The cell theory follows :
Cells are the basic unit of life
All living things are composed of cells
All cells are reproduced from other cells
Hope this helps:)
~ His Cookie Monster
This is an effective strategy because different phases do not compete for food.
For example for the case of Jelly fish, After a brief period floating about in surface waters like planktons, the larvae then settles to the sea floor, attaching themselves to one end. They then develop to polyps and begin to feed and grow. In spring the polyps bud iff immature jellyfish known as ephyra larvae which then grow to mature jellyfish.
1 is the answer. Natural selection doesn’t happen quickly though. An organism has a mutation that is favorable to the environmental conditions. So others mate with them to pass on those traits and survive.