Select six operations performed or directed by the nucleus:

1 cell reproduction

2 invasion guard

3 instructions

4 coded information

5 power plant

6 chromosomes

7 exact placement of varieties of cells

8 control center

9 waste disposal

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