Flashcards
Biology 2.1.6 Meiosis
Cards in this deck (18)
- 1What happens during interphase of meiosis?The DNA replicates so each chromosome contains two chromatids
- 2What happens during early prophase of meiosis?The nuclear envelope breaks down and centrioles move to poles and form spindle fibres made of microtubles
- 3What happens during late prophase in meiosis?Homologous pairs from bilavents (where one paternal and one maternal chromosome bind throuhgh crossing over)Crossing over occurs
- 4What is crossing over?Chromosomes cross over at a point called the chaismata and DNA is swapped
- 5What is a bilavent?A pair of homologous chromosomes held together by at least one DNA crossover
- 6What happens during metaphase 1 of meiosis?The bilavents randomly line up at the equator and spindle fibres attach to the centromeres
- 7What happens during anaphase 1 of meiosis?The homologous pair of chromosomes of each bilavent are pulled away from eachother to the poles by spindle fibres
The centromoeres don't divide, each chromosome still has two chromatids
- 8What happens during telophase 1 of meiosis?In animal cells, the nuclear envelope will reform and cytokinesis may start
- 9What happens during prophase 2 of meiosis?The centrioles replicate, and nuclear envelope disintergrates
The chromosomes (each have two chromatids) recondense
- 10What happens during metaphase 2 of meiosis?Chromosomes randomly line up at the equator and centromeres attach to the spindle fibres
- 11What happens during anaphase 2 of meiosis?The centromeres divide and the chromatids are pulled to opposite poles
- 12What happens during telophase 2 of meiosis?The chromatids (now chromosmes) have reached the poles and the nuclear envelope reforms, forming four seperate nuclei
- 13How many daughter cells are produced through meiosis? Are these daughter cells haploid or diploid?Four daughter cells are produced
Haploid - 14How does crossing over cause genetic variation?When chromosomes cross over, they have the same genes, but may have different alleles, causing variation
- 15When during meiosis does crossing over occur?Prophase 1
- 16How does independent assortment of chromosomes cause genetic variation?Each bilavent behaves independently so it could face either way so any combination of maternal or paternal chromosomes could end up in each gamete produced
- 17When during meiosis does independent assortment take place?Metaphase 1
- 18What other causes of variation are there?Random ferilisation (any sperm can fertilise egg)
Independent assortment of chromatids
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- User has deleted their subject information Flashcards on Biology 2.1.6 Meiosis, created by Deleted user on 07/06/2019.
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- Deleted user · Jun 2019
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- Jun 7, 2019
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- Created by Sam Gunnell · Feb 11, 2019
- Copied by Sam Gunnell · Jun 7, 2019
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