Chapter 2

cytogenetics

study of microscopic variation of chromosomes

difference between somatic and germ cells

somatic - mitosis and body cells

germ - meiosis and gametes

preparation of a karyotype

pull blood then treat with colchicine which stops cell in mitosis → centrifuge → remove plasma → put in hypotonic solution → centrifuge → put on slide → karyotype created

homologous pair

same size, band pattern, genes (not always alleles)

locus

location of gene on chromosome

genotypes

capitalized = dominant

lower case = recessive

double caps = homozygous

cap and lower case = heterozygous

asexual reproduction

unicellular organisms make new individuals

binary fission

DNA does not change across the organism

asexual reproduction

cell cycle

interphase → longest phase

m-phase (mitosis) → 1. prophase 2. pro-metaphase 3. metaphase 4. anaphase 5. telophase

interphase (longest)

G0 → no growth or division

G1 → cell growth

S → chromosomes replicated → sister chromatids made → (originally two chromosomes together to make one set then replications made of both to make 4 sister chromatids)

G2 → cell is growing

m-phase (mitosis)

prophase

pro-metaphase

metaphase

anaphase

telophase