Cell division Flashcards
Meiosis
What happens in the interface
DNA in chromosomes copies itself ready for mitosis
What happens in prophase
The copies condense becoming more visible
the membrane around the nucleus disappears
What happens in the metaphase
Chromosomes and their copies line up in the middle of the cell
What happens in the anaphase
Chromosomes get pulled to other sides of the cell
What happens in the telophase
New membranes form around the chromosomes at each end of the cell
the cytoplasm starts to divide
What is cytokinesis
The cytoplasm divides to form two identical cells
How many cells do you get at the end of mitosis?
2 identical daploid cells
How many cells do you get at the end of meiosis?
4 haploid cells nono-identical
What is Spermatogenesis?
Spermatogenesis is the process of stem cells turning into specialised sperm cells
What is Oogenesis?
Similar to Spermatogenesis but it is when the stem cells become specialised into ovum.
What happens in Spermatocytogenesis?
(mitosis)
This is where the stem cells copy themselves and divide into more cells. Some differentiation occurs that the nuclei is spherical.
What happens after Spermatocytogenesis in Spermatogenesis?
Meiosis
This is the longest stage, the stem cells go from diploid to haploid as they unpair the chromosomes. This produces 4 daughter cells
What happens in
Spermiogenesis in Spermatogenesis?
No further mitosis or meiosis occurs. The stem cells become specialized by developing the acrosome, the flagellum and cytoplasm.
What happens in the pre-antral stage?
Meiosis occurs and the cell will grow larger in size at this stage. The follicular cells grow and form stratified cuboidal epithelium which will secrete glycoproteins which will later become the zona pellucida. This is called granulosa cells.
What happens in the antral stage
FSH, LH and oestrogen cause secondary follicles to develop. Fluid fills the spaces between the granulosa cells and these will combine together to form the antrum (central fluid filled space)
