Answer:
Nitrogen is present in the atmosphere in a molecule form about 78 percent. This nitrogen comes to the earth with the water through rainfall. Some nitrogen fix by beneficial microorganisms such as Cyanobacteria and Azotobactor which are present in the roots of higher plants. These microorganisms convert nitrogen molecule into nitrates and used by the plants. There are some other microorganisms which again convert nitrate into nitrogen molecules, called denitrifying bacteria and nitrogen molecule goes to the atmosphere again and complete the cycle.
Mitochondrion is found outside of nucleus in animal cell .
So , i think the answer is B.
In an experiment, using the elodea stalk, you are able to expose more underlying tissue and the process can be executed more quickly and it's easy to replicate the natural position for a more realistic result.
hope this helps
Natural selection is where positive traits survive more, allowing those to become more common. Mutation is where radioactivity changes genes in a random way. Natural selection allows positive mutation to become more common. Adaptation is where natural selection works for a species specifically more a new habitat.
