AP bio unit 5: heredity

mitosis

cell division that leads to 2 duplicated cells

meiosis

cell division that leads to 4 haploid cells; creates gametes for later sexual reproduction

homologous chromosomes

chromosomes with similar size/shape/genetic information (genes are in the same order/location); one from each parent

prophase 1

chromosomes condense, pair up (w/ homologous chromosome pair), and exchange fragments of DNA by “crossing over” → variations in genetic information → genetic diversity

metaphase 1

chromosomes are pulled towards middle of cell (metaphase plate) by spindle fibers

anaphase 1

chromosomes get pulled apart

telophase 1

chromosomes reach opposite ends of cell, cell membrane splits + reforms to create 2 distinct cells

cytokinesis

the final splitting/division of the cytoplasm of a cell

anaphase 2

chromosomes condense, centrosomes move apart + form spindle

metaphase 2

chromosomes are pulled by microtubules to line up at metaphase plate

anaphase 2

sister chromatids of each chromosome are pulled apart

telophase 2

cell membrane reforms to create 2 distinct haploid cell

sister chromatids

2 copies of chromosome attached at centromere; produced during DNA replication

input of meiosis 1

diploid cell with 2 sets of chromosomes (each with 2 chromatids)

output of meiosis 1

2 haploid cells, each with 1 set of chromosomes (each with 2 chromatids)

output of meiosis 2

4 haploid cells, each with 1 set of chromosomes (each with 1 chromatid)