Some Responses to TQTQ for 1-8-09

Hey thanks for the great questions. I have only enough time for a few answers now but tune in later for more.

Cintia asked why cancer cells lose their density dependent inhibition and anchorage dependence. Briefly, this is due to multiple gene mutations in the original tumor cell. Cancer likely is the result of more than one mutation and if those mutations involve genes that regulate the cell cycle, density dependent inhibition, and anchorage dependence; you have a tumor that can metastasize.

Which leads us to a question by Inwoo, what is metastasis? This is the spreading of cancer cells throughout the body. Rather than being encapsulated and a benign tumor, a metastatic tumor is malignant and spreads, this is one of the reasons they are so deadly.

Inwoo also asked why human chromosomes are purple. The answer is they are not. The chromosomes you saw in class were stained (probably with aceto orcin stain) which causes them to be purpleish-pink and easily visible.

More later,

Mr. Baker