Question

Why does the Mendel's third law of independent assortment come to as a 1:1:0:0 ?

Answer 1

In mendel's second law he studied the traits which were on different chromosomes so he got it as 1:1:1:1. but if both the traits happen to be on the same chromosome then the story changes. and thus the ratio becomes 1:1:0:0
if u want to have the details see this video lecture
http://ocw.mit.edu/courses/biology/7-012-introduction-to-biology-fall-2004/video-lectures/lecture-7-genetics-2/
i hope dis will help u