CH 10

Bacteria divive by

binary fission

Humans have 23 pairs of

homologous chromosomes

Eukaryotes have 10 to 50

chromosomes

Humans have 46

chromosomes

Haploid vs Diploid

H(n)- one set of chromosomes

D(2n): two complete sets of chromosomes (46 total chormosomes)

Chromosomes are

composed of chromatin, comlex of DNA and protein

single uninterrupted strand of DNA

Structural maintenance of chromosomes (SMC)

critical for proper cell division, proteint that help dna and cause corrrect folding

Sister chromatids are what

2 identical DNA molecules

What does Cohesin do?

connect the chromosomes at the centromeres

Kinetochore allows for what

attachment to microtubules

Cell cycle

G1 phase

S phase

G2

M phase

C phase

G1 phase

growth phase, longest phase

S phase (synthesis)

replicatio of DNA

G2 phase

more growth preparing for mitosis

Time it takes to complete a cell cycle varies greatly

fruit fly embryos complete in 8 min

2 irreversible points

1. replication of genetic material

   1. seperation of sister chromatinds

G1/S checkpoint

enviromental signals

external signal incluence

checks factors if cell can move on

G2/M

DNA integrity

checks success of DNA replication

Spindle checkpoint

ensures that all chromosomes are attached to spindle

Cdks

enzymes that turn regulator proteins on/off

Cycling pair with cdks to

activate the cdks and direct tehm to target regulator proteins

Growth factors

trigger intacellular signaling system

Tyrosine kinase (RTK)

GF

initiates kinase cascade that stimulates cell division