Oxygen gas (o2) is produced by plants and algae. what is the source
of oxygen atoms in these molecules?
a. water
b. glucose
c. carbon dioxide
d. atmospheric oxygen
e. atmospheric nitrogen

What are four key elements of the study of economics?

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.

The hematodinium parasite becomes less of a problem for the blue crab when the crab is very young. fishing is thriving in the region. the crab moves to less salty water. a significant percentage of the population is impacted.