1. Based on the food chain relationships shown by the arrows in the food web diagram, rank the
concentration of toxic chemicals in each plant/animal listed.
Use the following scale: 1 = lowest concentration - 4 = highest concentration.
a. Aquatic plant
b. Large fish
c. Eagle
d. Crayfish

Some birds look for food near cattle and other livestock. the movement of the cattle churns up the ground, making insects available to the birds. the cattle appear to be unaffected by the presence of the birds. what kind of relationship exists between the birds and the cattle? o a. parasitism o b. commensalism o c. predation o d. mutualism

Which substance contains thylakoids? a) nadph b)atp c)stroma d)chloroplast

Match each symbol with its description.