cell cycle and mitosis

why do cells divide

growth - tree growing

repair - replace old cells when cells become damaged

reproduction- to make new cells

how do cells divide

binary fission

bi- two

fission- to split

drawing of binary fission

mitossis

division for growth and repair

body cells

Meiosis

division for reproduction

DNA terminology: DNA

Double stranded molecule, made of nucleotides, stores genetic info

Chromatin

loosely arranged dna arranged in nucleus when the cell in not dividing

Chromosome

DNA that is highly condensed and appears as solid structures during cell division

Chromatid

½ of a newly copied chromosome (same)

Centromere

Region of the chromosome that holds the chromatids together during mitosis

what type of cells dont divide

nerve cells, cardiac muscle cells

they dont deid because they are their fuctions are highly specifalized so if they stop its life losing 

(such as brain)

do all cells divide and what are the life spans

life spans of cells differ and not all cells divide and the same time

Interphase

the growth, reproduction of DNA, and normal activities when a cell is not dividing

G1, S, G2 are all considered

interphase

G1

cell growth + normal cell activities

S

synthesis (DNA is copied)

synthesis means to make

G2

cell continues to grow, prep for mitosis

M and C are considered

cell division

M is made of

prophase, metaphase, anaphase, telophase

PMAT

C

CYTOokinesis (when the CYTOplasm and cell split into two new daughter cells

Prophase

Chromatin → Chromosomes

nuclear membrane and nucleolus break down

centrosome move upwards to oppo poles

spindle fibers begin to form

Metaphase

(middle)

spindle fibers attach to the centromeres. Chromosomes align along the middle of the cell.

Anaphase

sister chromatids separate from each other

they are pulled to opposite poles.

telophase

a set of identical chromosomes at each pole

nuclear membrane begins to reform

chromosomes uncoil

spindle fibers disappear

opposite of prophase

cytokinesis

the cytoplasm divides into two daughter cells.

how is cytokinesis different in plants and animals

animals- furrow of trench forms in the middle of the cell

plant- a cell plate forms between the dividing cells (a new cell wall forms on each of the new cells).