Animal feed includes vitamins and proteins mainly.

$(i)$ Name the three varieties of pesticides used.
$(ii)$ Write the problems related to the excess use of pesticides.

Which one is an oil-yielding plant among the following?

$(a)$ Distinguish between macronutrients and micronutrients on the basis of $(i)$ their functions and $(ii)$ amount required by plants. $(b)$ Classify the following elements as macro or micronutrients in plants: $(i)$ Nitrogen,$(ii)$ Zinc,$(iii)$ Copper,$(iv)$ Potassium. $(c)$ In what way is the deficiency of these nutrients harmful to crops?

The major groups of activities for improving crop yields can be classified as:

During class,Ravi's teacher was teaching about Thomson's model of an atom,stating that an atom is electrically neutral,i.e.,it contains equal positive and negative charges,and that an atom consists of a sphere of positive charge in which electrons are embedded like plums in a pudding. Ravi wondered how his teacher related Thomson's model of an atom to a plum pudding,and he imagined that just as dry fruits are embedded in a Christmas pudding,electrons are embedded in a sphere of positive charge.
$(a)$ According to you,what kind of qualities does Ravi possess?
$(b)$ What are the limitations of Thomson's model?