DDT was once considered a "silver bullet" that would permanently eradicate insect pests. Instead, DDT is largely useless against many insects because they are resistant. Propose a hypothesis as to why these organisms have become resistant to the chemical.

None of the individual insects should have possessed genomes that made them resistant to DDT.

Explanation:

Pesticides such as DDT have been considered one of the best way to kill insects in the past. But with time, farmers have observed that this is not an authentic method. This is because the insects can gain resistance to the pests if they are exposed to the pesticide again and again. Even they could transmit these resistant genes in their offsprings. Hence, DDT will become useless against insects over time.  

b

explanation:

4.) metal

"-the movement of carbon from the nonliving environment into living things and back to the environment

-carbon is the essential component of proteins, fats, and carbohydrates (which make up all organisms)

-carbon exists in air, water, and living organisms

-producers convert carbon dioxide in the atmosphere into carbohydrates during photosynthesis

-bacteria in the atmosphere cycles through the system in filtration units

-in cellular respiration, carbon is released back into the atmosphere as carbon dioxide

-some carbon is stored in limestone (forming one of the largest "carbon sinks" on earth)

-largest carbon reservoir on earth= limestone

-carbon stored in the bodies of organisms as fat, oils, or other molecules may be released into the soil or air when the organism dies

-this may form deposits of coal, oil, or natural gas (fossil fuels, which increased the atmospheric carbon dioxide)

-fossil fuels store carbon left over from bodies of organisms that died millions of years ago

-they are located in the surface of earth, deep within the earth and beneath the ocean floor."