Meiosis Flashcards
What is the first meiosis division referred to as?
Reductional
What is the second meiosis division referred to as?
Equational
What is crossing over?
Process by which the shuffling of genetic material occurs
When does crossing over occur?
Prophase 1
How does crossing over occur?
Homologous chromosome attach at the to chiasmata to form a tetrad
What splits in anaphase 1?
Homologous chromosomes
What splits at anaphase 2?
Sister chromatids
What are the differences between mitosis and meiosis?
- no of divisions
- no of cells produced
- no of chromosomes in daughter cells
- pairing of homologous chromosomes
- crossing over
- splitting of genetic material
- function
- genetic differences in daughter/parent cells
What are the two types of spermatogonium?
Type A: proliferate by mitosis
Type B: undergo meiosis
What is the process of spermatogenesis?
- spermatogonium become primary spermatocytes
- primary spermatocytes undergo the first meiotic division to become secondary spermatocytes
- secondary spermatocyte undergo the second meiotic division to form spermatids
- spermatids undergo spermiogeneis to become mature spermatozoa
What are the three stages of oogenesis and spermatogenesis?
Mitotic proliferation
Meiotic division
Cell remodelling
How long does spermatogenesis take?
Around 74 days
When does a primary oocyte complete its first meiotic division?
A day before ovulation
What occurs in spermiogenesis?
- Golgi forms acrosomal vesicle and then acrosome which covers the head of the sperm
- nucleus condenses
- distal centriole migrates out to membrane and forms the flagellum, mitochondria migrate to proximal part of flagellum
- cytoplasm ejected as a residual body