4.1 |
Sexual and Asexual Reproduction |
Definition |
Reproduction is the process of producing new individuals from living organisms. |
Reproduction |
Sexual |
Asexual |
Involves reproductive cells |
Does not involve reproductive cells |
Occurs in:
- humans
- higher animal (mammal, bird, fish, reptile and amphibian)
- flowering plant
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Occurs in:
- plants (onion, ginger, potato)
- simple organism (Amoeba, Hydra, Paramecium)
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Parent |
Male |
Female |
Carries male reproductive cell |
Carries female reproductive cell |
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Differences between internal and external fertilisation |
Internal |
External |
The nucleus of the male gamete fuses with the nucleus of the female gamete inside the body of female parent |
Nucleus of male gamete fuses with nucleus of female gamete outside the body of female parent |
Male parent releases sperm into the body of female parent |
Male parent releases sperm and female parent releases ovum. Occurs in the water. |
Male gamete from the male reproductive organ will be released into the female organ which has the female gamete and fuses to form a zygote |
Male gamete usually swims towards the ovum and fuses with itt. |
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Asexual Reproduction
Binary fusion |
Binary fission is the division of a single parent cell into two daughter cells. |
Example: Amoeba, Paramecium and bacteria |
Budding |
- Budding is the process of forming a bud on the organism's body.
- A bud starts off as a sweeling. Then, it develops and breaks off as a new young
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Example: Hydra and yeast |
Regeneration |
Occurs from the ability of the fragments of some organisms to grow and develop into completely new indiciduals. |
Examples: Flatworm, starfish and Planaria |
Spore formation |
- Spore formation is the process of producing spores in the sporangium.
- After the sporangium breaks, the tiny and light spores getscattered by the wind.
- When they land on a moist place, they grow into new plants.
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Vegetative reproduction |
- Vegetative reproduction is a method of producing newplants from avegetative part of a plant except the flower.
- Example of vegetative parts are the roots, underground stems, runners, bulbs and leaves.
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Examples: Carrot, strawberry, ginger, yam and potatoes |
There are three types of vegetative reproduction:
Root - Roots of parent plant will grow into new plant |
Example: Carro, sweet potato |
Stem - Stem of parent plant will row into new plant |
Example: Potato, onion, grass |
Leaf - Leaves of parent plant will grow into new plants |
Example: Bryophyllum, Begonia |
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The importance of reproduction:
- Increase the number of organisms of a species
- Transfers the genetic information to the new generation