CH6 meiosis Flashcards
1
Q
What is a gamete
A
A sex cell
2
Q
What is a zygote
A
A fertilised egg
3
Q
What does diploid mean
A
The standard number of chromosomes of an organism
4
Q
What is a haploid cell
A
A cell with half the number of chromosomes of a parent
5
Q
What is a homologous chromosomes
A
- matching pair of chromosomes
- each chromosome in a homologous pair has the same gene in the same loci
6
Q
What is an allele
A
A different version of the same gene
7
Q
What happens during meiosis 1
A
Pairs of homologous chromosomes are seperated into two cells
8
Q
What happens during meiosis 2
A
Pairs of chromatids are seperated
9
Q
What happens in prophase 1
A
- chromosomes condense
- nuclear envelope disintegrates and nucleolus disappears
- spindle formation begins
- homologous chromosomes pair up forming bivalents, when chromosomes are brought together the chromatids entangle (crossing over)
10
Q
What happens in metaphase 1
A
- homologous chromosomes assemble along metaphase plate
- orientation of each homologous pair is random which results in independent assortment
11
Q
What happens in anaphase 1
A
- homologous pairs are pulled to opposite poles
- entangled chromatids break off and rejoin at point called chiasmata
- recombinant chromatids form
12
Q
What happens in telophase 1
A
- chromosomes assemble at each pole
- nuclear membrane reforms
- chromosomes uncoil
13
Q
What happens in prophase 2
A
- chromosomes condense and become visible
- nuclear envelope breaks down
- spindle formation begins
14
Q
What happens in metaphase 2
A
- individual chromosomes assemble on metaphase plate
- more independent assortment occurs
15
Q
What happens in anaphase 2
A
- centromeres divide
- chromatids pulled to opposite poles
16
Q
What happens in telophase 2
A
- chromatids assemble at poles
- chromosomes uncoil and form chromatin
- nuclear envelope reforms and nucleolus becomes visible
