Which statement best describes arteries? a) all carry oxygenated blood to the heart. b) all carry blood away from the heart. c) all contain valves to prevent the backflow of blood. d) only large arteries are lined with endothelium.

Which of these organisms have the greatest amount of cell specialized

Ablastocyst is a group of cells that forms after a human egg is fertilized. the blastocyst consists of two types of cells. some of these cells will become the placenta. what do the other cells develop into?

Chlorophyll is found in plant leaves and absorbs light from the sun to enable plants to perform photosynthesis. magnesium is an important component of chlorophyll. the concentration of magnesium ions is higher in the root-hair cells of plants than in the soil. which mechanism of ion uptake would best enable a plant to produce a steady supply of chlorophyll? osmosis diffusion passive transport active transport