Which group of prokaryotes is most abundant and beneficial to humans in the process of making curd from milk and the production of antibiotics?

Heterotrophic bacteria

The answer is (d) Heterotrophic bacteria.

Heterotrophic bacteria are the most abundant and beneficial to humans in the process of making curd from milk and the production of antibiotics. They are used in the production of curd from milk because they produce lactic acid, which sours the milk and coagulates the proteins. They are also used in the production of antibiotics because they produce a variety of antibiotics, such as streptomycin.

Cyanobacteria are photosynthetic bacteria that produce oxygen. They are not used in the production of curd or antibiotics.

Archaebacteria are a group of bacteria that live in extreme environments, such as hot springs and acidic lakes. They are not used in the production of curd or antibiotics.

Chemosynthetic autotrophs are bacteria that obtain energy from the oxidation of inorganic compounds. They are not used in the production of curd or antibiotics.