D oxygen there was no free oxygen on the earth
Lethal alleles cause the death of an organism prenatal or after the birth. Lethal alleles are usually a consequence of a mutation and they can be recessive, dominant or conditional. Since the lethal dominant alleles are harmful whether they are carried in homozygous (e.g.AA) or heterozygous (e.g.Aa) form, a strong selection against them is present and thus these alleles are much more rare.
Depending on what happens with the environment if its a decline in resources it could completely fall and tear itself apart it just depends really on what you think of just make up a situation in your head and talk about that
<span>Nitrogen and phosphorous are the most prevalent aquatic pollution and contribute heavily to the excessive growth of algae in aquatic environments called algae blooms. The nitrogen from the fertilizers is found in molecules called nitrates which are compounds of both oxygen and nitrogen. Phosphorous helps algae to absorb carbon dioxide. So when the phosphorous levels are high the algae absorbs more carbon dioxide, which allows for faster photosynthesis and faster glucose production which leads to faster growth. Although algae need both nitrogen and phosphorous to grow, when the levels are too high the algae grows faster than the ecosystem can sustain leading to oxygen deprivation for the other aquatic organisms.</span>
