Surface currents, like the gulf stream,

a. river water that flows from land to the ocean
b. winds that flow over the surface of the ocean
c. water that moves at the oceans surface
d. air that flows over the surface of land

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?

Approximately what wavelength of light is best absorbed by chlorophyll a

Cells control gene expression at which steps