what does this mean?

Question

The Effect of White Light on the Repair Mechanism of U.V. Exposed E. coli K12

Answer 1

Somebody took strain 'K12' of the bacterium E. coli and exposed it to Ultra-Violet radiation. This person then exposed the bacterium to full-spectrum white light and tested or otherwise measured the DNA repair mechanism of the cell to see how well it worked.
Note that these tests were almost certainly done on bacterial colonies rather than single cells.
Oh, and not bad, Alex - a little confused there in spots, but you got the vitamin K bit mostly right (good old E. coli _makes_ vit. K that _we_ use)!

Answer 2

BEFORE I SAY THIS... IM IN 5th GRADE!!!

it means that the sun being "white light" functions U.V. rays which of coarse helps E.coli to survive, and E.coli uses vitamin k in our body's to help us digest our food and produces that dried blood on your skin called a blood clot which helps you not die.

Your welcome!