Transcript 04-From Cell Division to Tumour - Alexmac

From Cell Division to Tumour
Cell Growth
• The Cell Grows
• New Organelles are made
• The DNA Duplicates
Cell Growth
• The Cell Grows
• New Organelles are made
• The DNA Duplicates
Interphase!
The Chromosomes Thicken
• The chromosomes thicken.
• The chromosomes made up of
two chromatids.
• Nuclear membrane dissolving.
The Chromosomes Thicken
• The chromosomes thicken.
• The chromosomes made up of
two chromatids.
• Nuclear membrane dissolving
Prophase!
Lined-Up
• The chromosomes line up in the middle.
• Nuclear membrane completely dissolved.
Lined-Up
• The chromosomes line up in the middle.
• Nuclear membrane completely dissolved.
Metaphase!
Separation
• The chromatids separate
• Each of the daughter chromatids pulled to
opposite sides of the cell.
Separation
• The chromatids separate
• Each of the daughter chromatids pulled to
opposite sides of the cell.
Anaphase!
It’s just a pinch
• Chromosomes reach opposite sides
• A new nuclear membrane formed around
each group of chromosomes
• The cell membrane starts to pinch in the
middle.
It’s just a pinch
• Chromosomes reach opposite sides
• A new nuclear membrane formed around
each group of chromosomes
• The cell membrane starts to pinch in the
middle.
Telophase!
And they’re off on their own
• The pinching off is complete.
• The membrane separates giving rise to two
new daughter cells
And they’re off on their own
• The pinching off is complete.
• The membrane separates giving rise to two
new daughter cells
Cytokinesis !
The Cell Division Story
Cell Division on overdrive
• Sometimes cell division gets out of hand.
• A mass of cells continue to divide without any
benefit to the body.
• A lump of cells is formed- a Tumour
Benign Tumour
• A benign tumor does not affect the cells
around it.
• The surrounding cells maybe crowded and
squished, but they continue performing their
functions.
Malignant Tumour
• It interferes with the work of the cells around
it.
• May destroy the cells around it.
• Some malignant tumour cells can break away
and travel to other parts of body.
Cancer and its Causes
• Cancer is a group of diseases that leads to uncontrolled
cell division and the formation of a cell lump, a
malignant tumour (a malignant tumour cell is said to
be cancerous)
• Carcinogens- Environmental factors that cause cancer
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Tobacco smoke
X-rays (repeated exposure)
Environmental pollution
UV radiation (sunlight or tanning beds)
Some organic solvents
Some chemicals (eg. Bi sphenol A -BPA- in plastic bottles)
• Cancer by heredity – The DNA passed from
one generation to the next may be damaged.
• Cancer by mutation – random changes in
DNA.
Detection and Diagnosis
• Moles: Indicators of Skin Cancer
Detection and Diagnosis
• X-Rays: can detect cancer in bone, muscles
and some organs.
Detection and Diagnosis
• Mammograms: a type of X-Ray used for breast
cancer detection, and regular screening.
Detection and diagnosis
• Biopsy- A small portion of a suspected tumour
is surgically removed, and the cells are
compared to normal cells. Differences in size
and shape are used to determine if the cells
removed are cancerous.
Cancer Treatment