Autotrophy And Heterotrophy - SS1 Biology Lesson Note

Autotrophy and heterotrophy are two distinct modes of nutrition observed in organisms.

Autotrophy: Autotrophs are organisms that can synthesize their own organic compounds using inorganic substances as a source of energy. They are primary producers in the food chain and typically utilize photosynthesis or chemosynthesis to convert light energy or chemical energy respectively into organic molecules. Autotrophs include green plants, algae, and certain bacteria.

Photosynthetic autotrophs, such as plants and algae, capture sunlight through pigments like chlorophyll and use it to convert carbon dioxide and water into glucose and oxygen. This process, known as photosynthesis, is crucial to produce organic matter and the release of oxygen into the atmosphere.

Chemosynthetic autotrophs, found in deep-sea ecosystems or extreme environments, use chemical reactions to derive energy for the synthesis of organic molecules. They obtain energy from inorganic substances like hydrogen sulfide or methane instead of sunlight.

Heterotrophy: Heterotrophs are organisms that obtain their organic molecules and energy by consuming other organisms or their organic products. They are unable to produce organic compounds from inorganic sources and rely on the organic matter generated by autotrophs or other heterotrophs. Heterotrophs include animals, fungi, and many bacteria.

Heterotrophs can be further classified based on their feeding strategies:

1.     Herbivores: Herbivores consume plant material as their primary source of nutrition.

2.     Carnivores: Carnivores primarily feed on other animals.

3.     Omnivores: Omnivores have a mixed diet, consuming both plant and animal matter.

4.     Detritivores: Detritivores obtain their energy by feeding on dead organic matter or decaying material.

5.     Parasites: Parasites live in or on other organisms, known as hosts, and obtain nutrients at the expense of their host.

Heterotrophs rely on the organic compounds synthesized by autotrophs for their survival and energy requirements. They play a vital role in consuming and recycling organic matter, transferring energy through the food chain, and maintaining the balance of ecosystems.

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