How can a growing animal get calcium to make new bone tissue?

Blood, made up of red and white blood cells, work together to form

I’m doing some practice exam questions for biology, and i’m not sure how to do these 3 parts to the question.

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.