Ans: There are two primary types of nutrition in living organisms:
Autotrophic Nutrition:
Autotrophic organisms are capable of synthesizing their own organic molecules, primarily carbohydrates, from inorganic substances like carbon dioxide and water.
These organisms capture and convert energy from external sources, such as sunlight or inorganic chemicals, to fuel the synthesis of organic compounds.
Autotrophic nutrition is further divided into two types:
- Photoautotrophs: These organisms, like plants and some types of algae and bacteria, use sunlight (photosynthesis) to convert carbon dioxide and water into glucose and other organic molecules.
- Chemoautotrophs: Certain bacteria and archaea use chemical reactions involving inorganic compounds, such as hydrogen sulfide or ammonia, to produce organic molecules and generate energy.
Heterotrophic Nutrition:
Heterotrophic organisms are unable to synthesize their own organic molecules from inorganic sources and must obtain preformed organic compounds from other organisms.
They obtain nutrients by consuming other organisms or organic matter, breaking down complex molecules into simpler forms, and then using these simpler molecules for energy and growth.
Heterotrophic nutrition is further categorized into different types, depending on the source of food:
- Herbivores: Herbivores primarily feed on plants and plant-based materials. They obtain carbohydrates, proteins, and other nutrients from plant tissues.
- Carnivores: Carnivores primarily consume other animals. They obtain nutrients by eating the flesh or body parts of other animals, which are rich in proteins and fats.
- Omnivores: Omnivores have a varied diet, consuming both plant and animal materials. Humans are an example of omnivores.
- Detritivores: Detritivores feed on decaying organic matter, such as dead plants and animals. They help break down organic material into simpler substances, which can be further decomposed by bacteria and fungi.
Parasites: Parasites obtain nutrients from living hosts, often causing harm to the host organism. They include organisms like tapeworms, ticks, and certain bacteria.