Describe what is happening in figures 1-3

There are less white mice in the third box because the bird has already been there. But it is harder for it to see the dark mouse so they are safer and more of them are left. In the second box the bird is holding a white mouse. But the first and second boxes have about the same numbers of mice because the bird already has one

Explanation:

dna is made up of six smaller molecules -- a five carbon sugar called deoxyribose, a phosphate molecule and four different nitrogenous bases (adenine, thymine, cytosine and guanine).

the answer is 100% density i've answered this question before and done the quiz myself.