EVS 2nd Unit - Ecosystem

Question 1

What is Environment?

Answer 1

It is the natural component in which biotic and abiotic factors interact among themselves and with each other.
These interactions shape the habitat and ecosystem of an organism.
All organisms are dependent on the environment to carry out their natural life processes and meet their physical requirements.

Question 2

What is Biosphere?

Answer 2

Biosphere is the biological component (supporting life) of earth which includes lithosphere, atmosphere and hydrosphere.
Biosphere absent at extremes of the North and South poles, the highest mountains and the deepest oceans, since existing hostile conditions there do not support life.

Question 3

What is habitat?

Answer 3

Habitat is the physical environment in which an organism lives (Address of an organism).
Many habitats make up the environment.
A single habitat maybe common for more than one organism which have similar requirements.
For eg: A single aquatic habitat may support a fish, frog, crab, phytoplankton and many others.

Question 4

What is an ecosystem?

Answer 4

An ecosystem can be visualized as a functional unit of nature, where living organisms (producers, consumers and decomposers) interact themselves and with the surrounding physical environment.

• Here biotic and abiotic components are linked together through nutrient cycles and energy flows.
• Everything that lives in an ecosystem is dependent on the other species and elements that are also part of that ecological community.
• If one part of an ecosystem is damaged or disappears, it has an impact on everything else.

Question 5

Types of ecosystems?

Answer 5

• Terrestrial
• Aquatic
  - Fresh water ecosystems
  - Marine ecosystems
• Humanmade

Question 6

What is ecology?

Answer 6

Ecology is the study of interactions between organisms, and the surroundings occurring within an ecosystem or environment.

Question 7

Components of an ecosystem?

Answer 7

Biotic (living) and abiotic (non living) components.

Abiotic includes inorganic and non living parts; light, rainfall, temperature, atmosphere, organic and inorganic compounds.
Biotic includes ; producers, consumers, decomposers.

Question 8

Primary consumers or autotrophs?

Answer 8

They are self nourishing.
Primary consumers are green plants, certain bacteria and algae that carry out photosynthesis.
In the aquatic ecosystem, microscopic algae (plankton) are the primary producers.

Question 9

Consumers?

Answer 9

Also known as Heterotrophs or phagotrophs
Other nourishing.
Incapable of producing their own food.
They depend on organic food derived from plants, animals or both.
Consumers can be divided into two broad groups namely micro and macro consumers.

Question 10

Macro consumers?

Answer 10

Herbivores are primary consumers which feed mainly on plants. Eg: Sheep, rabbit etc.
Secondary consumers feed on primary consumers.
Eg: Wolves, dogs, snakes etc.
Carnivores which feed on both primary and secondary consumers are called tertiary consumers. Eg: lion (can eat wolves), snake etc.
Omnivores are organisms which consume both plants and animals. Eg: man, bear, pig etc.

Question 11

Micro consumers or saprotrophs?

Answer 11

Also known as decomposers or osmotrophs.
They are bacteria and fungi which obtain energy and nutrients from dead organic substances (detritus).
Earthworm and certain soil organisms are detritus feeders and help in the decomposition of organic matter and are called detrevores.