unit 8 bio test organization of genetic material: chromosomes and chromatin

what are chromosomes?

-tightly coiled DNA -found in nucleus during m-phase when cell is dividing -visible

what is chromatin?

-DNA in a non-dividing cell -not tightly coiled -not visible

what is a centromere?

structure that holds sister chromatids together in a chromosome

what is a histone

proteins that organize DNA, DNA is wrapped around histone spools

what is a nucleosome?

group of 8 histones →nucleosome → helix → visible chromoems

what is a homologous chromosome

chromosome pairs with same genes

what are sister chromatids?

result of DNA replication -identical duplicate DNA molecule -half of a chromosome

when do sister chromatids separate and where do they go?

they separate during anaphase, the centromere divide and the chromatids are pulled to opposite poles of the cell

what are sex chromosomes

determine gender (xx is female, xy is male)

what are autosomes

chromosome 1-22

what is a diploid cell?

has both halves of homologous pair of chromosome, full set of genetic information 2N, somatic/body cells

what is a haploid cell?

contains half of the full genetic information, only one chromosome from each homologous pair, 1N, gametes

where are gametes made?

in the gonads

what are the male gonads ?

testes

what are the female gonads?

ovaries

what are the male gametes?

sperm

what are the female gametes?

eggs (ova)

what is fertilization?

where gametes (1N) fuse to make a zygote (2N)