Launching your learning experience…
Detailed notes on Reproduction for Cambridge IGCSE Biology, covering key concepts, explanations, examples, and exam-focused revision points.
One parent, identical clones. Fast and reliable, but no variation — risky in changing environments.
Mapped to the Cambridge IGCSE 0610 syllabus (2026-2028).
One parent. Offspring are genetically identical copies (clones).
Definition. Asexual reproduction produces GENETICALLY IDENTICAL offspring from ONE parent. There's NO fusion of gametes.
Examples.
1. Binary fission (bacteria, some protoctists).
2. Budding (yeast, Hydra).
3. Runners (strawberries, spider plants).
4. Tubers (potatoes, dahlias).
5. Spores (fungi, mosses, ferns).
Worked qualitative. Why can a single bacterium become billions in 24 hours?
Cambridge tip. Always state 'genetically identical offspring' AND 'one parent'. Both phrases are key.
Fast and reliable, but offspring are identical — vulnerable to change.
Advantages:
Disadvantages:
Famous example: Irish potato famine (1845-1852).
Worked qualitative. Why do farmers SOMETIMES choose to grow asexually-reproduced crops?
Cambridge tip. When asked for advantages/disadvantages, give 2 of each WITH reasons. Cambridge marks each.
Verbatim phrases and definitions Cambridge mark schemes credit.
Asexual reproduction appears Paper 4 (3-5 marks: define, examples, pros/cons). Examiner reports flag students forgetting 'genetically identical' and offering vague 'no variation' instead of explaining why that's a disadvantage.
Sources: Cambridge IGCSE Biology 0610 syllabus 2026-2028 (16.1); 0610/42 Oct/Nov 2024 — Q14 (asexual reproduction); 0610 Examiner Reports 2022-2024. Last reviewed 2026-05-07.
Step-by-step solutions to past-paper-style questions on asexual reproduction, written exactly the way a tutor would explain them at the board.
Question
Define asexual reproduction and give two examples.
Step-by-step solution
Step 1
Asexual reproduction is a process that produces genetically identical offspring from one parent, without the fusion of gametes.
Step 2
Example 1: binary fission in bacteria (a cell divides into two identical cells).
Step 3
Example 2: a potato plant producing new plants from tubers (or a strawberry plant from runners).
Answer
Asexual reproduction produces genetically identical offspring from one parent, with no gamete fusion. Examples: binary fission in bacteria; tubers in potatoes.
Question
State whether each describes asexual or sexual reproduction: (a) offspring are genetically identical to the parent; (b) two gametes fuse; (c) only one parent is needed; (d) offspring show variation.
Step-by-step solution
Step 1
(a) Genetically identical offspring → asexual.
Step 2
(b) Two gametes fuse → sexual.
Step 3
(c) Only one parent → asexual.
Step 4
(d) Offspring show variation → sexual.
Answer
(a) Asexual; (b) sexual; (c) asexual; (d) sexual.
Examiner tip
Asexual = one parent, identical offspring. Sexual = two gametes fuse, varied offspring.
Question
Give two advantages and two disadvantages of asexual reproduction.
Step-by-step solution
Step 1
Advantage 1: it is fast and only one parent is needed, so no mate has to be found.
Step 2
Advantage 2: if the parent is well suited to the environment, all the offspring will be too (they are identical).
Step 3
Disadvantage 1: there is no genetic variation, so the population cannot adapt if conditions change.
Step 4
Disadvantage 2: if a disease can affect one individual, it can affect them all, so the whole population is at risk.
Answer
Advantages: fast, no mate needed; offspring suited to the environment. Disadvantages: no variation, so cannot adapt; whole population vulnerable to the same disease.
Question
Explain why the offspring produced by asexual reproduction are genetically identical to the parent.
Step-by-step solution
Step 1
Asexual reproduction involves only one parent and does not involve the fusion of gametes.
Step 2
The new individuals are produced by mitosis, in which a cell divides to make genetically identical cells.
Step 3
Because mitosis copies the parent's DNA exactly, the offspring receive an exact copy of the parent's genes.
Step 4
So the offspring are clones of the parent — genetically identical to it and to each other.
Answer
There is only one parent and no gamete fusion; the offspring are made by mitosis, which copies the DNA exactly, so they are genetically identical clones of the parent.
Examiner tip
The key reasons: one parent, no fusion of gametes, produced by mitosis (exact DNA copy).
Question
Explain why asexual reproduction is an advantage in a stable, favourable environment but a disadvantage if the environment changes.
Step-by-step solution
Step 1
In a stable, favourable environment, the parent is well suited to the conditions.
Step 2
Because the offspring are identical to the parent, they are also well suited, and many can be produced quickly to take advantage of the good conditions.
Step 3
However, if the environment changes (e.g. a new disease or a change in temperature), all the offspring have the same genes and the same weakness.
Step 4
With no variation, none may be able to survive the new conditions, so the whole population could be wiped out.
Answer
In a stable environment, identical offspring are all well suited and can be produced quickly. But if the environment changes, the lack of variation means the whole population may be unable to survive.
Examiner tip
The trade-off is variation: none is needed in a stable environment, but its absence is dangerous when conditions change.
Question
A fruit grower takes cuttings from a plant that produces excellent fruit, rather than growing new plants from seed. Explain the advantage and one possible disadvantage.
Step-by-step solution
Step 1
Taking cuttings is a form of asexual reproduction, so the new plants are genetically identical to the parent.
Step 2
This means they will all produce the same excellent fruit, which growing from seed (sexual reproduction) could not guarantee, because the offspring would vary.
Step 3
It is also fast and reliable, producing many identical good plants.
Step 4
The disadvantage is that the plants have no genetic variation, so if a disease or pest affects one, it could destroy the whole crop.
Answer
Cuttings produce identical plants that all give the same good fruit, quickly and reliably — unlike seeds, which vary. The drawback is no variation, so the whole crop is vulnerable to the same disease.
Examiner tip
The advantage is uniformity/keeping the desirable feature; the disadvantage is vulnerability due to no variation.
High-scoring sample answers for asexual reproduction on the Cambridge IGCSE 0610 paper, with examiner-style notes mapping each response to the mark scheme and assessment objectives.
Define asexual reproduction. (1 mark)
Model answer
Asexual reproduction is a process resulting in genetically identical offspring from one parent (without the fusion of gametes).
Why this scores
One mark for 'genetically identical offspring from one parent'.
Give one advantage and one disadvantage of asexual reproduction. (2 marks)
Model answer
Advantage: it is fast and only one parent is needed (no mate required). Disadvantage: the offspring show no genetic variation, so the population cannot adapt to a changing environment.
Why this scores
One mark each: any valid advantage (fast / one parent / offspring suited to environment) and disadvantage (no variation / vulnerable to disease).
Explain why offspring produced by asexual reproduction are genetically identical to the parent. (3 marks)
Model answer
Asexual reproduction involves only one parent and no fusion of gametes. The offspring are produced by mitosis, which makes an exact copy of the parent's DNA. So the offspring receive identical genes and are clones of the parent.
Why this scores
Three marks: one parent / no gamete fusion; produced by mitosis; exact copy of DNA / identical genes.
Explain the advantages of asexual reproduction for a plant living in a favourable, unchanging environment. (4 marks)
Model answer
Asexual reproduction needs only one parent, so the plant does not need to find a mate or rely on pollination, which makes reproduction fast and reliable, and many offspring can be produced quickly. Because the offspring are genetically identical to the parent, and the parent is well suited to the favourable environment, all the offspring will be equally well suited to it. So in a stable, favourable environment the plant can rapidly produce many successful, well-adapted offspring.
Why this scores
Four marks: only one parent / no mate or pollination needed; fast and reliable; offspring identical; all suited to the (favourable) environment.
Explain why asexual reproduction can be a serious disadvantage if a new disease appears in the environment. (5 marks)
Model answer
All the offspring produced by asexual reproduction are genetically identical to the parent and to each other, so there is no genetic variation in the population. If a new disease appears, and the parent is not resistant to it, then none of the offspring will be resistant either, because they all have the same genes. As a result, the disease could affect all the individuals in the population. With no variation, there are no resistant individuals that could survive and reproduce, so the whole population could be wiped out. This is why a lack of variation makes asexually reproducing populations vulnerable to changes such as new diseases.
Why this scores
Five marks: offspring genetically identical / no variation; if parent not resistant, none are; disease can affect all; no resistant individuals to survive; whole population at risk.
Compare asexual and sexual reproduction, and explain in which conditions each is an advantage. (6 marks)
Model answer
Asexual reproduction involves one parent and no fusion of gametes, producing genetically identical offspring (clones); sexual reproduction involves the fusion of two gametes (usually from two parents), producing offspring that show genetic variation. Asexual reproduction is an advantage in a stable, favourable environment: it is fast, needs no mate, and because the offspring are identical to a well-suited parent, they too are well suited, so many successful offspring are produced quickly. Sexual reproduction is an advantage when the environment changes or is varied: because the offspring vary genetically, some may by chance be better suited to the new conditions, or resistant to a new disease, and these can survive and reproduce, so the population can adapt and survive. So asexual reproduction suits stable conditions, while sexual reproduction, through variation, helps populations cope with change.
Why this scores
Up to 6 marks: definitions/contrast (one parent vs gamete fusion; identical vs varied offspring); asexual advantage in stable conditions (fast, no mate, all suited); sexual advantage when conditions change (variation → some better suited/disease-resistant → population adapts).
Definitions to memorise and the exact keywords mark schemes credit for asexual reproduction answers — sharpened from recent examiner reports for the 2026 0610 sitting.
A process resulting in genetically identical offspring from one parent, without the fusion of gametes.
A genetically identical copy of an organism, produced by asexual reproduction.
Asexual reproduction in bacteria: the DNA is copied, then the cell divides into two identical daughter cells.
The traps other students keep falling into on asexual reproduction questions — taken from recent Cambridge IGCSE 0610 examiner reports and mark schemes — and how to avoid them.
Why it happens
All reproduction sounds 'sexual'.
How to avoid it
Asexual reproduction needs only ONE parent — no mate and no gametes. Sexual reproduction needs two gametes.
Why it happens
Offspring are 'identical'.
How to avoid it
Rare random mutations can occur, but effectively the offspring are clones with no meaningful genetic variation.
The things students keep getting wrong in this sub-topic, answered.