Acaterpillar spends its morning eating grass. in the afternoon, a robin eats the caterpillar. approximately what percentage of the energy in the grass was transferred to the robin. a. 90% b. 10% c. 0.1% d. 1%

the answer is true when observing or determining population size, a direct observation is use, in which each organism is counted in a population or in an area. one benefit of this measure is that you get the exact population count but it will take a long time to  determine  the  size  of a  population.