Bio meiosis and reproduction

Bio CP

female gamete

egg

homologous pair

same size, same centromere location, banding pattern, and genes in the same location on each pair. BUT- not the same nucleotide sequence at the same gene location.

Homozygous

2 of the same alleles (pure)

diploid (2n)

somatic body cell that contains homologous pairs

haploid (n)

sex cell that does not contain homologous pair

diploid number of human chromosomes

46

haploid number of human chromosomes

23

Mitosis

in cell division in which a diploid cell divides into two, genetically identical diploid cell.

Meiosis

special type of cell division in which diploid cell divides to create four genetically unique haploid cell

fertilization

each unique egg and sperm randomly combine to create genetically unique diploid zygote

Crossing over

when homologous chromosomes SWAP genes (DNA) when they are paired up in a tetrad (prophase 1)

Metaphase 1

homologous chromosomes (tetrad) line up in the middle. \n Spindle fiber attach to cntermere.

Anaphase 1

homologous chromosomes (tetrads) are pulled apart to opposite ends of the cell

Cytokinesis 1

contractile ring pinches the cells apart at the furrow

sexual reproduction

the combining of two sex cells (gametes) (sperm and egg)

alleles

different forms or version of the same gene (found in gene locus)

Heterozygous

2 different alleles (hybrid)

Gametes

(sex cell) the product of meiosis

male gamete

sperm

testes

sperm

ovaries

egg

interphase 1

DNA replication take place \n Cell growth and make proteins \n prepare for cell division

Prophase 1

\-DNA condense into chromosome form \n -centrioles move to the poles \n -nuclear membrane disappear \n -spindle fiber begin to form \n -homologous pair come together and cross over occurs

Telophase 1

furrow starts to form \n DNA uncoil to chromatin form \n spindle fiber disappear \n nuclear membrane reform

Prophase 11

nuclear membrane breaks down \n DNA condenses into DAC \n centrioles move to the poles \n spindle fiber begins to form

Metaphase 11

DAC line up in the middle of the cell \n spindle fiber attach to the centromere

Anaphase 11

sister chromatids pull apart to opposite ends of the cell

Telophase 11

Nuclear membrane reappear chromosomes uncoil into chromatin.

Cytokinesis 11

4 haploid unique gametes

Spermatogenesis

meiosis in male; four unique usable sperm cells

Oogenesis

meiosis in female; one usable egg and 3 polar bodies

independent assortment

random lining up of tetrads

trisomy

an extra chromosome in a karyotype

monosomy

a missing chromosome in a karyotype

nondisjunction

when chromosome of chromatids fail to separate during anaphase.

nondisjunction in Meiosis 1

homologous pair does not seperate

nondisjunction in meiosis 2

sister chromatids fail to seperate

nondisjunction in mitosis

DAC fail to seperate