1. The group nearest the end or with the shortest stem of a phylogenetic tree has evolved most recently. In this case it is eutherians.
2. The group with the longest stem has been around the longest: fish
3. A direct common ancestor will share the same immediate line, like marsupials and eutherians. Fish and marsupials do not have a common direct ancestor.
Please write out the problem you are specifying <span />
The answer is Bacteria
Prokaryotes are a microscopic single Celled organisms that has neither a distinct nucleus with a membrane nor other specialized organelles.
Answer: (A) Distilled Water
First, he should measure how long it takes for the liquid to become clear if X and Y are mixed together. Then, he should measure how long it takes if he also adds substance A to X and Y. He will find out if substance A is a catalyst.