Which of the following is an autotrophic mode of nutrition?

Explanation

The question is asking which of the following modes of nutrition is autotrophic. Autotrophic nutrition is the process by which organisms produce their own food using inorganic substances. The options given are chemosynthesis, saprophytism, parasitism, and symbiosis. Option A, chemosynthesis, is the correct answer because it is a form of autotrophic nutrition where organisms use energy from chemical reactions to produce their own food. This process occurs in deep-sea vents and other extreme environments where sunlight is not available. Option B, saprophytism, is a type of heterotrophic nutrition where organisms feed on dead or decaying organic matter. Option C, parasitism, is a type of heterotrophic nutrition where an organism feeds on another living organism, the host. Option D, symbiosis, is a type of relationship where two organisms live together in close association, but only one organism benefits. It is not a mode of nutrition. It is important to understand the different types of nutrition in biology as it helps us understand how organisms obtain their energy and nutrients for survival. Autotrophic organisms are important in the food chain as they form the basis of the food web. To learn more about this, please read the relevant sections of the recommended textbooks.