In which kingdom is $Methylophilus$ $methylotrophus$ classified?

Some bacteria are not easily killed because of:

Which among the following are the smallest living cells,known without a definite cell wall,pathogenic to plants as well as animals and can survive without oxygen?

Select the mismatched pair from the following.

Which of the following is responsible for causing diseases in the cardiovascular system?

What type of nutrition is exhibited by organisms of the Kingdom Monera?