Is coal dust a targeted or systemic toxicant? explain.

How many chromosomes are in a gold fish?

Whay is the following best defines climate

Why do leaves change color in the fall? green pigments break down and no longer mask the color of chlorophyll. chlorophyll breaks down and no longer masks the colors of other pigments. red- and yellow-colored pigments grow and mask green-colored chlorophyll. green-colored chlorophyll breaks down and turns red and yellow.