists edit genes precisely, adding, removing or changing specific pieces of DNA.
Spell itLevel 2
11. Spell the gene-editing tool, nicknamed genetic scissors, that uses the Cas9 enzyme.
Answer: CRISPR
CRISPR is the gene-editing system often called genetic scissors because it cuts DNA at chosen sites.
Odd one outLevel 3
12. Three of these are things CRISPR-Cas9 can be used to do. Which is the odd one out?
- Knock out a faulty gene
- Correct a disease-causing mutation
- Insert a new gene at a chosen site
- Translate messenger RNA into a proteincorrect
CRISPR edits DNA by cutting, correcting or inserting genes; translating messenger RNA into protein is done by ribosomes, not CRISPR.

Cloning

Multiple choiceLevel 1
13. Why was Dolly the sheep so famous?
- She was the first mammal cloned from an adult body cellcorrect
- She was the first genetically modified animal
- She was the oldest sheep ever recorded
- She was the first animal in space
Dolly, born in 1996, was the first mammal ever cloned from an adult body cell.
True or falseLevel 1
14. Identical twins are natural clones because they share the same DNA.
Answer: True
Identical twins form from one fertilised egg that splits, so they are genetically identical natural clones.
Fill the blankLevel 2
15. Once one transgenic animal that makes a useful drug is created, a whole herd of identical producers can be made quickly by ____ that animal.
- cloningcorrect
- vaccinating
- milking
- sequencing
Cloning the founder animal by nuclear transfer yields many genetically identical individuals that all make the medicinal protein.
Guess the numberLevel 2
16. In which year was Dolly the sheep, the first cloned mammal, born?
Answer: 1996
Dolly the sheep was born in 1996 at the Roslin Institute in Scotland.
Tap the pairsLevel 2
17. Match each cloning term to its meaning.
Answer: Clone = Genetically identical copy; Dolly = First cloned mammal; Tissue culture = Cloning many plants; Surrogate = Carries the cloned embryo
These are the key terms used when describing how clones are produced.
Sequence recallLevel 3
18. Recall the order of steps used to clone Dolly the sheep (somatic cell nuclear transfer).
Answer: Take a body cell from the sheep being cloned -> Remove the nucleus from a donor egg cell -> Put the body-cell nucleus into the empty egg -> Stimulate the egg to divide into an embryo -> Implant the embryo into a surrogate mother
A body-cell nucleus is placed into an emptied egg cell, stimulated to divide, and the embryo is implanted in a surrogate.

Genetic Engineering

Multiple choiceLevel 1
19. What does genetic engineering involve?
- Transferring a gene from one organism into anothercorrect
- Breeding two animals of the same species
- Feeding an organism a special diet
- Exposing an organism to bright light
Genetic engineering moves a gene from one organism into another so the new organism makes a wanted protein or gains a trait.
Fact or fibLevel 2
20. Some restriction enzymes leave short single-stranded overhangs called sticky ends.
Answer: True
Sticky ends are unpaired overhangs that let a cut gene pair up neatly with a plasmid cut by the same enzyme.
Fill the blankLevel 2
21. In genetic engineering, a ____ carries a gene into a host cell.
- vectorcorrect
- receptor
- solvent
- pigment
A vector, often a plasmid or a virus, is the carrier that delivers a gene into a host cell.
Odd one outLevel 2
22. Which of these is NOT a step in genetic engineering?
- Cutting out a gene with a restriction enzyme
- Inserting the gene into a plasmid vector
- Sealing the DNA with DNA ligase
- Waiting for the species to evolve the trait naturallycorrect
Genetic engineering cuts out a gene, inserts it into a vector, and seals it with ligase; it does not wait for a trait to evolve naturally.
Build the sentenceLevel 3
23. Build the sentence describing how mRNA vaccines protect their fragile genetic material.
Answer: lipid nanoparticles carry the fragile mRNA into cells
Lipid nanoparticles shield the easily-degraded mRNA and help it enter cells, where ribosomes translate it into antigen.
Match the pairsLevel 3
24. Match each enzyme or molecule to its job in genetic engineering.
Answer: Restriction enzyme = Cuts DNA at recognition sites; DNA ligase = Joins DNA fragments together; Reverse transcriptase = Makes cDNA from mRNA; Taq polymerase = Copies DNA during PCR
Restriction enzymes cut DNA, ligase joins fragments, reverse transcriptase makes cDNA from mRNA, and Taq polymerase copies DNA during PCR.

PCR and DNA Sequencing

Multiple choiceLevel 1
25. What does PCR do?
- Makes many copies of a piece of DNAcorrect
- Cuts DNA into small pieces
- Reads the order of the bases
- Joins two organisms together
PCR (polymerase chain reaction) makes many copies of a chosen piece of DNA from a very small starting sample.
Build the sentenceLevel 2
26. Build the sentence about a famous sequencing project.
Answer: The Human Genome Project sequenced all human DNA
The Human Genome Project sequenced all of the DNA in the human genome, finishing in 2003.
Fill the blankLevel 2
27. In PCR the mixture is first heated to about 95C to ____ the DNA by breaking the hydrogen bonds between the two strands.
- denaturecorrect
- ligate
- translate
- methylate
Heating to ~95C denatures the DNA, separating the double helix into two single-stranded templates.
Put in orderLevel 2
28. Put the three stages of one PCR cycle in the order they happen.
Answer: Denaturation at 95C separates the strands -> Annealing at about 55C binds the primers -> Extension at about 72C as Taq polymerase adds nucleotides
Each cycle runs denaturation at 95C, then annealing of primers around 55C, then extension by Taq polymerase around 72C.
Fact or fibLevel 3
29. Fact or fib: DNA polymerase in PCR can only extend a new strand in the 5' to 3' direction.
Answer: True
This is a fact - DNA polymerases add nucleotides only to the free 3' end, so synthesis always runs 5' to 3'.
Guess the numberLevel 3
30. PCR heats the DNA to roughly what temperature to separate the two strands (denaturation)?
Answer: 95 degrees C
The denaturation step heats DNA to about 95 degrees C, breaking the hydrogen bonds so the strands separate.

Where these questions come from. Each unit starts as a plan of the concepts it should cover and the difficulty it should span. Questions are written against that plan with AI assistance, then checked by a validator that rejects anything without a single defensible answer, an explanation, or plausible wrong options. How we write questions sets out the whole process, and corrections are fixed in the bank and reach the site and the app the same day.

How you practise

This unit mixes 17 different question formats, so you are recalling and applying rather than recognising the same layout every time.

Build the sentence
Choose all that apply
Fact or fib
Fill the blank
Guess the number
Listen and choose
Match the pairs
Multiple choice
Odd one out
Picture question
Put in order
Sequence recall
Sort into groups
Spell it
Tap the pairs
True or false
Type the answer

Practise Biotechnology

120 questions across 20 steps. Start with step one and crawl at your own pace.

Play this unit

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