The cambium produces xylem toward the center of a tree and phloem toward the outside. do you think it would make any difference if the positions of the xylem and phloem were reversed? why?

What links the two strands in a dna helix together in the middle? a. phosphate groups b. sugar rings bonded together c. proteins d. bases with hydrogen bonds

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.

When a person is exercising the body needs to deliver increased amounts of oxygen to the muscles which component of blood ensures that the muscles will receive it