Chapter 3.5 Flashcards
What is the physical basis for this mitotic clock?
The DNA at the tips of chromosmes called telomeres.
What happens when the telomere gets short?
When the chromosome tips shorten to a certain point, the singals the cel to cease dividing.
How is a tumor formed?
With too frequent mitoses, or those that continue unabated, produce an abnormal growth, or neoplasm with forms an disorganized mass
Two types of tumors?
BEnign and Malignant
What is a benign tumor?
It remains in a place like a lump, and will interefere with the function of healthy tissue if it enlarges
What is a malignant tumor?
It is invasive and extends into surrounding tissue.
Why are cancer cells said to be immortal?
Because they do not cease dividing at the 50 to 60 miotic division limit that other cells follows.
What are Oncogenes?
Abnormal variants of genes that normall control the cell cycle but are overexpressed increasing cell division rate.
Wha are Tumor Suppressor Genes?
Normal hold mitosis in check. Removing this leads to uncontrolled cell division leading to cancer results
