Lakhmir Singh & Manjit Kaur: Our Environment, Solutions- 1 | Science Class 10 PDF Download

Page No - 226

Question 1:
What is the functional unit of the environment comprising of the living and non-living components called ?
Solution :
Ecosystem.

Question 2:
Name two natural ecosystems and two artificial ecosystems.
Solution :
Natural ecosystems – Grass land and forest. Artificial ecosystems – Parks and Gardens.

Question 3:
Which one of the following is not a terrestial ecosystem ?
Forest, Grassland, Aquarium, Desert
Solution :
Aquarium.

Question 4:
Why are plants called producers ?
Solution :
Plants are called producers because green plants prepare their own food from simple inorganic substances like carbon dioxide and water by using sunlight energy in the presence of chlorophyll.

Question 5:
What name has been given to those organisms which break down the complex organic compounds present in dead animals and plants ?
Solution :
Decomposers.

Question 6:
What are planktons ?
Solution :
Planktons are very minute or microscopic organisms freely floating on the surface of water in a pond, lake, river or ocean.

Question 7:
State whether the following statements are true or false :State whether the following statements are true or false :
(a) In biology, human beings are called producers.
(b) Secondary consumers and tertiary consumers, both are carnivores.
Solution :
(a) False.
(b) True.

Question 8:
Which category of organisms forms the starting point of a food chain ?
Solution :
Producer.

Question 9:
Which of the following belong to the same trophic level ?
Goat; Spider ; Plants ; Hawk ; Rat .
Solution :
Goat and Rat (Both are herbivores).

Question 10:
Which of the following belong to the same trophic level ?
Tree ; Frog ; Snake ; Grass ; Lizard
Solution :
Tree and Grass (Both are producers).

Question 11:
Write an aquatic food chain.
Solution :

Question 12:
Name the organisms belonging to the second and the fourth trophic levels in the food chain comprising the following :
Frogs, Plants, Snakes, Hawk, Insects
Solution :
Second trophic level: Insects Fourth trophic level: Snakes

Question 13:
What are the various steps of food chain called ?
Solution :
Trophic levels

Question 14:
Construct a food chain comprising the following :
Snakes, Hawk, Rats, Plants
Solution :

Plants   ->  Rats   ->  Snakes   ->  Hawk 

Question 15:
Arrange the following in a food chain :
Fish, Algae, Small animals, Big Fish
Solution : 

Question 16:
Which organisms belong to third and fourth trophic levels in the food chain comprising the following ?
Rats, Plants, Hawk, Snakes
Solution :
Third Trophic level: Snakes.Fourth trophic level: Hawk.

Question 17:
Which one term in the following includes the others ?
air, flora, fauna, environment, water, sunlight, soil
Solution :
Environment.

Question 18:
A food chain represents a unidirectional flow of X. What is X ?
Solution :
Energy.

Question 19:
Fill in the following blanks with suitable words : Fill in the following blanks with suitable words :
(a) Decomposer organisms are……………. in their action.
(b) In nature, all green plants are……………. whereas animals are consumers.
(c) A series of organisms, each of which feeds on the next organism, the beginning of which is a green plant, is called a…………….
(d) The science that deals with the inter-relationships of living things with one another and their environment is called …………….
(e) Plastic is a……………. material whereas paper is a……………. material.
Solution :
(a) Specific.
(b) Producers.
(c) Food Chain.
(d) Ecology.
(e) Non – biodegradable; Biodegradable.

Question 20:
Explain the terms ‘producer’ and ‘consumer’. Give two examples of producers and two of consumers.
Solution :

1. Producers are the organisms which can be prepare their own food from simple inorganic substances like carbon dioxide and water by using sunlight energy in the presence of chlorophyll. Example – Green plants and certain blue-green algae
2. Those organisms which consume food (eat food) prepared by producers are called consumers. Example – Lion and Tiger.

Question 21:
(a) Define decomposers. Name one decomposer.
(b) What is the role of decomposers in the ecosystem ?
Solution :
(a) The micro-organisms which break down the complex organic compounds present in dead organisms like dead plants and animals and their products like faeces, urine, etc., into simpler substances are called decomposers. Example – Bacteria and Fungi.
(b) The decomposers help in decomposing the dead bodies of plants and animals, and hence act as cleansing agents of environment.

Question 22:
What is meant by a primary consumer, secondary consumer and a tertiary consumer ? Give one example of each.
Solution :

1. The animals which eat only plants are called Herbivores. All herbivores are primary consumers. Example – Goat
2. The small carnivores which feed on herbivores (primary consumers) are called secondary consumers. Example – Frog
3. The Large carnivores (or top carnivores) which feed upon the small carnivores (secondary consumers) are called tertiary consumers. Example – Lion