<span>Gene experssion are influenced by enviroment. the best example is skin color in case of human for e.g if person with fair color or white complexion goes to africa or any part where sun exposure is more his or her color gets dark .the darking of skin is due to melanin production. see here person is same only difference is in enviromental condition due to which gene which are responsible for the production of melanin are produced.
I hope u understood it</span>
Yes, because there is only so much weight it can hold.
"Eukaryote" roughly translates as "truly nucleated" and refers to organisms with a membrane-bound nucleus.
Such membrane-bound organelles are thought to have arisen via the invagination of the cell's own plasma membrane.
Other organelles such as the mitochondria and the chloroplast are believed to have once existed as separate organisms, but which were engulfed by other cells, forming a symbiotic relationship.