A venus fly trap has green leaves for photosynthesis as well as consumes insects. Explain how it has two roles in an ecosystem.

Well, photosynthesis converts CO2 into Oxygen, so it helps in that way. Also, by eating insects and decomposing them, it also helps with the carbon cycle.

Hope this helps :)

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.