If the rice already had the genes that could make vitamin a, why did scientists use genes from other organisms?
a. the rice genes didn't make the right type of vitamin a.
b. it's easier to introduce genes from one species into another than from just one species.
c. scientists could have just "turned on" the rice genes, but they wouldn't have learned anything from that process.
d. it's easy to extract genes from bacteria.
e. the scientists didn't know how to "turn on" the genes in the rice.

A. The rice genes didn't make the right type of vitamin A.

Explanation:

Regular white rice does not have the gene to produce beta carotene. The human body converts the beta carotene into vitamin A.

To increase the nutritional value of rice, the gene for beta carotene from daffodil flowers was inserted into the cells of endosperm of rice.

This allowed these cells of the genetically engineered rice varieties to produce beta carotene. Production of beta carotene imparted golden color to the rice grain and hence, the name.

not sure if this what   you'r looking for would be percent composition