Reproduction and Variation. By the end of the lesson, you should be able to: Describe asexual...
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Transcript of Reproduction and Variation. By the end of the lesson, you should be able to: Describe asexual...
![Page 2: Reproduction and Variation. By the end of the lesson, you should be able to: Describe asexual reproduction. Describe sexual reproduction. Explain.](https://reader035.fdocuments.us/reader035/viewer/2022062804/5697bf8e1a28abf838c8d096/html5/thumbnails/2.jpg)
LEARNING OUTCOMES
By the end of the lesson, you should be able to:
Describe asexual reproduction.Describe sexual reproduction.Explain why sexual reproduction results in
variation, but asexual reproduction does not produce variation.
Describe differences in characteristics due to genetic or environmental causes or a combination of both.
![Page 3: Reproduction and Variation. By the end of the lesson, you should be able to: Describe asexual reproduction. Describe sexual reproduction. Explain.](https://reader035.fdocuments.us/reader035/viewer/2022062804/5697bf8e1a28abf838c8d096/html5/thumbnails/3.jpg)
TYPES OF REPRODUCTION
• There are two very different ways of reproducing:– Asexual reproduction– Sexual reproduction
![Page 4: Reproduction and Variation. By the end of the lesson, you should be able to: Describe asexual reproduction. Describe sexual reproduction. Explain.](https://reader035.fdocuments.us/reader035/viewer/2022062804/5697bf8e1a28abf838c8d096/html5/thumbnails/4.jpg)
ASEXUAL REPRODUCTION IN PLANTS
BULBS
Onions Daffodils
Look at the examples of asexual reproduction.
Can you give a definition of the process?
![Page 5: Reproduction and Variation. By the end of the lesson, you should be able to: Describe asexual reproduction. Describe sexual reproduction. Explain.](https://reader035.fdocuments.us/reader035/viewer/2022062804/5697bf8e1a28abf838c8d096/html5/thumbnails/5.jpg)
TUBERS
Potatoes
![Page 6: Reproduction and Variation. By the end of the lesson, you should be able to: Describe asexual reproduction. Describe sexual reproduction. Explain.](https://reader035.fdocuments.us/reader035/viewer/2022062804/5697bf8e1a28abf838c8d096/html5/thumbnails/6.jpg)
RHIZOMES
Iris
![Page 7: Reproduction and Variation. By the end of the lesson, you should be able to: Describe asexual reproduction. Describe sexual reproduction. Explain.](https://reader035.fdocuments.us/reader035/viewer/2022062804/5697bf8e1a28abf838c8d096/html5/thumbnails/7.jpg)
RUNNERS
Strawberry Spider plant
![Page 8: Reproduction and Variation. By the end of the lesson, you should be able to: Describe asexual reproduction. Describe sexual reproduction. Explain.](https://reader035.fdocuments.us/reader035/viewer/2022062804/5697bf8e1a28abf838c8d096/html5/thumbnails/8.jpg)
ASEXUAL REPRODUCTION
• No fusion of gametes.• Only one individual is needed as the
parent. • There is no mixing of genetic
information and so no genetic variation in the offspring.
• These genetically identical individuals are known as clones.
![Page 9: Reproduction and Variation. By the end of the lesson, you should be able to: Describe asexual reproduction. Describe sexual reproduction. Explain.](https://reader035.fdocuments.us/reader035/viewer/2022062804/5697bf8e1a28abf838c8d096/html5/thumbnails/9.jpg)
Advantages of Asexual Reproduction
Advantages Disadvantages
Asexual ReproductionSexual Reproduction
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ASEXUAL REPRODUCTION• Only involves one parent.• Offspring are completely identical to
the parent – clones!• No gametes (sex cells) are needed.• Very safe and easy – no need to find a
partner!• Common in small/simple animals,
plants and bacteria.• Also happens in our body all the time –
to replace worn out or dead cells.• It also happens in some bigger plants.
![Page 11: Reproduction and Variation. By the end of the lesson, you should be able to: Describe asexual reproduction. Describe sexual reproduction. Explain.](https://reader035.fdocuments.us/reader035/viewer/2022062804/5697bf8e1a28abf838c8d096/html5/thumbnails/11.jpg)
SEXUAL REPRODUCTION
• Involves the joining (fusion) of the male and female gametes (sperm and egg).
• The mixture of the genetic information from two parents leads to variety in the offspring.
![Page 12: Reproduction and Variation. By the end of the lesson, you should be able to: Describe asexual reproduction. Describe sexual reproduction. Explain.](https://reader035.fdocuments.us/reader035/viewer/2022062804/5697bf8e1a28abf838c8d096/html5/thumbnails/12.jpg)
VARIATION
• Genetic Variation• Environmental Variation
Which of the following characteristics are the result of genetic variation, environmental
variation or both?
Gender Weight Hair length
Height Tattoo Eye colour
Hair colour Tongue-rolling Shoe size
Why is variation in a population important?
![Page 13: Reproduction and Variation. By the end of the lesson, you should be able to: Describe asexual reproduction. Describe sexual reproduction. Explain.](https://reader035.fdocuments.us/reader035/viewer/2022062804/5697bf8e1a28abf838c8d096/html5/thumbnails/13.jpg)
SEXUAL REPRODUCTION IN PLANTS
• In plants, the eggs are found in ovules (in the ovary of flowers), and the sperm cells are found in pollen.
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Pollen grains
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FRUIT OR VEGETABLE?
• When the flower has been pollinated, the sperms meet the eggs, and seeds form (the offspring!)
• The ovary turns into the fruit – with seeds inside ready for dispersal.
Which of the following are fruits? Vegetables?
Are they produced by sexual or asexual reproduction?
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VEGETABLE!ASEXUAL
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FRUIT!SEXUAL
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FRUIT!SEXUAL
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VEGETABLE!ASEXUAL
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FRUIT!SEXUAL
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FRUIT!SEXUAL
![Page 22: Reproduction and Variation. By the end of the lesson, you should be able to: Describe asexual reproduction. Describe sexual reproduction. Explain.](https://reader035.fdocuments.us/reader035/viewer/2022062804/5697bf8e1a28abf838c8d096/html5/thumbnails/22.jpg)
VEGETABLE!ASEXUAL
![Page 23: Reproduction and Variation. By the end of the lesson, you should be able to: Describe asexual reproduction. Describe sexual reproduction. Explain.](https://reader035.fdocuments.us/reader035/viewer/2022062804/5697bf8e1a28abf838c8d096/html5/thumbnails/23.jpg)
SUMMARY
• Fruits always come from a ______.
• Fruits are made through ______ reproduction!
flower
sexual