One of there ansestors must have had blue eyes, or might have been a genetic mutation. But it's rare to find such a random mutation. But we must keep in mind that reproduction of cells and when DNA is copied it could have a mutation. But the likely explanation would be that one of there ansestors or grand parents had blue eyes until the trait that forms brown eyes became more common in the family tree.
The two atria are thin-walled chambers that receive blood from the veins. The two ventricles are thick-walled chambers that forcefully pump blood out of the heart. The right atrium receives deoxygenated blood from systemic veins; the left atrium receives oxygenated blood from the pulmonary veins.
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Answer:
The answer is Polyculture.
Explanation:
It is a form of agriculture where more than one types of crops and animals are grown at the same place ,imitating the diversity of the natural ecosystem.
This practice is very advantageous because it helps in pest, weeds and disease with minimal chemical input.
Answer:
your answer is Magnesium
Explanation:
Magnesium deficiency results in yellowing between the leaf veins, sometimes with reddish brown tints and early leaf fall. Not so stunted as major nutrient deficiencies. Older leaves turn yellow at edge, interveinal chlorosis causes green arrowhead shapes or marbling in the centre of the leaf (speckling in cereals).
Answer: Autonomic: Acting or occurring involuntarily, without conscious control. Central nervous system: The part of the peripheral nervous system that transmits signals from the central nervous system to skeletal muscles, and from receptors of external stimuli, thereby mediating sight, hearing, and touch.
Explanation: