Question

The most abundant prokaryotes helpful to humans in making curd from milk and in production of antibiotics are the ones categorised as

• A. Cyanobacteria
• B. Archaebacteria
• C. Chemosynthetic autotrophs
• D. Heterotrophic bacteria

Answer 1

The Correct Option is D

The question asks us to identify the most abundant prokaryotes that are beneficial to humans in processes such as making curd from milk and producing antibiotics. The options provided are various categories of bacteria or bacteria-like organisms.

1. Cyanobacteria: These are photosynthetic bacteria, commonly known as blue-green algae, which primarily perform photosynthesis. They are not involved in the process of curd formation or antibiotic production.
2. Archaebacteria: These are ancient bacteria adapted to extreme environments like hot springs and salt lakes. Archaebacteria are not typically used in curd production or antibiotic generation.
3. Chemosynthetic autotrophs: These bacteria obtain energy by oxidizing inorganic substances. They are not related to curd formation or antibiotic production.
4. Heterotrophic bacteria: These bacteria derive their nutrients from organic carbon sources. They include lactic acid bacteria (such as Lactobacillus) responsible for curdling milk, and other bacteria like Streptomyces which are known for producing antibiotics.

The correct answer here is heterotrophic bacteria, as they perform fermentation to produce yogurt (curd), and certain heterotrophs are utilized in antibiotic production.

In conclusion, heterotrophic bacteria play a crucial role in these processes, making them the right choice among the given options.