Meiosis - the form of cell division that creates sex cells

meiosis metaphase I

3rd stage of meiosis I; the tetrads line up in the middle of the cell

meiosis telophase 2

4 haploid cells result after cytokinesis

trait

A characteristic (for example blue eyes) that an organism can pass on to its offspring through its genes.

meiosis telophase I

A nuclear envelopes form around the chromosomes. Chromosomes uncoil. Spindles disappear.

haploid

(genetics) an organism or cell having only one complete set of chromosomes

diploid

(genetics) an organism or cell having two sets of chromosomes or twice the haploid number

bivalent

a pair of homologous chromosomes - another term for tetrad

egg cell

also called ovum; female gamete

meiosis

cell division that produces gametes (sex cells)

meiosis prophase I

chromosome pairs line up in tetrads, where crossing-over occurs

meiosis interphase

chromosomes duplicate

meiosis metaphase 2

chromosomes line up in the center of each cell like in mitosis

allele

different forms of a gene

zygote

diploid cell formed when a sperm fertilizes an egg

karyogram

shows the chromosomes of an organism in homologous pairs of decreasing length

meiosis anaphase 2

sister chromatids separate again

tetrad

structure containing 4 chromatids that forms during meiosis

sperm cell

the male gamete ( in animals), contains half the genes of a normal cell

independent assortment

the random distribution of the pairs of genes on different chromosomes to the gametes

sister chromatids

two strands of a copied chromosome joined at the middle by a centromere

daughter cells

new cells produced by cell division

gene

A segment of DNA on a chromosome that codes for a specific trait

homologous

Chromosomes that have the same sequence of genes and the same structure

replication

Copying process by which a cell duplicates its DNA

crossing-over

exchange of genetic material between homologous chromosomes during prophase I of meiosis