This process is called Denitrification. The process is undertaken by the denitrifying bacteria, whose action is converting nitrates in the soil to free atmospheric nitrogen and therefore, depleting soil fertility and reducing agricultural productivity. Examples of denitrifying bacteria are thiobacillus denitrificans, micrococcus denitrificans among others.
The species was a keystone species.
Keystone species are the species that ''hold the ecosystem together''.
They have an important role in the trophic networks (food chains) and often they can even afflict changes in the abiotic part of the ecosystem (change the composition of soil, purify the water, lower the effect of the wind etc)
Therefore, when a keystone species is removed it affects greatly the whole ecosystem.
F is your answer. Transform Boundary
Well, when chromosomes cross over during prophase 1 of meiosis, the homologous pair of chromosomes exchange segments of DNA which happen to be the genes. So the significance of crossing-over during prophase 1 is that it adds genetic variation to sexually reproducing organisms.
Answer:С) Cells from two organisms combine.
Explanation:Only in sexual reproduction 2 germ cell combine to a organisms