Transcript Mitosis

Mitosis and Cancer
Chapter 5, Section 2
In your textbook
http://www.hybridmedicalanimation.com/anim_mitosis.html
Prophase
 Nuclear envelope disintegrates
 Chromosomes condense
 Centrioles – paired structures
that produce spindle fibers –
begin moving toward opposite
poles (sides) of the cell
Video clip – 3:47
Metaphase
 Chromosomes line up
along the equator
(midline) of the cell
 Spindle fibers extend
from centrioles and
attach to chromosomes
at the centromere
Video clip – 0:28
Anaphase
 Spindle fibers
separate
chromosomes at the
centromere and pull
sister chromatids to
opposite poles of
the cell
Video clip – 0:38
Telophase
 Nuclear envelopes
form around each set
of genetic material
 Spindle fibers
disappear
 Cytoplasm may begin
to pinch in near the
center of the cell (the
mechanism for this is
different in plants than
animals)
Video clip – 1:13
Cytokinesis
 the division of the cytoplasm – almost
always follows telophase.
 differences in cytokinesis between plant
and animal cells because of the cell wall in
plants (animal cells only have a cell
membrane).
Cancer
 Occurs when cells begin to divide
uncontrollably
Cancer (cont’d)
 In normal tissue, there is a balance
between new cell growth and old cell
death.
 In cancer cells, that balance is disrupted –
so a growing mass of tissue develops
 This mass of tissue is called a tumor.
 Benign = non-cancerous
 Malignant = cancerous
 Video clip – 3:10
Cancer (cont’d)
 Malignant (cancerous) tumors are
dangerous because they can:
 invade the organs
 interfere with the functions of these
organs.
Types of Cancer
 Carcinomas = most common types; arise
from the cells that cover external and
internal body surfaces. Ex: Lung, breast,
colon
 Sarcomas = arise from cells found in the
supporting tissues of the body. Ex: bone,
cartilage, fat, connective tissue, and
muscle.
Types of Cancer, cont’d
 Lymphomas = cancers that arise in
the lymph nodes and tissues of the
body's immune system.
 Leukemias = cancers of the
immature blood cells that grow in the
bone marrow.