CH 11 Mitois: Cell Reproduction

cell cycle

individual life cycle of the cell. has 7 phases.

Interphase

cell spends most of its life in this phase

G1 phase

cell increases in size and produces molecules needed for DNA replication

G0 phase

resting state for the cell during life cycle. cell doesn't divide once it reaches maturity

S phase

cell copies chromosome for DNA replication

G2 phase

produces proteins needed for division. end of interphase

mitosis

nucleus divides

cytoplasmic division

cytoplasm divides. now have 2 daughter cells

diploid

one set of chromosomes from each parent

homologous chromsomes

identical chromosomes. made during mitosis. only found in females.

checkpoint genes

look for mistakes, damage, triggers etc. to stop or proceed with cell life cycle

apoptosis

self destruct button for cell death. triggered by major mistakes that checkpoint genes can't fix.

asexual reproduction

single parent makes identical offspring

stages of mitosis

prophase, metaphase, anaphase, telophase

prophase

chromosomes duplicate and thicken. centrosomes move to opposite sides of the cell

metaphase

chromosomes line up in the middle of the cell. each sister chromatid is anchored to a chromosome on each side

anaphase

sister chromatids are pulled towards centrosomes and split in 2

telophase

chromatids arrive at opposite ends of cell. nucleus encloses each chromatid. cell elongates and splits in 2.

telomeres

regions of noncoding DNA @ ends of chromosomes

age and telomeres

telomeres act as a cushion to protect genes in DNA. as a cell gets older the telomeres shorten until they're too short and the cell dies.

these cells have no limit to the amount they can divide

stem cells, cancer cells

neoplasm

accumulation of abnormally dividing cells

metastasis

malignant neoplasms spreading to other parts of the body

cancer

disease when a malignant neoplasm disrupts body tissues

benign

neoplasms that stay where they are. they don't spread, grow slowly, and don't negatively effect health

malignant

neoplasms that are dangerous to health. Grow fast and get worse