Adaptation through natural selection
<span>Nitrogen fixation
This process creates organic compounds, including ammonium, that contribute to the growth of a plant in much the way fertilizer does. Many plants have evolved to facilitate nitrogen fixing bacteria in their roots as to promote production of these organic compounds when the soil quality is poor or lacking in these bacteria.</span>
Answer:
Third one down
Explanation:
RR is heterozygous dominant and Rr is heterozygous recessive
