What fluid, with a very high osmolarity, was used in part 2 of the paper chromatography experiment? why is this important? why is it essential to keep it cool?

The fluid which has very high osmolarity used in the experiment was Sucrose solution.

This fluid is important because it regulates the natural reaction of the leaves and also prevents interference from outside sources.

It was essential to keep it cool because cold temperature helps inhibit the rate of photosynthesis so it gives protection to degradation of proteins.

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.