GSEB Solutions for Class 7 Science and Technology – Food Chain

GSEB Solutions for Class 7 Science and Technology – Food Chain (English Medium)

GSEB SolutionsMathsScience
Exercise 123:

Solution 1(a):

Name	Food (what they eat?)
1. Snake	Frog , Birds, Rodents
2. Peacock	Grains, Insects, Snakes, Small reptiles
3. Deer	Green leaves, Grasses, Carrots
4. Tiger	Rodents, Small reptiles and mammals
5. Ant	Fruits, Seeds
6. Fish	Small aquatic plants, Seaweed
7. Frog	Small insects, Flies, Mosquitoes, Moths
8. Duck	Grasses, Aquatic plants, Fish, Insects
9. Spider	Trapped insects
10. Lizard	Ants, Termites, Bees

 

Exercise 125:

Solution 1(a):

If sun does not appear, it means that the Earth has stopped spinning. There will be no heat in the environment, crops will not survive, human beings and animals will feel cold and the whole ecosystem will be disrupted.

Exercise 126:

Solution 1(a):

The deer population remained the same after 5 years because the environmental factors remained at equilibrium. They fed on the food that was available in the forest and there was no intervention of human beings such as hunting the deer and affecting the forest life.

Exercise 127:

Solution 1(a):

After 3 years of obeyance of order, there must be human intervention like hunting. There may also be introduction of foreign species to the native land that may have caused the decline of the deer population.

Exercise 128:

Solution 1(a):

The above diagram depicts a five step food chain. Grass gets its food from solar energy, grasshopper consumes grass which is consumed by snake and the hawk in turn eats the snake.

Exercise 130:

Solution 1(a):

Living things (Biotic factors)-

1. Spider
2. Animals like tiger, lion, frogs etc
3. Herbs and shrubs
4. Other insects like ants, beetles, worms

Non-living things (Abiotic factors)-

1. Cave
2. Rocks, dirt, water, air and temperature

Exercise 131:

Solution 1(a):

1. Name of place- Pond
2. Non-living things include soil, water, climate, temperature.
3. Insects like termites, ants, worms.
4. Animals like fishes, deer, cranes, ducks.
5. Yes, dirtiness includes soil, dust from rocks.
6. Useless things in a pond are seaweeds, decaying organic matter.
7. Yes, there occurs water and soil pollution. The dirt in the pond pollutes the water thereby causing harm to the aquatic plants and animals. The soil present near the pond erodes.

Exercise 132:

Solution 1(a):

Endangered Animals	Extinct Animals
Asian elephant	Dodo bird
Bengal tiger	Dinosaurs
Blue whale	Passenger pigeon
Giant Panda	White dolphin
Black Rhino	Quagga

Solution 1(b):

1. Preventing overgrazing of animals.
2. Preventing forest fire.
3. Planting more trees (afforestation).
4. Statistical survey of animal populations.
5. Construction of zoos, national parks and sanctuaries.
6. Participate in the awareness program for conservation of wildlife like slogans and debates.

Exercise 133:

Solution 1:

1. Green plants – They produce food by the process of photosynthesis that include trees, bushes and grasses
2. Herbivores – They directly eat plants and are known as the primary consumers likedeer, rabbit, rats.
3. Carnivores – They are the biotic components known as the secondary consumers such as tigers, lion.
4. Parasites – They live inside or on the body surface of another organism and obtain food from it.
5. Decomposers – They live on dead and decaying plant and animal bodies that include bacteria, fungi etc.

Solution 2:

1. Temperature – The energy obtained from sunlight is essential for the production of food by photosynthesis.
2. Air – Oxygen from the air is essential to animals for respiration and is also an agent for dispersal of seeds, fruits.
3. Water – It is required for various biochemical reactions which occur in organisms.
4. Temperature – Hot, mild or cold temperature influences the kind of body functions of plants and animals.
5. Soil – Contains water and mineral nutrients that help in the growth of plants.

Solution 3:

Food chain can be defined as the sequential arrangement of organisms in which all organisms are inter-related and depend on each other for their food.
For example: The light energy of sun is trapped by green plants i.e. herbivores who constitute the first level. These green plants are eaten by herbivores and herbivores, in turn, become the source of food for carnivores.

Solution 4:

Animals – Camel, Scorpion, Desert snakes
Birds – Eagles, Owls, Quail, Doves
Insects – Desert cricket, beetles, spiders
Plants – Cacti, Rock plants, Elephant tree, Willow tree