Biology: Mitosis (copy)

prokaryotic reproduction divides in half, making an exact clone

interphase, mitosis, cytokinesis

one half of a duplicated chromosome a copy of a DNA molecule produced by replication

the chromosome splits into 2 identical strands of DNA called sister chromatids, connected at the centromere

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prep for mitosis, during interphase

stage when the cell is actively dividing: mitosis and cytokinesis

multicellular organisms: replace lost cells and grow single celled: reproduction

division of somatic (body) cells, specifically - division of the nucleus

first and longest stage of the cell cycle Three parts: G1, S phase, and G2

growing and normal life processes

DNA is copied

a threadlike structure that carries DNA before replication: a single chromatid after replication it has 2 chromatids connected by a centromere

'thread' that makes up chromosomes made up of protein, RNA, and DNA chromatin spins into rods, making chromosomes, during prophase

prophase, metaphase, anaphase, telophase (PMAT)

longest phase in mitosis chromatin (threads) is packaged into chromosomes (rods) to make them easier to move (in animal cells) centrioles move to opposite ends of the cell + spindle fibers form between poles nuclear membrane disappears

chromosomes line up in the middle of the cell, spindle fibers attached to centromeres of chromosomes

Chromatids separate and begin to move to the opposite ends/poles of the cell.

chromatids reach the the poles nuclear membrane starts to reform

mitosis ends

The spindle fibers that control the chromosomes in mitosis

splits the cell in two --splitting of the cytoplasm pinches the cell in half each new cell has nucleus w/ identical chromosomes

in animal cells; where cell membrane pinches to split the cell in two

plant cells have cell wall -- can't pinch in a midline dividing the cell that eventually becomes the cell wall divides the cells during cytokinesis

IPMATC Intergalactic penguins might attack, take care Interphase, (prophase, metaphase, anaphase, telophase), cytokinesis

Cells skip checkpoints and divide uncontrollably, creating tumors

checkpoints where the cell cycle stops until a go-ahead signal is received

most important checkpoint, checks for growth if signal received, will usually divide completley if signal not received, will exit cycle and enter G0 phase

nondividing state in which a cell has left the cell cycle

Growth factors Density-dependent inhibition Anchorage dependence

mass of rapidly dividing (cancerous) cells that can damage surrounding tissue

a mass of abnormal cells that remains at the site of origin

A cancerous tumor that is invasive enough to impair the functions of one or more organs (Metastasis)

The spread of cancer cells beyond their original site usually through blood stream most dangerous property of cancerous cells

smoking, drugs, alcohol uv radiation, x rays, radon gas certain chemicals (ex. asbestos) or viruses (HIV) certain hormones (excess estrogen) bad diet, no exercise, genetics, age, random chance

surgery, radiation, chemotherapy

Taxol - freezes the mitotic spindle after it forms thus stopping mitosis at metaphase Vinblastin- prevents the mitotic spindle from forming

a chromosome consists of 2 identical strands of DN called sister chromatids

• each chromatid is a copy of a DNA molecule produced by replication

• the chromatids are held together at the centromere

• Single-celled organisms use cell division for asexual reproduction

• types: meiosis and miosis