Charles Metri, age 10, of Staten Island, New York, for his question:

Does his shell grow with the turtle?

The turtle's shell must last through his whole life    for he cannot grow a replacement. A tiny shell is there, right on his back, when a baby turtle hatches. As he grows bigger, his shell grows with him. If you have a pet turtle, it is a good idea to study his shell through a magnifying glass. It seems to be made of shell shaped sections, all fused together to form a pair of solid shields    one on top and one below. On most turtles, you can see fine ridges and grooves curving around the shell sections. These are growth rings. They can tell you his age because each year he adds a new ridge around the edge of each section.

This explains why Andy is always saying not to put paint on turtle shells. Around the sections that make up the shell, there are very special cells, cells that add the extra material as the growing turtle needs more room. Tacky paint and other chemicals injure these cells. Next year, some of them fail to add a new ridge. The turtle shell grows twisted and deformed    and this may be disastrous for the turtle.