The are responsible for seeing black and white during relatively low-light conditions.

The retina of the human eye is made up of light sensitive neurons which are arranged in three layers. The first layer consists of rods and cones. The RODS are responsible for seeing black and white during relatively low-light conditions. While the cones are responsible for color vision.

i don't know. the other person does though.

thymine. in rna, thymine is replace by uracil