Originally Posted by awais274

2) Briefly describe the role of nitrogen , phosphorous and potassium in the growth of plants. What are negative impacts of fertilisers?

3) Why long exposure of human skin to the sunlight is dangerous? What are various natural protections in our body against the harmful radiations in the Sunlight? Is there any positive impact of radiations?

4) Describe briefly the difference between. Conductors, semiconductors and insulators?

5) Give a brief account of use of radiation in medical diagnosis. Why MRI is preferred over CT scan or X-RAY imaging?

6)a) Why DDT once labelled as a miracle is now being considered an Environmental tragedy?
b) A large variety of deodorants mask the original odour of our body . Which body part produces the unpleasant smell and how it is produced?

7) Why people have switched to vegetable oil for cookin instead of saturated fats? Which of these two contain higher level of LDL? Is it HDL or LDL which is harmful to human health and why?

8) What are natural sources of vitamin D and symptoms of its deficiency in humans?
Why an indiscriminate use of antibiotics may prove dangerous?

9) Define Radioactivity . How alpha , beta and gamma radiations are produced as a result of decay of an unstable nucleus differ in their effects on living beings?