Https://www3.epa.gov/climatechange/kids/impacts/effects/ecosystems.html
this link might help you
Biosphere because humans and animals live
I'm pretty sure the answer would be A. Chromosomes contain one or more genes.
DNA contains the sugar deoxyribose, while RNA contains the sugar ribose. The only difference between ribose and deoxyribose is that ribose has one more -OH group than deoxyribose, which has -H attached to the second (2') carbon in the ring. DNA is a double-stranded molecule, while RNA is a single-stranded molecule.
