Q.Even though the use of pesticides increases the crop production, they adversely affect the living organisms. Explain the function and the adverse effects of the pesticides.

Step 1. Function. Pesticides are chemicals used to kill, or stop the growth of, unwanted organisms -- protecting the crop from pests, fungal disease and weed competition, which is why their use increases crop production. They are classified by target: insecticides (target insects), fungicides (target fungi) and herbicides/weed-killers (target unwanted plants).

Step 2. Adverse effects of insecticides. Insecticides like DDT, BHC and aldrin can stay in soil for a long period of time and are absorbed by it, contaminating root crops such as carrot and radish -- these are also non-biodegradable, so they persist and can enter the food chain.

Step 3. Adverse effects of fungicides. Organo-mercury compounds, the most common fungicide, dissociate in soil to produce mercury, which is highly toxic.

Step 4. Adverse effects of herbicides. Herbicides such as sodium chlorate and sodium arsenite are toxic to mammals. …

Cover both halves the question explicitly asks for -- function (why they're used, increasing yield) AND adverse effects (why they're still harmful) -- using the three nam …

• Answering only with adverse effects and forgetting to first explain the actual function/purpose of pesticides (raising crop production), which th …