What happen to plants that are kept in the dark

Explain how sequences of amino acids in proteins can be used to reveal relationships among organisms.

Ivan is looking at a cross section of a stem taken from a vascular plant. he sees two different types of vascular tissue: the xylem, which is closer to the center of the stem, and the phloem, located around the xylem, closer to the outside of the stem. how do these two structures work together in a living plant?

If a checkpoint detects damaged dna, the checkpoint may