This document provides an overview of ecosystems and their components. It discusses biotic factors such as producers, consumers, and decomposers. Producers include photoautotrophs and chemoautotrophs that generate energy through photosynthesis or chemical reactions. Consumers are divided into herbivores, carnivores, and omnivores. Decomposers break down organic matter from dead producers and consumers. Abiotic factors that influence ecosystems such as water, sunlight, temperature, soil, and atmosphere are also examined in detail.

1. Department of Zoology
Comparative Account of
Evolution of Aortic Arches
Submitted By
Rohan Patidar

2. Synopsis
• Introduction
• Ecosystem
• Biotic factor
• Abiotic factor
• Refrence

3. Ecosystem
• The term ecosystem was coined by A.G Tansley, an English
botanist in 1935.
• Ecosystem is known as both structural and functional units of
the environment where both biotic and abiotic factors
interact with each other to form a complete ecosystem.
• Thus we can say that ecosystems are made up of two
components: they are biotic factors and abiotic factors and
both these factors are equally important to maintain stability
in the ecosystem.

4. Abiotic factor
• It is the non-living part of an environment.
• It includes all the physical and chemical aspects of an ecosystem
• These factors may be present in the atmosphere, hydrosphere, and
lithosphere
• For example, Rainfall contributes to tropical rainforest ecosystems,
sand in desert ecosystems and water, salinity, ocean currents,
pressure in the marine ecosystem.

5. • Water
• Sunlight
• Temperature
• Soil
• Atmosphere
• pH
• Air Humidity
• Wind
• Elevation
Abiotic factors include:

6. Water
• If there is no water, life on earth is not possible.
• Water is an essential abiotic factor. Not only plants but animals
even tiny micro-organisms also need water for their survival. In
the absence of water, plants will die, i.e producers will die. Even
the plants in the desert require some amount of water.
Sunlight
• Sunlight is the major source of energy.
• Plants require sunlight for the photosynthesis process. It is the
process by which plants make oxygen and food using
carbondioxide and water and make it available for the animals.

7. Temperature
• Temperature is an important abiotic factor in an ecosystem.
• With the variations in the temperature, variations occur in the
type of plants and animals. For eg: Yak lives in cold regions
where there is low temperature.
• Nature has adjusted the body like the presence of long furs
which make it possible to survive.
• The temperature determines the rate of the metabolic reactions.
It affects various enzyme-catalyzed reactions.

8. Soil
• Soil is an important abiotic factor. It is made up of rocks along
with the decomposed plants and animals.
• With the help of the roots, plants acquire the water and minerals
from the soil. Soil are also of various types, whose nature and
composition vary and have different functions.
• The water holding capacity is also determined by its composition.
• In the aquatic environment, depending upon the characteristics
of the sediment, it determines the type of the benthic animals

9. Biotic factors
Biotic factors include living things like plants,
animals, bacteria, etc. It is divided into three
main groups;
1. Producers
2. Consumers
3. Decomposers

10. Producers
• Producers are known as autotrophs.
• By the use of inorganic materials and energy, they prepare their
own food.
• It is considered the first life form. It is because, in the early days
of origin, there were no consumers to feed on.
There are two major classes of producers.
Photoautotrophs
Chemoautotrophs

11. Photoautotrophs
• They use sunlight as the source of energy and carbondioxide as
the source of carbon.
• They mostly use the pigment, chlorophyll for capturing the
photon from the sun.
• Similarly, there are also pigments like rhodopsin and carotenoids
which are found in some bacteria, algae, and phytoplankton. They
are used for photosynthesis.
• Later they produce essential things like sugar, protein, lipids, etc.
• Examples: Green plants, green algae, and some bacteria

12. • They use chemical agents like hydrogen, iron, and
sulfur as the source of energy.
• They are usually found in places where the plants
cannot grow.
• They are found at bottom of the ocean or in acidic hot
springs.
• They are also involved in nitrogen fixation.
• Example of Chemoautotrophs: Methanogens. They are
the microorganism which are capable of making the
methane gas.
Chemoautotrophs

13. Consumers
They are also known as heterotrophs.
They don’t prepare their own food by themselves as the producers.
It includes all the heterotrophs.
Herbivores: Animals like a cow, buffalo, the goat which depend
directly on plants for food. They are primary consumers.
Carnivores: Animals like lions, tigers, which are flesh-eating
animals. They depend on the herbivores for food. They are
secondary consumers.
Omnivores: Animals like dog, cat which eat depend on both the
plants and animals

14. Decomposers
They are also known as detritivores.
They use organic compounds as the source of energy from the producers and
consumers.
In an ecosystem, decomposers play a vital role, as the complex substances are
broken down into simpler forms.
Such a simpler form can be further utilized again by the other organisms. It
includes different soil bacteria, fungi, worms, and flies.
When the animals die they get decomposed because of decomposers. Even
plants, fruits start rotting, it’s because of decomposers.

15. Decomposers play the important role in metabolizing waste
products.
Example of decomposer: Mushroom
For example, Composting
In our daily life, different wastes are obtained from the kitchen.
The leftover foods, fruits, vegetables, etc.
They are collected separately and put in a pile.
After some time, it yields the fertilizer which is organic and of high
quality which can be used in the field.

16. Refrence
1. Clark : Elements of ecology,
2. Odom : Fundamentals of Ecology,
3. South Woods : Ecological methods,
4. Trivedi and Goel : Chemical and biological methods for water
pollution studies

17. Thank you