I think it be D.But if that ever happen I'm sure that the scientists will find away to stop it
Unoxygenated blood from veins enters the right atrium then it goes down to the right ventricle then out through the pulmonary artery to the lungs where it becomes oxygenated blood which then enters the heart through the pulmonary veins and it goes to the left atrium and then is pumped down to the left ventricle and out through the aorta to the arteries where it travels to different organs and becomes deoxygenated and then the cycle repeats itself.
The name you're looking for is Gregor Mendel. He first saw it in his experiments with peas that had different traits (leaves, stem, colour, texture) etc.
Hope it helps!
Answer:
The wildlife sanctuaries are established to protect the endangered species. A few sanctuaries take in injured and abandoned animals and rehabilitate them to health before releasing them in the forest. Wildlife sanctuaries preserve the endangered species and protect them from humans and predators.
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good luck