CIE iGCSE Biology-16.1 Asexual reproduction- Study Notes- New Syllabus
CIE iGCSE Biology-16.1 Asexual reproduction- Study Notes – New syllabus
CIE iGCSE Biology-16.1 Asexual reproduction- Study Notes -CIE iGCSE Biology – per latest Syllabus.
Key Concepts:
Core
- Describe asexual reproduction as a process resulting in the production of genetically identical offspring from one parent
- Identify examples of asexual reproduction in diagrams, images and information provided
Supplement
- Discuss the advantages and disadvantages of asexual reproduction:
(a) to a population of a species in the wild
(b) to crop production
Asexual Reproduction
✅ Definition:
Asexual reproduction is a process in which one parent produces genetically identical offspring without the involvement of gametes (no fertilisation).
🔍 Key Features:
| Feature | Description |
|---|---|
| Number of parents | Only one parent is involved |
| Offspring | Are clones – genetically identical to the parent |
| No gametes or fertilisation | Reproduction occurs without sperm or egg cells |
| Mitosis | Cell division by mitosis enables the exact copying of genetic material |
🧫 Examples in Nature:
| Organism/Method | Description |
|---|---|
| Bacteria | Divide by binary fission |
| Fungi | E.g. Yeast reproduce by budding |
| Plants | E.g. Strawberries using runners, potatoes using tubers |
| Some animals | E.g. Hydra reproducing by budding |
✅ Advantages:
- Fast reproduction (no need to find a mate)
- Energy-efficient
- Useful in stable environments
❌ Disadvantages:
- No genetic variation
- All offspring are vulnerable to the same diseases and environmental changes
🗒️Note:
Asexual reproduction = 1 parent, no gametes
Offspring = exact clones (no variation)
Mitosis is the key process
Asexual reproduction = 1 parent, no gametes
Offspring = exact clones (no variation)
Mitosis is the key process
Identifying Asexual Reproduction
Asexual reproduction involves only one parent and produces genetically identical offspring (clones) without gametes or fertilization.
🧫 Common Examples to Identify:
| Organism/Type | Asexual Method | What to Look for in Diagrams or Images |
|---|---|---|
| Bacteria | Binary fission | One cell splitting into two identical ones |
| Yeast (Fungi) | Budding | A small bud growing off the parent cell |
| Hydra | Budding | A mini Hydra growing from the body of the parent |
| Strawberry plants | Runners (stolons) | Horizontal stems with new baby plants at nodes |
| Potatoes | Tubers | Enlarged underground structures sprouting new plants |
| Onions/Garlic | Bulbs | Bulb sections producing identical shoots |
| Bryophyllum (Plant) | Leaf buds | Baby plantlets growing on leaf edges |
Asexual Reproduction – Advantages and Disadvantages
(a) In the Wild (Natural Ecosystems)
| Advantages | Disadvantages |
|---|---|
| Only one parent is needed – no need to find a mate | No genetic variation – all offspring are clones |
| Can reproduce quickly and efficiently | All individuals equally vulnerable to disease or environmental change |
| Fast colonisation of suitable environments | No adaptation to new or changing conditions over time |
| Successful traits are passed on unchanged | A single harmful mutation affects all offspring |
🌾 (b) In Crop Production (Agriculture)
| Advantages | Disadvantages |
|---|---|
| Farmers can grow identical plants with desired traits (e.g. taste, size) | Crops are genetically identical – no resistance to new diseases |
| Ensures uniformity in quality and appearance | Over-reliance on one variety → risk of entire crop failure |
| Faster reproduction of high-yield varieties | Cannot develop new traits through natural variation |
| Useful for reproducing seedless fruits (e.g. bananas) | Reduces biodiversity in farming systems |