4. how are gene and protein sequences used to classify organisms?

Genes code for proteins and each organism has different genes.

Explanation:

Sequences of genes are used to identify differences and similarities between organisms. So it can be used to identify related organisms, because they show differences between species.

DNA acts as set of instructions for building an organism, because it contains the genetic instructions to make for proteins. Genes are made of DNA and each one codes for a different protein. In that way, different types of organisms can all be differentiated through their genes.

This is because the translation of proteins from DNA is guided by a universal code. It means, the same codons codes for the same amino acid across all species.

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.