Meiosis Flashcards
(19 cards)
Where does meiosis occur?
Reproductive cells
What type of reproduction does meiosis produce?
Sexual reproduction (different cells)
What type of cells does meiosis produce?
Haploid cells called gametes
How does meiosis produce genetic diversity?
-Independent assortment of chromosomes
-Crossing over of chromosomes
Why is genetic diversity important?
-Faciliates evolution
-Healthy population
-Large gene pool
What are the stages of meiosis 1?
-Prophase 1
-Metaphase 1
-Anaphase 1
-Telophase
What are the stages of meiosis 2?
-Prophase 2
-Metaphase 2
-Anaphase 2
-Telophase
What is the first step before meiosis?
The duplication of chromosomes
When does the duplication of chromosomes for meiosis occur?
Interphase (G0, G1, S phase)
What occurs during prophase 1?
-Development of spindle
-Breakdown of membrane
-Centrosomes move towards poles
-Chromosome pairs form
What occurs during metaphase 1?
-Random orientation of chromosomes align along axis
-Crossing over can also occur
What occurs during anaphase 1?
-Kinetochore spindle fibres contract
-Homolgous pairs pulled from each other towards poles
-Chromosomes move to separate poles
-Centromeres don’t separate
What occurs during telophase 1?
-Cleavage furrow + cytokinesis
-Nuclear envelope does not reform
-Daughter cells have one set of chromosomes (haploid)
What occurs during meiosis 2?
-Separates the chromatids producing 2 daughter cells with haploid chromosomes
What occurs during prophase 2?
-New set of spindle fibres form
-Chromosomes move to equator
What occurs during metaphase 2?
Chromosomes in the 2 cells align along the metaphase plate
What occurs during anaphase 2?
-Centromeres split
-Kinetochore splits
-Spindle fibres shorten and draw chromosomes to each pole
What occurs during telophase 2?
-Cleavage furrow
-Cytokinesis
-Nuclear envelope forms
-Chromosomes fade
What are the products of meiosis 2?
4 haploid daughter cells
