<span>geographic isolation.....</span>
This can happen because you have recessive and dominant characteristics passed down. So you can get a totally different chromosome that doesn't come from your parents because your grandparents may have had it or great grand parents, the line keeps going .
<span>Gregor Mendel conducted hybridization experiments on around 29,000 pea plants. Peas were an ideal choice for Mendel to use because they had easily observable traits there were 7 of which he could manipulate them.</span> He studied pea plants <span>because the are self pollinating , they grow fast , and they have many traits.</span>
The answer is a compound leaf!! Hope this helps ;)
The answer is D,Nucleus I think