The endosymbiosis explains how eukaryotic cells may have evolved from prokaryotic cells.
The earth's atmosphere consists mainly of nitrogen and oxygen with smaller proportions of other gases such as carbon dioxide. The amount of carbon dioxide in the atmosphere is maintained through a balance between processes such as photosynthesis, respiration and combustion. However this balance is being affected by human activities which are polluting the atmosphere.
The proportion of these gases in the atmosphere is as follows: nitrogen is the most abundant at 78%, oxygen is next at 21%, while others include carbon dioxide at 0.037% and argon at 0.9 % .
MUTATIONS lead to duplications actually increase the number of genes in a genome.
I think its anaerobic respiration
A clade is a group of organisms that includes an ancestor and all of its descendants. Clades are based on cladistics. This is a method of comparing traits in related species to determine ancestor-descendant relationships. Clades are represented by cladograms, like the one in Figure below.
