You wish to set up a DNA microarray to study which genes are implicated in breast cancer. You fluorescently label normal breast tissue with a green fluorophore and tumor breast tissue with a red fluorophore. You see that your gene labeled SASH1 fluoresced green while your gene labeled HER2 fluoresced red. Taken together, these results indicate that:

a. SASH1 is overexpressed in breast cancer patients, whereas HER2 is underexpressed is breast cancer patients.

b. SASH1 is underexpressed in breast cancer patients, whereas HER2 is overexpressed is breast cancer patients.

c. both SASH1 and HER2 are underexpressed in tumor cells and normal cells.

d. both SASH1 and HER2 are overexpressed in tumor cells and normal cells.

SASH1 is underexpressed in breast cancer patients, whereas HER2 is overexpressed is breast cancer patients. The correct option is B.

Explanation:

Cancer is an abnormal cell growth which can occur in any part of the body. Alot of risk factors which can predispose one to cancer includes:

- smoking

- heavy alcohol consumption

- inherited genetic mutations.

When these cancer cells forms in the breast, it's known as breast cancer.

HER2(Human Epidermal Growth Factor Receptor 2) protein promotes the growth of cancer cells and located on the surface of both normal and cancer cells.

SASH1 (SAM and SH3 domain-containing protein 1) are tumor suppressor genes that are down regulated or under expressed in breast cancer.

Therefore, the gene labeled SASH1 fluoresced green while the gene labeled HER2 fluoresced red because SASH1 is underexpressed in breast cancer patients, whereas HER2 is overexpressed is breast cancer patients.

it provides an alternative energy pathway for the reaction to proceed.

a catalyst is a substance that speeds up the rate of a chemical reaction but is not consumed during the course of the reaction.

catalysts increase the rate of reaction without being used up. they do this by lowering the activation energy needed. with a catalyst, more collisions result in a reaction, so the rate of reaction increases. different reactions need different catalysts.

a catalyst works by providing an alternative reaction pathway to the reaction product. the rate of the reaction is increased as this alternative route has a lower activation energy than the reaction route not mediated by the catalyst.

condenser is used to focus in the light microscope.