Tax matter

I have some query regarding taxation:

1.) Why does the interest income on savings bank and Recurring Deposit have to be individually filed whereas for Fixed Deposit tax is deducted at source?

2.)  Suppose a  person comes under non taxable category and now due to circumstances like husband/wifes death, recieves a lumpsum payment of 10 lacks or more into there account in insurance claim settlement will he/she become taxable based on the lumpsum amount recieved for that financial year?

If anyone can throw light in this matter it will be highly appreciated