What are the 2 key process of sexual reproduction?
1.formation of haploid cells 2.2 sex cells joining to form fertilized cell (zygote)
New cards
2
What are gametes?
Sex cells that contain genetic information from parents
New cards
3
What is meiosis?
Process through which haploid gametes are formed
New cards
4
What is the difference between mitosis and meiosis?
in mitosis, # of chromosomes stays the same, but in meiosis # is cut in half
New cards
5
What does the combination of 2 gametes result in?
complete set of chromosomes
New cards
6
What does the combination of 2 gametes result in?
Complete set of chromosomes
New cards
7
What forms homologous chromosomes?
Complete set of DNA from each parent
New cards
8
How many haploid gametes does meiosis produce
4
New cards
9
What is gametogenesis?
formation of sex cells: 2 types in humans
New cards
10
What happens in prophase 1?
Homologous chromosomes come together
New cards
11
How many sister chromatids are in each chromosome?
2 sister chromatids (one chromosome from each parent)
New cards
12
How many chromatids form a tetrad?
4
New cards
13
Where does the crossing over between homologous chromosomes occur?
Prophase 1
New cards
14
Where do intertwined chromosomes break off and reattach at?
the chiasmata
New cards
15
What happens in metaphase 1?
tetrads migrate towards center off cell
New cards
16
what is the difference between metaphase 1 in meiosis and mitosis?
in mitosis there are only sister chromatids lining up in the cetre, whereas in meiosis, the tetrads are lining up to the center of the cell
New cards
17
What happens in anaphase 1?
homologous chromosomes move to opposite poles of the cell as the spindle fibers shorten
New cards
18
Will both chromosomes from each homologous pair be in each new daughter cell?
no, only one to make the new daughter cell genetically unique
New cards
19
What is the difference between anaphase 1in meiosis and anaphase in mitosis?
in mitosis, the sister chromatids are being pulled apart, but in anaphase we are splitting up the homologous chromosomes
New cards
20
What happens in telophase 1?
nuclear membrane reforms, spindle fibers dissolve cells begins to divide
New cards
21
How many duplicated copies of chromosomes are made at this point
1
New cards
22
During telophase 1, are cells haploid or diploid? why or why not?
They are haploid, because the cell does not have one copy of the mom, and one copy of the dad. Each cell has 2 copies of mom, and 2 copies of the dad, causing them to be haploid.
New cards
23
During prophase 2 how many chromosomes and sister chromatids are in each haploid cell?
1 chromosome and 2 sister chromatids
New cards
24
During prophase 2, are the sister chromatids genetically identical? why or why not
they are not genetically identical, due to the crossing over in prophase 1
New cards
25
What happens in prophase 2
nuclear membrane dissolves, centrioles move to opposite poles, and spindle fibers reform
New cards
26
What happens in metaphase 2?
1 chromosome moves to the center of cell
New cards
27
In metaphase 2, what is the chromosome made of?
2 sister chromatids
New cards
28
What happens in anaphase 2?
sister chromatids separate and move to the opposite poles of the cell
New cards
29
What is the difference between anaphase 1, and anaphase 2?
in anaphase 1, the homologous chromosomes move to opposite poles of the cell, but in anaphase 2, the sister chromatids move to the opposite poles of the cell
New cards
30
Will the sister chromatids be identical in anaphase? Why or why not?
They will not be identical due to the genetic exchange that occurred while crossing over
New cards
31
What happens in telophase 2?
Nuclear membrane reforms, DNA relaxes into chromatin, and spindle fibers dissolve
New cards
32
How many haploid daughter cells will be created after cytokinesis?
4
New cards
33
Why are the haploid cells unique?
Due to the crossing over in prophase, and the meeting in the center in metaphase
Studied by 24 people
