The term "ecosystem" is derived from the Greek word "Oikos" meaning.
- Body weight
- Food
- House
- Size
Answer
House
Reason — The term "ecosystem" is derived from the Greek word "Oikos" which means a "house", a dwelling place with the inhabitants living together and interacting with each other and also with their physical environment in some definite ways.
Rat in any food chain would occupy the position of
- Tertiary consumer
- Secondary consumer
- Primary consumer
- Producer
Answer
Primary Consumer
Reason — Rat is the primary consumer in the food chain. Rat is eaten by snake which is a secondary consumer of the food chain or ecosystem.
Evergreen broad-leaved trees are characteristic of
- Tropical rain forests
- Temperate deciduous forests
- Coniferous forests
- All of the above types of forests.
Answer
Tropical rain forests
Reason — These forests grow in regions where year-round rainfall is high and steady and frost is rare. Evergreen trees have broad leaves to permit transpiration of surplus moisture.
The number of steps in a food chain can never be more than
- Four
- Five
- Six
- Seven
Answer
Six
Reason — The number of steps in different food chains may vary from 2 to 5 and very rarely these can be 6 but never 7.
Sameer while studying the topic of 'Interdependence between organisms' found that some organisms live together and benefit each other. Which of the following is a suitable example of such a relationship ?
- Algae
- Bacteria
- Fungi
- Lichen
Answer
Lichen
Reason — Lichens provide a good example of symbiosis in which a fungus and a photosynthetic alga live in a symbiotic relationship.
Predators are the animals who chase other animals, kill them and feed on their flesh. Which of the following statements supports this given explanation?
P. They are carnivores.
Q. They belong to trophic level-2 of the food chain.
R. They are also considered as decomposers.
- Only P
- Only Q and R
- Only P and Q
- Only P and R
Answer
Only P
Reason — Predators are carnivores (flesh-eating animals). They belong tp Trophic level-3 of the food chain.
Latika has prepared a food web which is a network of interconnected food chains. Which of the following are involved in a food web?
1. Producers
2. Sunlight
3. Herbivores
4. Secondary consumers
- Only 2 and 3
- Only 1, 2 and 3
- Only 1, 3 and 4
- Only 1 and 3
Answer
Only 1, 3 and 4
Reason — Producers, Herbivores, and Secondary consumers are components that are part of a food web.
Assertion (A): All plant eating animals are considered as primary producers.
Reason (R): Producers are the first step of the food chain which can supply food to the next trophic level.
- Both A and R are true.
- Both A and R are false.
- A is true and R is false.
- A is false and R is true.
Answer
A is false and R is true.
Explanation — All plant eating animals are considered as primary consumers. Producers supply food to the next trophic level, i.e. plant eating animals or herbivores.
Assertion (A): An ecosystem consists of two categories of components Biotic and Abiotic which are interdependent on each other.
Reason (R): Biotic components are dependent on abiotic components but never on other biotic components.
- Both A and R are true.
- Both A and R are false.
- A is true and R is false.
- A is false and R is true.
Answer
A is true and R is false.
Explanation — Biotic components are dependent on both abiotic components and on other biotic components as well.
Assertion (A): Symbiosis, parasitism and predation are the categories of interdependence between organisms, which are the ways of transferring energy.
Reason (R): The transfer of energy from one trophic level to the other always occurs through the food chain.
- Both A and R are true.
- Both A and R are false.
- A is true and R is false.
- A is false and R is true.
Answer
A is true and R is false.
Explanation — Many organisms get their energy through complex food webs, which include multiple interconnected food chains. Hence, the transfer of energy from one trophic level to the other does not always occur through the food chain, but food web.
Assertion (A): Flora and fauna of a forest are always the same throughout the world.
Reason (R): Usually, forest contains very big trees and animals. So, whatever climatic conditions are present, plants and animals remain the same.
- Both A and R are true.
- Both A and R are false.
- A is true and R is false.
- A is false and R is true.
Answer
Both A and R are false.
Explanation — Flora and fauna of a forest can never be the same throughout the world. Also, the climatic conditions significantly affect the type of plants and animals that can survive in a forest. They do not remain the same everywhere.
Assertion (A): Scavengers are considered as cleaners of the earth as they feed on dead animal and plant materials remains.
Reason (R): Scavengers consume the remains left by detritivores and decomposers.
- Both A and R are true.
- Both A and R are false.
- A is true and R is false.
- A is false and R is true.
Answer
A is true and R is false.
Explanation — Detritivores and decomposers consume the remains left behind by the scavengers.
Fill in the blanks :
Lichens are the good example of ............... association.
Two intermediate hosts of liver fluke are ............... and ............... .
Evergreen trees are common flora of ............... forests.
............... will always be trophic level-1 in a food chain.
............... sanctuary is found in West Bengal which is famous for rhinoceros.
Answer
Lichens are the good example of symbiotic association.
Two intermediate hosts of liver fluke are snail and fish .
Evergreen trees are common flora of tropical forests.
Plants will always be trophic level-1 in a food chain.
Jaladpara sanctuary is found in West Bengal which is famous for rhinoceros.
Mention if the following statements are true (T) or false (F):
Snakes are primary consumers.
Some humans are strictly primary consumers while others are secondary or tertiary consumers as well.
No ecosystem can survive without light.
Answer
False
Reason — Snakes are tertiary consumers.True
True
Match the items in Column A with those in Column B.
| Column I | Column II. |
|---|---|
| Grass | Carnivore |
| Deer | Decomposers |
| Cobra | Primary consumer |
| Vulture | Autotroph |
| Microbes | Scavenger |
Answer
| Column I | Column II. |
|---|---|
| Grass | Autotroph |
| Deer | Primary consumer |
| Cobra | Carnivore |
| Vulture | Scavenger |
| Microbes | Decomposers |
Rewrite the following in their correct sequence in a food chain:
(a) Snake → Grasshopper → Grass → Frog
(b) Grass → Tiger → Deer
(c) Snake → Peacock → Rat → Wheat
(d) Lizard → Grass → Crow →Grasshopper
(e) Goat → Man → Maize
Answer
(a) Grass → Grasshopper → Frog → Snake
(b) Grass → Deer → Tiger
(c) Wheat → Rat → Snake → Peacock
(d) Grass → Grasshopper → Lizard → Crow
(e) Maize → Goat → Man
Choose the odd one out and write the category of the remaining terms :
(a) Bacteria, Fungi, Vulture, Protists
(b) Air, Water, Plants, Temperature
(c) Rice, Grass, Grasshopper, Maize
(d) Deer, Rabbits, Tigers, Rats
(e) Plasmodium, Tiger, Liver fluke, Tapeworm
Answer
(a) Odd term: Vulture
Category: Microorganisms
(b) Odd term: Plants
Category: Abiotic factors
(c) Odd term: Grasshopper
Category: Autotrophs
(d) Odd term: Tigers
Category: Herbivores
(e) Odd term: Tiger
Category: Parasites
Given below is a box containing some words/phrases. Out of these, ten can be used to make five suitable pairs. Choose and make 5 such pairs.
| Oikos, Food, Grasshopper, Troph, Tertiary consumer, Producers, House, Green plants, Evergreen trees, Gir forests, Ecosystem, Man, Lion |
|---|
Answer
- Oikos - House
- Green plants - Producers
- Troph - Food
- Tertiary consumer - Lion
- Gir forests - Ecosystem
Name the 3 categories of organisms that feed on dead materials
Answer
3 categories of organisms that feed on dead materials —
- Scavengers
- Detrivores
- Decomposers
Name the 5 abiotic components of the ecosystem
Answer
5 abiotic components of the ecosystem —
- Temperature
- Water
- Sunlight
- Atmosphere (air)
- Soil
Name the 4 kinds of the ecosystem
Answer
4 kinds of the ecosystem —
- Forest Ecosystem
- Desert Ecosystem
- Pond Ecosystem
- River Ecosystem
Name the 3 categories of interdependence between the organisms
Answer
3 categories of interdependence between the organisms —
- Symbiosis
- Parasitism
- Predation
Name the 3 categories of consumers
Answer
3 categories of consumers —
- Herbivores
- Carnivores
- Omnivores
Give two examples of each :
(a) Producers
(b) Herbivores
(c) Carnivores
(d) Predators
(e) Parasites
(f) Scavengers
Answer
(a) Producers - Green Plants, Algae
(b) Herbivores - Goat, Grasshopper
(c) Carnivores - Snakes, Lizards
(d) Predators - Lion, Tiger
(e) Parasites - Mosquito, Tapeworm
(f) Scavengers - Vultures, Crows
Define Ecosystem.
Answer
An ecosystem is a self-contained area composed of all the different organisms living in it, interacting with each other, as well as interacting with the physical conditions i.e., sunlight, air, water, soil, climatic factors, etc. prevailing in the area.
Define Autotrophs.
Answer
Autotrophs are organisms that produce their own food through Photosynthesis using simple substances like Carbon dioxide and Water in the presence of Sunlight. They come at the beginning of the food chain.
Define Heterotrophs.
Answer
The organisms which cannot synthesize their own food and depend on plants and other animals for their food are known as Heterotrophs.
Define Food chain.
Answer
Food chain is the linear sequence of organisms in which each organism eats the lower member and is itself eaten by the next higher member.
Define Food web.
Answer
A network of various interconnected food chains which show complex feeding relationships is called food web.
Define Consumers.
Answer
The organisms that cannot make their own food but consume either plants or animals are called consumers.
Define Symbiosis.
Answer
Symbiosis is defined as a relationship or interaction in which both the interacting species are benefitted.
Differentiate between Flora and fauna.
Answer
Differences between Flora and fauna:
| Flora | Fauna |
|---|---|
| Flora means the plants naturally occurring in a particular area. | Fauna means the animals naturally living in a particular area. |
| Flora is the naturally grown greenery of a region. | Fauna includes all types of organisms from tiny bacteria to giant animals. |
| Flora can make their own food with the help of photosynthesis. | Fauna can't make their own food, they depend on plants for their food. |
| Some examples of flora: mosses, herbs, shrubs and trees etc. | Some examples of fauna: birds, animals, fish, insects, etc. |
Differentiate between primary and secondary consumers.
Answer
Differences between Primary and secondary consumers:
| Primary consumers | Secondary consumers |
|---|---|
| Primary consumers obtain their food from producers (plants). | Secondary consumers obtain energy by eating primary consumers (herbivores). |
| Example - krill eats grass. | Example - Small fish eats krill. |
Differentiate between parasitism and predation
Answer
Differences between Parasitism and predation:
| Parasitism | Predation |
|---|---|
| Parasitism is a relationship between two living organism of different species in which one organism called parasite obtains its food directly from another living organism called host. | Predation is an interaction between members of two species in which members of one species capture, kill and eat up members of other species. |
| Example: Tape worm or liver fluke on humans | Example: Tiger preying on deer. |
Differentiate between biotic and abiotic components
Answer
Differences between Biotic and abiotic components:
| Biotic component | Abiotic components |
|---|---|
| Living components of environment are known as biotic components. | Non-living components of the environment are known as Abiotic component. |
| Biotic components depend upon abiotic components in various ways. | Abiotic components are independent of biotic components. |
| Examples: Plants, Animals | Example: Temperature, Humidity. |
Differentiate between scavengers and detritivores.
Answer
| Scavengers | Detritivores |
|---|---|
| Scavengers feed on dead animal and plant material. | Detritivores feed on detritus or decomposing plant and animal parts as well as faeces. |
| They are larger animals. | They are smaller animals. |
| Examples: Vulture, Hyena. | Examples: Earthworms, millipedes. |
Differentiate among primary, secondary and tertiary consumers. Give one example of each in a food chain.
Answer
| Primary Consumers | Secondary Consumers | Tertiary Consumers |
|---|---|---|
| The organisms that feed on primary producers. | The organisms that feed on primary consumers. | The animals that obtain their nutrition by eating primary consumers and secondary consumers. |
| Herbivores | Either carnivores or omnivores | Carnivores |
| Obtain energy from primary producers | Obtain energy from primary consumers | Obtain energy either from primary or secondary consumers |
| Examples — Grasshopper eating grass | Examples — Frog eating Grasshopper | Examples — Snake eating Frog. |
List any three members each of the flora and fauna of tropical rain forests.
Answer
Three members of flora and fauna of tropical rain forests includes —
Flora — Evergreen trees, bamboos, ferns.
Fauna — Jungle cats, Leopards, monkeys.
Give reason/explain — Food web is important to maintain an ecosystem.
Answer
Food web illustrates the complex relationships between different species and how they are interdependent on each other for survival. Food webs show the flow of energy and matter, highlighting the importance of each organism in the ecosystem. They help maintain the natural balance of habitats, which is essential for the sustainability of animal and plant life. The complex food web imparts that in case of sudden change in population of a species, the food chain will not collapse at once and the stability of ecosystem will be maintained.
Give reason/explain — The existence of plant life is integral to the continuity and development of most ecosystems.
Answer
Plants are primary producers. Every food chain starts with plants. They supply food to nearly all terrestrial organisms, including humans. They also provide oxygen on which all organisms depend for respiration. Therefore, the existence of plant life is integral to the continuity and development of most ecosystems.
Draw the following with a suitable example :
(a) Pyramid of numbers
(b) Pyramid of biomass
Answer
(a) Diagram showing the pyramid of numbers with example is shown below:
(b) Diagram showing the pyramid of biomass with example is shown below:
