Down syndrome : nondisjunction ::

What was the land like over 500 million years ago? what was under the sea?

How does the diagram explain ocean currents? earth tilt 23.5 degreesquestion 1 options: earth's tilt causes uneven heating of earth which causes currents. earth's tilt causes the ocean to move because of gravity. earth's tilt and its rotation cause currents. earth's tilt causes uneven distribution of salt which causes currents.

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?