Marfan syndrome is a dominant trait. a cross between a homozygous dominant and a heterozygote would produce what phenotypic ratio

The correct answer is- 4:0

Explanation:

Marfan syndrome is a genetic problem which affects the connective tissue in the body. The trait for this disease is autosomal dominant which means even one abnormal copy of this gene in the offspring or individual is sufficient to cause this syndrome.

Let S is the allele that is dominant for this syndrome and s is recessive. So if a cross between homozygous dominant(SS) and heterozygous individual (Ss) occurs than all the offspring would have this syndrome.  

                                   S      s

                              S  SS   Ss

                              S  SS   Ss

Therefore all 4 offspring would have at least one dominant allele which is sufficient to cause this syndrome. So the phenotype ratio would be 4:0.

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.