Download Grade 10 Applied Science – Biology

Grade 10 Applied Science – Biology
Cancer and Specialized Cells
Cancer – The Cell Cycle Gone Wrong
 Occasionally, a mutation in the DNA occurs. This mutation alters the cell cycle and can create
cancer cells. The cells do NOT die, and they begin to divide and divide and divide.
 Cancer is a broad group of diseases that result from uncontrolled cell division.
 Cancer can be inherited (i.e., genetic) or caused by environmental factors (e.g., poor lifestyle,
virus).
 Uncontrolled cell division can lead to a tumour. A TUMOUR is a mass of cells that continue to
divide and increase in number without any obvious function to the body.
 There are two tumour classes: (1) Benign and (2) Malignant.
 A Benign Tumour does NOT affect the surrounding cells.
 A Malignant Tumour interferes with the function of the surrounding cells. Malignant Tumours
are cancerous. They are dangerous because their cells can break away from the tumour and
move to other parts of the body to form a new tumour.
 Do you eat 5-12 servings of fruits and vegetables each day? If not, you may be missing fibre,
vitamins and natural cancer-fighting compounds called ANTITOXIDANTS. A healthy diet helps to
reduce the risk of some cancers. These SUPERFOODS include tomatoes, carrots, broccoli and
red grapes.
 Ultraviolet Radiation (UV) is a leading cause of skin cancer. UV mutates skin cells. UV includes
UVA and UVB radiation.
 UVA causes the skin to tan. Tanning salons use UVA radiation. UVA rays penetrate deeply
into the skin and can increase the risk of melanoma, a deadly skin cancer.
 UVB rays cause burning and make the skin look red. UVB rays do not penetrate the skin as
deeply as UVA rays.
Detecting Cancer
Many people develop moles. Very few moles are cancerous, but some moles can become malignant
tumours. You can easily detect certain cancers using ABCD. If you know your body, you will also notice
any new or unusual lumps or marks.
Term
Benign
Malignant
A
Asymmetry
Shape is similar throughout
Shape is odd, not similar throughout
B
Border
Border is even throughout
Border is ragged
C
Colour
Uniform colour throughout
Uneven colour
D
Diameter
< 6 mm
> 6 mm (About the size of a penny)
Specialized Cells
 You began life as a single fertilized egg cell. It quickly divided to form two identical daughter
cells. After ten days of cell divisions, some cells start to DIFFERENTIATE. At 22 days, some
cells that became your heart began to beat.
 Differentiated cells are called SPECIALIZED CELLS. These cells perform a specific function.
 Red Blood Cells deliver oxygen and remove carbon dioxide from the muscles
 Fat Cells store energy in the form of fat
 Skeletal Muscle Cells contract to allow for movement
 Nerve Cells conduct electrical impulses and coordinate activity.
 Your body has many different kinds of cells that work together. Your body has more than 200
different kinds of Specialized Cells (…all controlled by your brain).
 Each type of Specialized Cell is a particular shape and size, and it has unique features that let the
cell perform its function. For example, Red Blood Cells have rounded edges so they flow easily
through blood vessels.
To learn more about Specialized Cells, you can watch a You Tube video “Specialized Cells and Tissues
at http://www.youtube.com/watch?v=I8uXewS9dJU