Why should we understand how to use microscopes

The green colored pigment in chloroplasts is? a. nitrogen b. chlorophyll c. chlorophorm d. chlorofloromethane

Which of the following particles always has a positive charge? a. electronb. neutron c. proton d. ion

What is point source pollution of an aquatic ecosystem? a) pollution of freshwater sources b) pollution from many sources that combine into one c) pollution that occurs over a wide area; water that runs off from fields, parking lots, and other land surfaces d) pollution that can easily be identified with a single discharge source, such as an open pipe which drains into a body of water