Answer:
Phenotypic plasticity
Explanation:
Humans have evolved over thousands of years to adapt to various environmental changes. For example, when we are in an environment that requires certain level of adaptation our off spring often formalizes epigenetic traits that lows them to overcome small changes in the environment. Over time certain genes that are turned on may remain on and eventually the ones that are off remains off. This give rise to some genes that "don't work" after millions of years of such evolution we end up with a complex genome with more DNA than "working genes".
answer:
by having a high genetic level of melanin in your skin, you're skin is more protected from the ultra violet sun rays. Darker skinned races have more melanin present, these races originate from hot countries where sunlight is often present; the production of melanin in their skin allows them to reflect and inhibits they're skin from becoming extremely damaged. Light skinned races don't have a large amount of melanin due to they're native countries lacking sunlight. This is an evolutionary adaptation of the human race.
Answer:
The left side of the heart receives oxygenated blood from the pulmonary vein and pumps it into the aorta, while the right side of the heart receives deoxygenated blood from the vena cava and pumps it into the pulmonary vein. The pulmonary vein and aorta also have valves connecting them to their respective ventricle.
Explanation:
<span>It is composed of water and other soluble ions. About 80% of the cytoplasm is water. It also contains dissolved carbohydrates, proteins and fats.
</span><span>It is a very good conductor of electricity.</span>
