Which of the following results from an uncontrollable growth of abnormal cells?
a. complex disease
b. chromosomal disease
c. single-gene disease
d. immune disorder

A. complex disease

Explanation:

Some of the cells exhibit loss of control over cell cycle and become abnormal. These abnormal cells undergo uncontrollable growth due to absence of regulation over cell cycle / cell division. And uncontrolled growth of abnormal cells form a mass of cells called as tumor and can lead to cancer. Cancer can occur due to genetic as well as environmental factors and hence, is a complex disease.

"1. it should be, it has been for about 20 years, and it's really not much different in the end than breeding animals to have particular traits. there are always concerns about genetically engineered animals/plants affecting the environment in unexpected negative ways, but i can't think of an example where the fears didn't turn out to be baseless.  

first, as you point out, it would be a great advance in pharmacology, to be able to tailor drugs and their doses to me. the pros involve better medical treatment. the cons involve privacy issues like insurance companies denying coverage to people with genetic risk factors. looking at dna markers wouldn't affect the frequency of genetic diseases, but it would allow detection of them earlier. and ok, actually i suppose that if people used this information to avoid having children with genetic diseases, some might decrease in frequency."