Under ideal conditions, how do allele frequencies change over time?
a. the allele frequency reaches over time.
b. the allele eventually reach a 50/50 balance.
c. the frequency of the dominant allele increases over time.
d. the frequency of the recessive allele increases over time.

Option D, The frequency of the recessive allele increases over time.

Explanation:

A dominant allele is usually expressed in a gene even if it present in pair with a recessive allele (until unless it is a co dominant species). While a recessive trait is expressed only when both alleles in a pair are recessive.  

Let us see through an example

Suppose both the male and female mating flower species are heterozygous dominant species. Thus,  only the dominant trait is expressed however the parent flowers also carry recessive allele.  

Let the male  flower be of  blue (Bb)  color and the female flower is also blue (Bb)

If a cross is carried out the between these two adults flowers, the following offspring are produced

Bb X Bb

BB, Bb. Bb, bb

The allele pair bb will produce white color flower.  

Hence with increase in time the frequency of the recessive allele increases

what statement best describes the difference between the sympathetic and parasympathetic nervous systems?

the sympathetic nervous system prepares the body for intense physical activity and is often referred to as the fight-or-flight response. the parasympathetic nervous system has almost the exact opposite effect and relaxes the body and inhibits or slows many high energy functions.

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.