Meiosis Flashcards
Homologous chromosomes
Chromosomes that have a corresponding chromosomes from the opposite sex parent
Definition of meiosis
A process of reduction division that produces gametes in which the number of chromosomes per cell cut in half (haploid) through the separation of homologous chromosomes
What is a diploid cell
A cell that contains both sets of homologous chromosomes is diploid which means two sets
What is a haploid cell
A cell that contains only one set of chromosomes is haploid
Cell cycle of meiosis
Interphase
Meiosis 1 and 2
Cytokinesis
Interphase cycle
G1- cell grows protein production
S- DNA replication
G2- production of new organelles including centrioles
What happens in prophase 1
Chromatin coils into chromatids and the homologous pairs of chromatids come together to form a tetrad
What is crossing over and why is it important
Crossing over occurs when portions of the homologous chromosomes are exchanged
Crossing over allows for the random mixing of genes which adds genetic variety
Anaphase 1
Homologous chromosomes separate and are pulled to the poles
Centromeres do not split
Telophase 1 and cytokinesis
Chromosomes uncoil, spindle breaks Down. The nuclear membranes and nucleoli reform
Cytoplasm divides to form two cells
Why is there no interphase between meiosis 1 and 2
So that each new cell will only have half (haploid) the number of chromosomes as the original parent cell
Second part of meiosis
Just like mitosis but here are half the number of chromosomes
Third source of genetic variation
Random fertilization of the egg and sperm
What is the end result of meiosis
Four genetically different haploid cells that contain half the number of chromosomes as the original parent cell
End result of mitosis
Two genetically identical diploid cells that are identical to the original parent cell
