Blood flows in the cardiovascular system . . . (choose all correct)

because there is no friction

due to contraction of the heart

down a pressure gradient from aorta to capillaries

down a pressure gradient from capillaries to vena cava

Adrought killed all the plants in an agricultural farmland. gradually, due to wind and some birds for. nearby areas, new plants started sprouting l. what stage of succession was taking place in the farmland? a) competition b) nudation c) ecesis d) reaction e) migration

When fossil fuels are burned, carbon dioxide is released. how does this gas impact the environment?

What process occurs during cellular development as the cell changes into a specific type of cell with specialized functions? a. binary fission b. fusion c. differentiation d. meiosis