4. Bacillus thuringiensis (Bt) is a bacterium that contains a gene that results in the production of a natural pesticide that kills insects. Genetic engineers have successfully inserted this Bt gene into the DNA of some corn varieties, allowing the corn to produce its own pesticide.

What negative consequence could result from this technology?
A. Only corn that is resistant to the Bt gene will survive.
B. Individual insects that eat the genetically modified
corn will develop resistance to Bt.
C. The genetically modified crops will insert this Bt gene
into the DNA of humans that eat the corn.
D. Only Bt resistant insects will survive to reproduce,
eventually producing a population of entirely resistant
individuals.

To answer this question, we need to analyze the potential negative consequences of inserting the Bt gene into corn.

A. Only corn that is resistant to the Bt gene will survive.
To determine if this is a potential negative consequence, we need to understand the impact of corn being resistant to the Bt gene. If all corn becomes resistant to the Bt gene, it could lead to a decrease in the effectiveness of the natural pesticide, making it less useful for controlling insect populations. This could result in increased damage to the corn crops and potentially reduce yields. Thus, this is a possible negative consequence.

B. Individual insects that eat the genetically modified corn will develop resistance to Bt.
Insects that feed on genetically modified corn containing the Bt gene could potentially develop resistance to Bt. This could occur through natural selection, where insects with genetic variations that provide resistance to Bt are more likely to survive and reproduce, passing on their resistant genes to future generations. As a result, the effectiveness of the Bt pesticide on these insects could decrease over time. Therefore, this is another possible negative consequence.

C. The genetically modified crops will insert this Bt gene into the DNA of humans that eat the corn.
It is unlikely that the Bt gene would be inserted into the DNA of humans that consume genetically modified corn. The process of genetic modification involves inserting specific genes into the plant's DNA, and these genes are typically not incorporated into human DNA when consumed. Therefore, this is not a valid negative consequence.

D. Only Bt resistant insects will survive to reproduce, eventually producing a population of entirely resistant individuals.
This option is similar to option B, as it describes the potential development of resistance in insects that are exposed to the Bt gene. If insects that are resistant to Bt survive and reproduce, the population could become dominated by resistant individuals over time. This could reduce the effectiveness of the Bt pesticide and make it less efficient for controlling insect pests. Thus, this is also a possible negative consequence.

Based on the explanations above, the negative consequence that could result from inserting the Bt gene into corn is option D. Only Bt resistant insects will survive to reproduce, eventually producing a population of entirely resistant individuals.