<span>Natural selection is likely when there are stronger selection pressures. For example, a perpetual selection pressure is the fact that organisms have to compete for food and resources, meaning the best adapted ones survive. However, a stronger selection pressure may cause natural selection to occur more obviously. An example of this is when the number of white peppered moths decreased during industrialization in England due to the soot collecting on the trees. The change in population was very fast and obvious.</span>
Answer:
number 1 answer is 3.
number 2 energy is flowing upwards. ex grasshopper eats the grass, rat or whatever that is eats the grasshopper, and the hawk eats the rat. energy is going up each trophic level.
number 3. if the grass became polluted, then animals would get pollution in their bodies and at some point would die. eventually the grass would die too. primary consumers such as mouse, rabbit, grasshopper/snails would accumulate the most pollution because they directly eat the grass. whatever that is in the grass goes straight into their bodies.
Answer should be A if multiple choice
They add nitrogen to the soul through their nodules !