Meiosis Flashcards
(19 cards)
1
Q
Gamete
A
a male or female reproductive cell (egg, sperm)
2
Q
Zygote
A
a cell formed by the fusion of two gametes
3
Q
Haploid
A
a cell that contains half the number of chromosomes as the parent cell
4
Q
Diploid
A
a cell that contains pairs of homologous chromosomes
5
Q
Synapsis
A
the alignment of homologous chromosomes during prophase |
6
Q
Homologous Chromosome
A
a chromosome that contains the same sequence of genes as another chromosome
7
Q
Spermatogenesis
A
the process of producing male gametes (sperm)
8
Q
Oogenesis
A
the process of producing female gametes (eggs)
9
Q
Crossing Over
A
the exchange of chromosomal segments between a pair of homologous chromosomes
10
Q
Interphase
A
- G1, S, G2
- parent cell contains duplicated chromosomes
sister chromatids held by centromeres
11
Q
Prophase |
A
- centromeres move to piles of the cell
- synapsis
- none sister chromatids cross over to exchange genes
12
Q
Metaphase |
A
- spindle fivers attach to the centromere of each chromosome
- homologous pairs of chromosomes line up in 2 rows at the cell’s equator
13
Q
Anaphase |
A
- homologous chromosomes separate to opposite poles of the cell
- pulled by the shortening of spindle fibers
centromeres are still in tact
14
Q
Telophase |
A
- homologous chromosomes uncoil
- spindle fibers disappear
- nuclear envelope and nucleus reappear
- cytokinesis follows telophase |
- two cells form, each carrying chromosomes which are made up of 2 chromatids
15
Q
Prophase ||
A
- chromatin condenses
- centrosomes begin to form spindle fibers
- nuclear membrane and nucleus disappear
16
Q
Metaphase ||
A
- chromosomes move to the equator of the cell
- spindle fibers attatch to the centromeres of each chromosome
17
Q
Anaphase ||
A
- centromeres split
- sister chromatids are pulled apart by spindle fibers to opposite poles of the cell
18
Q
Telophase ||
A
- spindle fibers disintegrate
- chromosomes de-condense into chromatin
- nuclear envelope re forms around the new sets of chromosomes
- cytokines follows telophase ||
- 4 genetically different haploid daughter cells form
• will then develope into egg or sperm
• each human cell will have 23 single chromosome strands
19
Q
Meiosis increases genetic variation by…
A
- independent assortment of homologous chromosomes and chromatids
- crossing over
- random fertilization of egg
