What is an organism that lives on or in another organism and uses the other organism for nourishment to the detriment of the host organism?

Is a measure of the different types of organisms in a community. question options: tertiary secondary primary none of the above

Which of the following factors would not contribute to allopatric speciation? a) a population becomes geographically isolated from the parent population.b) the separated population is small, and genetic drift occurs.c) the isolated population is exposed to different selection pressures than the ancestral population.d) different mutations begin to distinguish the gene pools of the separated populations.e) gene flow between the two populations is extensive.

Does all the energy stored by the phytoplankton reach the top level of the pyramid