After combing his hair,Sameer kept the comb on the table where some pieces of paper were lying. He observed that the plastic comb attracted small pieces of paper. He was surprised to see this and asked his teacher about it. His teacher explained to Sameer that matter contains charged particles and that an electrically charged object can attract an uncharged object. Specifically,upon rubbing with dry hair,a comb acquires an electric charge,which then attracts the pieces of paper.
$(a)$ Give any other practical application of this.
$(b)$ What kind of qualities are shown by Sameer?

Which one of the following nutrients is not available in fertilizers?

India is a country where three-fourths of the population is engaged in agriculture. Even though the financial conditions of some farmers allow them to adopt higher-level farming practices and improved agricultural technology,they are hesitant to use $HYV$ seeds with traits such as resistance to diseases and pests,or qualities that would result in higher yields.
$(a)$ What is meant by genetically modified crops?
$(b)$ What are the desired agronomic characters for fodder and cereal crops?
$(c)$ In your opinion,what should be done so that modern agricultural technology is adopted by most farmers?

Distinguish between intercropping and mixed cropping. List any two advantages of intercropping over mixed cropping.

The housing, nutritional and environmental requirements of broilers are somewhat different from those of egg layers.

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