Meiosis Flashcards
Mutagens
Factors that cause mutations
Carcinogens
Factors that cause mutations that lead to cancer
Haploid cell - how many chromosomes total
23 total - n
Haploid cell
+ example
Single set of chromosomes
(ex. gamete)
Diploid cell
Two homologous chromosomes
Mitosis
Produces cells for growth & repair
Doploid cell - how many chromosomes total
46 total - 2n
Meiosis
Produces gametes For reproduction
Why is meiosis crutial
it reduces the chromosome number by half ensuring that when two gametes combine the offspring will have the correct number of chromosomes
How many times does interphase happen
once
Interphase:
- G1
- S-phase
- G2
- G1: cell growth → produces proteins & organelles
- S-phase: chromosome replication process
- G2: cell growth & preperation for division
what happens in Meiosis 1
seperation of homologous pairs
what happens in Meiosis 2
Seperation of sister chromatids no s-phase betwen them
Prophase 1
Chiasmata
+ whats formed
Chiasmata → specific places where homologous chromosomes connect and form tetrads
crossing over (+when)
P1: non sister chromatids
of homolegous pairs exchange DNA
Metaphase (1)
(3)
- Homologous pairs of chremosomes line up on the metaphase plate
- A spinale fiber from one end pale attaches to one hair le a spindle fiber from the sther end pole to the other
- The homologous pairs are then seperated into different nuclei
Anaphase (1)
The Homologous pairs seperate & then move the opposite ends of the sell
A1
Each chromosome has how many sister chromatids
Each chromosome still has two sister chromatids
Telophase and cytokinesis (1)
The chromosomes consisting of two sister chromatids seperate into two daughter cells, each with one chromosome of two sisters
Meiosis (2) - what doesn’t it have?
Doesn’t have an interphase
What happens in meiosis 2
the sister chromatids are seperated
what is there by the end of meiosis 2
by the end of meiosis 2, there are 4 daughter haploid cells (NO sister chromatids)
Spermatogenisis
gamete → sperm