The earliest primates evolved long after the dinosaurs went extinct. A.
True
B.
False

Acceleration is a direct result of a.) balanced forces b.) unbalanced forces c.) gravity d.) velocity

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?

Why has two different alleles for the same trait?