Because the interior of the lipid bilayer contains the nonpolar , only small nonpolar substances are able to diffuse directly across the cell membrane.

Explain the importance of producers, primary consumers, secondary consumers and decomposers in an ecosystem.

The development of_ factored in the development of complex organisms.

Which of the following is a consequence of urban heat islands? increased precipitation downwind of the city? increased precipitation upwind of the city? decreased winds within the city? increased winds within the city?