Which two of these characteristics are examples of endoskeletons? scales in fish bones in mammals calcium-rich plates in echinoderms appendages in arthropods

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.

Long-period comets come from the oort cloud particles in earth’s atmosphere material from the asteroid belt the kuiper belt

The first generation of offspring from the cross of two parents is called the a.f1 generation b.f2 generation c.short generation d.p generation