Question

A challenge in agriculture is growing crops without also growing unwanted plants such as weeds. To prevent weeds from growing in the same area as soybean crops, scientists have developed a certain herbicide that destroys a protein found in all plants. Scientists also created a genetically modified soybean strain that is resistant to the herbicide by injecting bacterial DNA into the nuclei of the cells in the soybean seeds. When the herbicide is sprayed on a field where genetically modified soybean plants are grown, all of the weeds growing on the field die, but the soybean plants live.

Which statement best explains why the soybean plants are resistant to the herbicide?
A.
The scientists changed the structure of the soybean plants, which allowed the soybean plants to survive without proteins.
B.
The scientists altered the genetic makeup of the soybean plants, which changed the types of proteins the soybean plants produced.
C.
The scientists replaced some DNA in the soybean plants, which changed some parts of the soybean plants into bacteria.
D.
The scientists modified the proteins that are found in soybean plants, which changed how the soybean plants react to herbicides.

Answer 1

B

Injecting bacterial DNA changed the soybean plants' genes so they produce different (or altered) proteins—one that the herbicide no longer destroys. A is wrong (plants still need proteins), C is wrong (they didn't turn into bacteria), and D is less accurate because the proteins were changed by altering the DNA, not by directly modifying existing proteins.