Types of Reproduction

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  • Topic: Asexual reproduction, Bacteria, Spore
  • Pages : 2 (512 words )
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  • Published : January 23, 2013
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Gametes are sex cells.
Fertilisation is when half the genetic material comes from male gamete and half come from female gamete and they fuse together to form a zygote. Zygote is a fertilized egg.
Embryo is a divided zygote.

Binary Fission in Bacteria
Bacteria are microscopic organisms made up of one cell and they do not have a nucleus but a loop of DNA. When bacteria, reproduce asexually the DNA loop is copied so that there is some for each new cell. The bacterial cell deivides into two by making a new cell wall. This type of asexual reproduction is called binary fission.

Spore Production in Fungi
Pin mould is a fungus which grows on bread and reproduces asexually by making spores. They are small and light like spects of dust, and float through the air. When spore lands on a damp surface, it splits open and thread grows out. The hypha (thread) grows over surface of bread forming a dense network of threads called a mycelium. Eventually, short hyphae grow upwards and produce spore casesor sporangia at their tips. Inside each sporangium hundreds of new spores are formed asexually by division of nuclei. Each nucleus gains a small qty of cytoplasm and a protective spore case. When ready, it breaks open and spores are dispersed.

Tuber formation in potatoes
* Potatoes reproduce asexually by stem tubers.
* They are swollen underground stems that grow from parent plant * Sucrose is transported in the phloem from the leaves into these underground stems that swell as they convert sucrose > starch. * Parent plant dies at end of growing season but tubers are left to survive over the winter. * Farmers dig em up and sell em.

* Some are kept as seed potatoes to plant the next year and all the tubers are genetically identical. * When regrowing, new shoots/roots emerge from growing point of potato, know as eyes.

| Asexual| Sexual|
Advantages | * Fast * Reproduces rapidly to spread and colonise areas where the parent...
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