Which of the following is true about a polar amino acid and cellulose?
a. both are polysaccharides.
b. both contain nitrogen.
c. both are hydrophobic.
d. both contain hydrogen atoms.

The concept of keystone species is controversial among ecologists because most organisms are highly interdependent. if each of the trophic levels is dependant on all others how can we say one is most important

Individuals do not compete directly for resources, but are prey for the same predator

Which of the following is likely not involved in this example of ecological succession? a) the rotting remains of plants add to the fertility of the soil. b)the soil becomes so fertile that eel grass is replaced by other plant species. c) the roots from plants stabilize the sediment, keeping it in place. d) the concentration of salt becomes so high that all plant life is destroyed.