Is the vertical structure continuous as one moves through the ecosystem or are there locations where it changes significantly?

Which element is used in photosynthesis found in atmosphere and fixed by bacteria?

Long-period comets come from the oort cloud particles in earth’s atmosphere material from the asteroid belt the kuiper belt

In cattle a single gene with two alleles determines fur color the fur can be red white or roan roan fur has both red and white hair which of the following statements is true a the allele for roan fur color is dominant over red and white fur color b the allele for red fur color is dominant over white and roan fur color c the roan and white alleles are expressed independently of the other d the red and white alleles are expressed independently of each other