The answer is: <span>Ecological Succession
</span><span>If I managed to help you, please make sure to mark my answer as the "Brainliest" answer. Thanks! :)</span>
The first one, <span>By having white blood cells to attack pathogens. this is because blood also has white blood cells. and the immune system has pathogens. so the blood cells help attack pathogens.</span>
<span>Plants take nitrogen from the soil by absorbing through there roots as amino acids Most nitrogen obtained trerrestrial animals can be traced back to the eatinf of plants at some stage of the food chain. hope this helps!</span>
And endocrine cell is an outer cell i think and a target cell is an antibody which helps attack viruses
