Why has so much effort been expended on studying DNA, a single molecule? One reason is that DNA could be viewed as the key to understanding life itself. Separate the following roles into those that are directly attributable to DNA and those that are not.

phylogenetic tree is the tree of life or evolution tree. it shows the different branches of evolution. the sequence goes like tissues - coelom - backbone - endoskeleton - segmentation

what are the options

rising temperatures because when water vapor in the air is cooled, it condenses. it turns back into a liquid and attaches to dust particles in the air. these very small water droplets group together to form clouds