Biotic (Living) Components

Biotic Components include the living things (crops and animals)

Classes of Biotic Components:

1. Autotrophism/Autotrophic.
2. Heterotrophism/Heterotrophic.

1. Autotrophism/Autotrophic:

Autotrophs are a group of organisms which can use sunlight or chemicals to manufacture their food from organic substances during the process of photosynthesisPhotosynthesis is the process by which green plants, and some algae and bacteria, convert the energy of sunlight into chemical energy. This energy is then used to synthesize carbohydrates such as... More.

The type of feeding employed by plants is called autotrophicAn autotroph is an organism that can produce its own food using light, water, carbon dioxide, or other chemicals. It feeds itself, without the assistance of any other organisms. The word... More nutrition/autotrophism.

Autotrophic nutrition can be classified into two categories:

i. Photosynthesis
ii. Chemosynthesis

(i) Photosynthesis:

This is the process by which green plants use the energyEnergy is the ability to do work. Energy exists in several forms such as heat, kinetic or mechanical energy, light, potential energy, and electrical energy. Units of Energy: The SI unit... More of light to convert carbon dioxide and water, into simple sugar glucose, using sunlight as a source of energy and chlorophyll for trapping the light energy.

The process by which these plants manufacture their food can be represented as follows:

\( \scriptsize \underset{Carbon dioxide}{6CO_2} \: + \: \underset{Water}{6H_2O} \: \underset{Chlorophyll}{\rightarrow}\: \underset{Carbohydrate}{C_{6}H_{12}O_{6}} \: + \: \underset{Oxygen}{6O_2} \)

(ii) Chemosynthesis:

This is the process in which some types of microorganismsMicrobes are organisms that are too small to be seen without using a microscope. They include organisms like bacteria, archaea, and single-cell eukaryotes (organisms whose cells have a nucleus e.g. amoeba... More use energy from chemical reactions to produce organic compounds as food for themselves.

2. Heterotrophic/Heterotrophism:

Organisms, mainly farm animals, which cannot manufacture their own food but depend directly or indirectly on plants for their food, are called consumers.

Farm animals that feed directly on green plants (producers) are called herbivores or primary consumers.

Examples of Herbivores:

Cattle, Sheep and Goat.

Animals or organisms that feed on the primary consumers are called carnivores or secondary consumers.

Animals that feed on secondary consumers are called tertiary consumers.

Heterotrophs include all farm animals, fungi and some bacteria.

Categories of Heterotrophism (Heterotrophic Nutrition)

a. Holozoic Nutrition.
b. Symbiotic Nutrition.
c. Parasitic Nutrition.
d. Saprophytic Nutrition.

a. Holozoic Nutrition:

This type of nutrition Involves feeding on solid organic materials, obtained from the bodies of other organisms.

They can be classified into;

i. Carnivores: Those animals that feed on flesh (Cat, Dog and Lion)
ii. Herbivores: These are plant eaters (Goats, Sheep and Cattle)
iii. Omnivores: These are animals that feed on both plants and animals (Pigs, Rabbits)

b. Symbiotic Nutrition:

In this type of nutrition, the organisms mutually benefit from one another for survival.

Examples of Symbiotic Nutrition:

• The association between bacteria in the gut and stomach of ruminantRuminant animals are animals that have a stomach with four compartments: the rumen, reticulum, omasum, and abomasum. They include animals such as cattle, sheep, goats, deer, and antelope. Ruminants swallow the... More animals, which aids in food digestionDigestion is the breakdown of large insoluble food compounds into small water-soluble components so that they can be absorbed into the blood plasma. In certain organisms, these smaller substances are absorbed... More.
• Cattle and tick birds.
• Fungus and roots of higher plants.
• Algae and fungi (lichen)

c. Parasitic:

This involves feeding on the organic compound present in the body of another living organism (the host). The organism, called the parasite, lives in, or on, another organism called the host, from where nourishment is derived. In this case, the parasite is gaining and the host is losing.

Examples of Common Parasites:

• Mistletoe on cocoa.
• Tapeworms on pigs and sheep.
• Ticks on dogs.
• Lice on poultry birds.

d. Saprophytic:

This involves feeding on soluble organic compounds, obtained from the remains of dead animals and plants.

Common examples of Saprophytes are certain bacteria and fungi.