Meiosis And Recombination Flashcards
0
Q
What is the goal of meiosis?
A
- make four haploid gamete that are not identical to the original
- when they combine you get a diploid
1
Q
What is the goal of mitosis
A
-end up with two identical cells to the original that are both diploid
2
Q
Interphase of meiosis
A
- Where cells spend a majority of their time
- where all the genetic material is replicated
3
Q
Prophase I
A
- centrioles migrate to their poles
- homologous chromosomes pair up and form a tetrad
- crossing over
- longest step in meiosis
- nuclear envelope is disappearing
4
Q
Metaphase I
A
-tetrads line up across metaphase plate
5
Q
Anaphase I
A
- pulling apart homologous sets of chromosomes
- pulling apart tetrads
6
Q
Telophase I and cytokenesis
A
Makes two haploid cells
7
Q
Prophase II
A
- nuclear envelope disappears
- centromeres migrate to opposite poles
8
Q
Metaphase II
A
Sister chromatids line up on metaphase plate
9
Q
Anaphase II
A
Sister chromatids are pulled apart
10
Q
Telephase II and cytokenesis
A
End up with four haploid gametes
11
Q
What do we pull apart in meisis I? II?
A
I:Tetrads
II: sister chromatids
12
Q
Problems in meiosis
A
- Nondisjunction
2. Translocation
13
Q
Nondisjunction
A
- failure of tetrads to separate during meiosis i or sister chromatids in meiosis
- can lead to:
1. Down syndrome (trisomy 21)
2. Turner syndrome (x)
3. Kleinfelter syndrome (xxy)
14
Q
Nondisjuction in meiosis I
A
Creates two trisomies and two monosomies
