Triple Science Only - Advantages And Disadvantages Of Sexual And Asexual Reproduction
Laura Armstrong & Joe Wolfensohn
Teachers
Recall Questions
This topic requires prior knowledge of sexual and asexual reproduction.
How many parents are required for asexual reproduction?
One parent only.
What is the main advantage of sexual reproduction?
It produces genetic variation in the offspring.
Which type of reproduction requires fertilisation to take place?
Sexual reproduction.
Topic Explainer Video
Check out this @JoeDoesBiology video that explains advantages and disadvantages of sexual and asexual reproduction, then read the study notes. Once you’ve gone through them, don’t forget to try the practice questions!
Advantages And Disadvantages Of Sexual And Asexual Reproduction
What is Reproduction?
- Reproduction is the process by which organisms produce offspring.
- It can be sexual or asexual, each with its own advantages.
Sexual Reproduction
- Involves the fusion of gametes (e.g., sperm and egg in animals, pollen and ovules in plants).
- Gametes are produced by meiosis.
- Leads to offspring with genetic variation.
Advantages:
- Gives rise to genetic variation in offspring.
- If the environment changes, variation gives a survival advantage. Those best adapted can survive and reproduce (natural selection).
- Sexual reproduction in plants will produce seeds- these can be dispersed by the wind and animals. Plants that use sexual reproduction can therefore colonise (or grow) in new areas.
- Selective breeding by humans can speed up natural selection to produce desirable traits (e.g. in crops or animals).
Disadvantages:
- Two parents are needed (animals must find a mate, plants rely on pollination). This takes time and requires more energy. As a result sexual reproduction is more time consuming and energy demanding.
Asexual Reproduction
- No gametes involved and no fertilisation.
- Only one parent is required
- Offspring are genetically identical to the parent (clones).
Advantages:
- Only one parent needed so it is a faster process and uses less energy. In plants, they do not have to wait for flowers and seeds to form. In animals, they do not need to find a mate.
- Many genetically identical offspring can be produced quickly when conditions are favourable.
- This means all offspring will have the same advantageous traits as the parent. For example, if the parent plant has large, tasty fruits, the offspring plant will too.
Disadvantages:
- No genetic variation - all offspring susceptible to the same diseases.
- Less chance of survival if environment changes.
Examples of Organisms that Use Both Types of Reproduction:
|
Organism |
Asexual Reproduction |
Sexual Reproduction |
|---|---|---|
|
Malarial parasite |
Asexually in the human host. |
Sexually in the mosquito. |
|
Fungi |
By spores. |
Also sexually to give variation. |
|
Strawberry plant |
By runners. |
Produces seeds sexually via flowers. |
|
Daffodils |
By bulb division. |
Produces seeds sexually via flowers. |
Strawberry plant reproducing asexually using runners and sexually using flowers.
Key Terms & Definitions
|
Term |
Definition |
|---|---|
|
Asexual reproduction |
Reproduction involving one parent; offspring are genetically identical (clones). |
|
Sexual reproduction |
Involves the fusion of male and female gametes, producing genetically varied offspring. |
|
Variation |
Differences in the genetic makeup of individuals within a species. |
|
Selective breeding |
Human-controlled reproduction to enhance desirable traits in plants and animals. |
|
Natural selection |
Survival of the fittest – organisms with favourable traits are more likely to survive and reproduce. |
No answer provided.
Exam Tip:
You are expected to be able to explain the advantages and disadvantages of asexual and sexual reproduction for any organism if given appropriate information. Make sure you read any information provided carefully.
No answer provided.
Practice Questions
Explain the advantages of both sexual and asexual reproduction for organisms that can reproduce in both ways. Use examples in your answer. (6 marks)
Model Answer:
- Asexual reproduction is faster and does not require the production of flowers or the development of seeds, for example in daffodils, which saves time and energy.
- It allows organisms like strawberry plants to quickly produce many offspring by runners when conditions are favourable.
- It allows organisms to produce genetically identical offspring with advantageous traits, such as large, red strawberries.
- Malarial parasites reproduce asexually in humans, allowing rapid multiplication inside the host.
- Sexual reproduction, used by these organisms in certain situations, introduces genetic variation.
- Variation is useful if the environment changes, helping survival through natural selection.
- For example, fungi reproduce sexually to introduce genetic variation when adapting to a new environment or fighting disease.
More Practice
Try to answer the practice question from the TikTok video on your own, then watch the video to see how well you did!