Mitosis and CancerMitosis and CancerChapter 5, Section 2Chapter 5, Section 2

In your textbookIn your textbook

http://www.hybridmedicalanimation.com/anim_mitosis.htmlhttp://www.hybridmedicalanimation.com/anim_mitosis.html

ProphaseProphase

Nuclear envelope disintegratesNuclear envelope disintegrates Chromosomes condenseChromosomes condense Centrioles – paired structures Centrioles – paired structures

that produce spindle fibers – that produce spindle fibers – begin moving toward opposite begin moving toward opposite poles (sides) of the cellpoles (sides) of the cell

Video clip – 3:47

MetaphaseMetaphase

Chromosomes line up Chromosomes line up along the equator along the equator (midline) of the cell(midline) of the cell

Spindle fibers extend Spindle fibers extend from centrioles and from centrioles and attach to chromosomes attach to chromosomes at the centromereat the centromere Video clip – 0:28

AnaphaseAnaphase

Spindle fibers Spindle fibers separate separate chromosomes at the chromosomes at the centromere and pull centromere and pull sister chromatids to sister chromatids to opposite poles of opposite poles of the cellthe cell Video clip – 0:38

TelophaseTelophase Nuclear envelopes form Nuclear envelopes form

around each set of around each set of genetic materialgenetic material

Spindle fibers Spindle fibers disappeardisappear

Cytoplasm may begin Cytoplasm may begin to pinch in near the to pinch in near the center of the cell (the center of the cell (the mechanism for this is mechanism for this is different in plants than different in plants than animals)animals)

Video clip – 1:13

CytokinesisCytokinesis the division of the cytoplasm – almost the division of the cytoplasm – almost

always follows telophase.always follows telophase. differences in cytokinesis between plant differences in cytokinesis between plant

and animal cells because of the cell wall in and animal cells because of the cell wall in plants (animal cells only have a cell plants (animal cells only have a cell membrane).membrane).

Occurs when cells begin to divide Occurs when cells begin to divide uncontrollablyuncontrollably

CancerCancer

Cancer (cont’d)Cancer (cont’d)

In normal tissue, there is a balance In normal tissue, there is a balance between new cell growth and old cell between new cell growth and old cell death.death.

In cancer cells, that balance is disrupted – In cancer cells, that balance is disrupted – so a growing mass of tissue developsso a growing mass of tissue develops

This mass of tissue is called a tumor.This mass of tissue is called a tumor. BenignBenign = non-cancerous = non-cancerous MalignantMalignant = cancerous = cancerous Video clip – 3:10Video clip – 3:10

Cancer (cont’d)Cancer (cont’d)

Malignant (cancerous) tumors are Malignant (cancerous) tumors are dangerous because they can:dangerous because they can: invade the organsinvade the organs interfere with the functions of these interfere with the functions of these

organs.organs.

Types of CancerTypes of Cancer

CarcinomasCarcinomas = = most common types; arise most common types; arise from the cells that cover external and from the cells that cover external and internal body surfaces. Ex: Lung, breast, internal body surfaces. Ex: Lung, breast, colon colon

SarcomasSarcomas = arise from cells found in the = arise from cells found in the supporting tissues of the body. Ex: bone, supporting tissues of the body. Ex: bone, cartilage, fat, connective tissue, and cartilage, fat, connective tissue, and muscle. muscle.

Types of Cancer, cont’dTypes of Cancer, cont’d

LymphomasLymphomas = cancers that arise in = cancers that arise in the lymph nodes and tissues of the the lymph nodes and tissues of the body's immune system. body's immune system.

LeukemiasLeukemias = cancers of the = cancers of the immature blood cells that grow in the immature blood cells that grow in the bone marrow.bone marrow.