You should draw these simple Punnett Squares as it's easy to see the answers:
1. Crossing RR x Rr results in all (100%) red cow offspring. 50% will be RR (homozygous dominant), 50% will be Rr (heterozygous).
2. Crossing Rr x Rr results in 3 red offspring (75%) and 1 white (25%). Genotypes though will be 25% RR, 50% Rr, and 25% rr.
3. Crossing rr x rr will result in 100% white offspring. All offspring will be rr.
Answer:
The trapping of the sun's warmth in a planets lower atmosphere
