Genetic Code & Cell Function
- Created by: beth-marie2511
- Created on: 19-06-16 13:10
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- Genetic Code & Cell Function
- Meiosis 2
- Prophase 2
- New spindles begin to form at right angles to the spindles in prophase 1
- Metaphase 2
- Chromosomes arrange themselves on the equator of the spindle fibres
- Each chromosome is attached to the spindle via the centromere
- Anaphase 2
- Centromeres divide
- Spindle fibres contract
- Chromatids are pulled to the opposite poles
- Telophase
- Chromatids uncoil and lengthen
- Spindles disappear
- Nuclear envelope reforms
- 4 daughter haploid cells
- Prophase 2
- Significance of Meiosis
- Meiosis halves the chromosome numbers = haploid chromosomes
- Genetic variation in the gametes and therefore in the zygote
- Two main ways genetic variation occurs
- Crossing over during prophase 1
- Independent assortment during metaphase 1
- Random fusion of gametes
- Produces more variation in the offspring
- Differences between meiosis 1 & meiosis 2
- Crossing over occurs in Prophase 1 but not Prophase 2
- Homologous bivalents align at the equator in Metaphase 1
- Chromosomes align at the equator in Metaphase 2
- Independent assortment occurs in Metaphase 1
- It does not occur in Metaphase 2
- 2 daughter cells are formed in meiosis 1
- 4 daughter cells are produced in meiosis 2
- All daughter cells are haploid
- Meiosis 2
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