Ch. 10 Bio Study Guide

CANCER

Cancer → uncontrolled cell division caused by mutations in cell cycle genes

CELL FATE

Cell division → cell makes new identical cells
Differentiation → cell becomes specialized and stops dividing
Apoptosis → programmed cell death

Difference between each → divide = make more cells, differentiate = specialize, apoptosis = die

Phase cells enter if they differentiate → G0 phase

When apoptosis happens → when cells are damaged, old, or dangerous

WHY CELLS DIVIDE

Development → growth of organism
Cell replacement → replace old/dead cells
Repair → fix damaged tissue

CELL CYCLE PHASES

G1 → cell grows and does normal functions
G0 → resting phase (not dividing)
S → DNA is copied
G2 → prepares for division
M → mitosis (cell divides)

S PHASE

S phase → DNA replication happens
Sister chromatids → identical copies of DNA
Centromere → holds sister chromatids together

M PHASE

M phase → nucleus divides (mitosis) and cell splits

CELL CYCLE REGULATION

Cell cycle checkpoints → control system that checks if cell is ready to move on
Purpose → prevents damaged cells from dividing

MITOSIS STEPS

Prophase → chromosomes condense, nuclear membrane breaks down
Metaphase → chromosomes line up in middle
Anaphase → sister chromatids pull apart
Telophase → two new nuclei form

CYTOKINESIS

Cytokinesis → cytoplasm divides → 2 identical cells form

CANCER & CELL CYCLE

Cause of cancer → mutations in genes controlling cell cycle
Result → checkpoints fail → cells divide uncontrollably