Terms in this set (21)
Chromosomes that have the same sequence of genes, that have the same structure, and that pair during meiosis - one from mom and one from dad.
A cell that contains two sets of chromosomes; one inherited from the mother and one inherited from the father. Most body cells (nerve, brain, muscle, skin, etc.) are considered diploid cell. (represented by 2n)
A cell that contains only one set of chromosomes instead of the normal pair. Gametes, which are sex cells like sperm and eggs, are haploid cells.
diploid body cells (everything except egg and sperm)
Haploid sex cells. The result of meiosis is 4 gametes, or sex cells, that each contain half of the genetic information in the parent organism.
cell grows and Chromosomes (uncondensed in this phase) replicate in preparation for meiosis. At this point they are long and thing and called "chromatin".
Homologous chromosomes pair, crossing over occurs(exchange of genetic material) ; nucleus breaks down
homologous chromosomes line up at the equator of the cell. The centromere of each chromatid pair attaches to one spindle fibre.
Homologous chromosomes, in tetrad, exchange genetic material. Process in which homologous chromosomes exchange portions of their chromatids during meiosis. This increases genetic variation.
formation of tetrads
Homologous chromosomes separate and move to opposite poles. Note that chromatids do not separate - each duplicated chromosome still has two chromatids.
chromosomes uncoil, two nuclei form; The cytoplasm divides and two new haploid cells form. Each new cell has one duplicated chromosome from each similar pair.
chromosomes condense in each new cell. The duplicated chromosomes and spindle fibers reappear in each new cell.
The duplicated chromosomes move to the centre or equator of the cell. Each centromere attaches to two spindle fibres instead of one.
The centromere divides. The chromatids seperate and move to opposite ends of the cell. Each chromatid is now an individual chromosome.
The spindle fibres disappear, and a nuclear membrane forms around each set of chromosomes; cells divide, 4 haploid cells are formed
Chromosomes duplicate before dividing in meiosis.
Error in meiosis in which homologous chromosomes fail to separate, resulting in gametes with too many or too few chromosomes
Male gamete (sex cell)
Female gamete (sex cell)
A process in cell division during which the number of chromosomes decreases to half the original number. It occurs by two divisions of the nucleus and results in the production of 4 sex cells (gametes).