Glacier bears are an Alaskan subspecies of the American black bear. Glacier bears have a rare dark grayish-blue fur. Some glacier bears live in the same areas as black bears. A glacier bear and a black bear can mate and produce cubs. Studies show that the allele for black fur is dominant and the allele for gray-blue fur is recessive. The gene for fur color can be represented by the letter G or g. The genotype for gray-blue glacier bears is . *

links? do you have a link? i don't see anything?

the earth is thought to have been formed about 4.6 billion years ago by collisions from a cloud of hydrogen, helium, rock, ice and other materials. these were pulled together by gravity to form objects in and around earth like- asteroids and small early planets called planetesimals.

so, the best possible answer to this question will be option d- to harden materials to form different parts of earth’s layers