The first cell that was viewed by the light microscope was the oak bark.
I believe the correct answer is chromosome.
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Explanation:</h2>
We inherit 23 chromosomes from our mother and another 23 chromosome pairs from our father. You have to inherit a defective chromosome for you to get the mutation. This is what is called germ line mutation usually carried in the sperm or ovum. Of the 23 chromosomes, 22 are autosomal and 1 is chromosomal meaning of the 23 one of them is X and another one is . You get the Y from your father and the X from your mother.
Twelve pairs of ribs are attach to the second spinal region which is called the thoracic. Thoracic spine is kyphotic. Kyphotic means excessive curvature of the spine as it occurs in thoracic and also sacral regions. Thoracic spine is located in the chest area.The ribs are attach to the thoracic spine and protect the vital organs that is located thoracic spine region.
Environmental functions is the correct option. Hope it helped U. If it helped you please mark as brainliest