GSEB Solutions for Class 7 Science and Technology – Environmental Equillibrium (English Medium)
GSEB SolutionsMathsScience
Exercise 134:
Solution 1(a):
Biotic components include plants and animals.
Solution 1(b):
Abiotic components include air, sunlight, temperature and soil.
Solution 1(c):
Abiotic factors include light, temperature, chemical products, water and atmosphere. For example, light is an essential abiotic factor in the ecosystem because it constitutes the main supply of energy for organisms. The plants with chlorophyll can change light energy into chemical energy.
Biotic factors cannot survive without abiotic factors which will disturb the environment.
Exercise 135:
Solution 1(a):
The environmental equilibrium may be disturbed due to the introduction of new species, sudden death of some species, natural hazards or man-made causes.
Earthquakes, various types of volcanic eruptions, tsunami, the devastating effects of human activities such as forest clearing and the introduction of invasive species disturb the environmental equilibrium.
Solution 1(b):
Snakes, reptiles and monkeys are found rarely or in small numbers around us.
Exercise 136:
Solution 1(a):
Asian elephant | Marbled cat | Olive Ridley turtles | Sea turtle | Indian vulture |
Bengal tiger | Red panda | Hornbill | Sawfish | Lemur |
Blue whale | Snow leopard | Black rhino | Redheaded vulture | Javan rhinoceros |
Barasingha | Sloth bear | Himalayan wolf | Quail | Monk seal |
Clouded leopard | Swamped deer | Flying squirrel | Great Indian Bustard | Mountain gorilla |
Indian wild ass | Yak | Roofed turtle | Owlet | Ivory billed woodpecker |
Lion tailed macaque | Wild goat | Gharial | Crane | Giant salamander |
Exercise 137:
Solution 1(a):
- Different types of habitat can be studied and regular statistical surveys of animal populations can be carried out.
- Protection of endangered species by creating national parks, sanctuaries and zoos.
- Launching of successful captivity breeding programmes for these animals.
- Many organizations like Indian Board of Wildlife and World Wildlife Fund take sole responsibility of conservation of endangered animals.
Solution 1(b):
Birds found in highest numbers | Birds found in less numbers or are rare | Birds never found |
Crow | Parrot | Kiwi |
Pigeon | Sparrow | Woodpecker |
Hummingbird | Swan | Vulture |
Peacock | Duck | Eagle |
Exercise 139:
Solution 1(a):
Albatross | Himalayan quail | Pink headed duck | Spoon billed sandpiper | Black tailed Godwit |
Siberian crane | Indian vulture | Forest Owlet | White backed vulture | Lesser flamingoes |
White bellied heron | Great Indian Bustard | Bengal Florican | Red headed vulture | Eurasian curlew |
Solution 1(b):
- They help in growth of trees by removing parasites and damaging insects.
- They help in transporting seeds.
- They also help with pollination.
Exercise 141:
Solution 1(a):
The aquatic animals include sharks, dolphins, fishes, eels, whales, shrimps, crabs, starfishes, stingrays and turtles.
Exercise 142:
Solution 1(a):
Trees found rarely | Trees not found at all |
Mangroves | Nilgiri Holly |
Milkwort | Kerala legume tree |
Whisk fern | Woolly stalked Begonia |
Ebony | Jeemikanda |
Umbrella thorn | Spiderwort |
Musli | Water lily |
Exercise 144:
Solution 1(a):
- Preventing overgrazing of animals as they eat young trees.
- Practices such as safe campfire and safe fireworks should be adopted near forest areas in order to prevent forest fire.
- Large scale afforestation can be practiced to protect and conserve trees.
Exercise 145:
Solution 1:
- Introduction of foreign species in a native environment causes ecological imbalance.
- Habitat loss is also an important problem that causes imbalance in environment.
- Climate change is also altering migratory species patterns.
- Improper use of non-renewable resources also causes loss in ecological imbalance.
- Deforestation and environmental pollution is also a major cause for environmental imbalance.
Solution 2:
Environmental equilibrium refers to the balance in the environment and all the organisms living in it.
- It is very important for continued existence and survival of organisms and stability of environment.
- It is also important for adaptation of organisms to the environment and vice versa.
- Interactions among organisms maintain diversity and in destroying or enhancing one species in a local ecosystem, one may destroy the whole system in time.
For example, bacteria are vital for maintaining the living world. Some of them are producers that capture energy by photosynthesis while others are decomposers that break down the nutrients in dead matter and the atmosphere.
Solution 3:
- We can protect forests by planting more trees and preventing forest fires.
- We can conserve wildlife that is on the verge of extinction.
- Conservation of habitat for the wild species may be taken care of so that they feel safe and secure.
- Protection of these species by constructing national parks, zoos and sanctuaries.
- We can reduce the environmental pollution of air, water and soil in order to maintain environmental equilibrium.