Answer:Greenhouse gases allow thermal energy to pass through the atmosphere and back out into space
Explanation:
Because the three-horned alien is heterozygous, we know that three must be dominant to four, because the gene for the three horns is "hiding" the gene for four horns. Therefore, the three-horned alien has the genotype Tt (T for three horns, and t for four horns). The four horned alien must be tt, because that is the only way that a recessive trait may be seen. If you solve the punnet square on a cross between Tt and tt, you end up with half three (heterozygous) and half four (homozygous recessive) it is a bit easier to explain with something a little "closer to home" if you want me to explain it again, just say so, I don't mind!
Easier for diffusion to take place
Scientists believe that at first these bears scavenged seal carcasses that had washed ashore, and gradually began to hunt the seals by waiting at the water's edge as the seals surfaced to breathe. This is believed to be an important step in the evolution of a new bear species, the polar bear
Over time the new polar bears were used to the cold climate and learnt how to fish, they then separated from the grizzly bears, they developed new creatures which would help them survive in one of the most dangerous climate.