Molecules are attracted to one another by Van Der waals forces. How does Van der Waals forces compare with ionic and covalent bonds

How do tides affect the organisms living in intertidal zones? a. no organisms live in intertidal zones due to the tumultuous environment. b. the mechanical forces of the waves keeps the organisms clean. c. only plants live in intertidal zones because the animals float away with the waves and never return. d. the mechanical forces of the waves can dislodge the organisms from their habitat.

Which direction does the energy flow in this energy pyramid ?

How do the evolutionary chart and the video support the claim that all living things are made up of cells?