วันจันทร์ที่ 8 สิงหาคม พ.ศ. 2554
3.1 Sexual and Asexual Reproduction
Sexual Reproduction:
1. Organisms that show reproduction: Sexes - male / female
2. Sexually reproducing organisms produce cells called "Gametes"= formed in the male of the sperm cell (in plants = pollen grain) and in the female of the egg cell (in plants = ovule)
3. Type of cell division that produces gametes = Meiosis - one of the effects: half the total adult number of chromosomes in the gamete cell.
In humans, total number of chromosomes: 46 per cell
In gametes, total number of chromosomes: 23 per gamete cell
Going from 46-->23 is the process of cell division called Meisosis
4. Find the process of Fertilisation - in which gamete cells (the sperm cell and the egg cell) fuse together
5. Population: variation - broad. Many differences in the individuals of a sexually reproducing population
Asexual Reproduction:
1. No such sexes exist in asexual reproduction
2. No gametes
3. No meiosis, there is mitosis in eukaryotic cells and binary fission in prokaryotic bacterial cells
in this process, the number of chromosomes is maintained constantly, a cell with 20 chromosomes will divide to produce two cells with 20 chromosomes each. The two cells are identical
4. No fertilisation
5. Small amount of variation due to mutation - mostly identical - clone
How do plants reproduce asexually?
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