What are chemoautotrophs?

Name the nitrifying bacteria of the soil. Why are they called chemoautotrophs?

Following are the two statements regarding the origin life (a) The earliest organisms that appeared on the earth were non green and presumably anaerobes. (b) The first autotrophic organisms were the chemoautotrophic that never released oxygen.Of the above Statements which one of the following options is correct?

What are histones? What are their functions?

What are radio-isotopes? What are their applications?

What is biogas? What are its components ? What is the calorific value of biogas?