Hemoglobin has tetrahedral structure containing four heme groups that surround a globin group.
Heme is ringlike organic compound also known as a porphyrin to which an iron atom is attached. There are four iron atoms that bind four oxygen atoms and transport them to tissues.
The neurons conduct impulses over relatively long distance in the body. This is facilitated by their long cytoplasmic extensions
Sexual reproduction results diversity
Yes, plants are absolutely alive. They may not be conscious, sentiment beings, but they still perform cellular respiration, make waste products, and generate biomass (get bigger).
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