A atom is Biotic because all things living or nonliving are made up of matter, and all matter is composed of tiny particles called atoms. And atoms combine together to form molecules.
<em><u>valves:</u></em><em><u /></em><u /> veins have valves arteries do not have...
<em><u>lumen:</u></em><em><u /></em><u /> in arteries it is small while in veins it is large...
<em><u>walls:</u></em><em><u /></em><u /> in arteries walls are thick ..in veins walls are thin...
<em><u>blood:</u></em><em><u /></em><u /> veins have deoxygenated blood (except pulmonary vein) .. while arteries have oxygenated blood...(except pulmonary artery)...
100% brown Because dominate (B ) over powers recessive(b)
