How could modern day humans evolve into two different species? Come up with a future scenario and explain why it
would result in two different species of humans.

the correct answer is - d. china has a large and growing population.

the fact that china has a large (the biggest) population, and it is still growing, doesn't hinder the agriculture production in the country. in fact, it can for increased production in the agriculture, since there's more labor force, as well the sheer mass of people produces lots of scientists that come up with new inventions as to how to improve this sector. nice example is the inner mongolia region in china, in general dominated by the gobi desert, but few scientist came up with a nice idea as to how to make the region productive by using plants that are very resistant to droughts, so lots of people have been employed, and the region is becoming greener and greener each year, and the production of food in this region is also increasing.

sex cells are usually half's then they find another half and make a fertilize egg

you should wear a lead protective shield when having teeth x-rays

hope i

-lavira : )

not sure if this is what you'r looking for prokaryotes have organelles hope this out at least.