The most abundant prokaryotes helpful to humans in making curd from milk and in production of antibiotics are the ones categorised as
- cyanobacteria
- archaebacteria
- chemosynthetic autotrophs
- heterotrophic bacteria
Answer
(4) heterotrophic bacteria
Solution
As per NCERT, heterotrophic bacteria are the most abundant in nature. The majority are important decomposers.
⇒ Many of them are helpful to humans, e.g. in making curd from milk, production of antibiotics and fixing nitrogen in legume roots.
Answer: (4)