About 2.2 billion years ago, oxygen released by early became fairly abundant in the atmosphere, enabling the evolution of .
photosynthesis ... cellular respiration True or False

they fuse to form they have half as many chromosomes as a somatic cell of the same individual. b

me and my friend did 2

all these collisions do one thing, and that thing is explained in the last option. when dusst, rocks and ice collide, they harden and form giant layers of rocks or hard ice.

d)   to harden materials to form different parts of earth’s layers

hope it ,

bioteacher101