<span>Since a gene that acts as a pesticide is inserted into a corn, that corn is now safe from insects. This will happen because the corn will probably synthesise protein according to that inserted DNA sequence and that protein will serve as a repellent to the insects. However, the Red Queen's hypothesis in evolution explains that organisms must constantly adapt and evolve in order to survive. This refers to insects. If they could not eat genetically modified corn, they would extinct. So, they must adapt or evolve in order to survive. So, it is expected that insects that are resistant to this specific pesticide would develop through the time.</span>
The controlled experiments are performed by the scientists, when they want to study the changes in the sample on changing a single variable. So, the correct answer is option (b).
In case, all variables are kept same, no changes would be observed in the experiment sample. A controlled experiment can be performed on living thing as well as non living. But, controlled experiment cannot be performed on the things which are influenced by a lot of variables, as they cannot create realistic results. So, the option (a), (c), and (d) are incorrect.
Many scientists never wear a lab coat at all. Some work in fields that don't require lab work and do their work behind a computer. Some use their science degrees to teach or write about science. Some work as consultants for companies, or as editors for scientific journals.