6 Science Chapter 9 Living Organisms And Their Surrounding

Chapter Notes and Summary
• Living organisms can be found every where on this earth such as plains, mountains, deserts and oceans.
• All living organisms need food and other materials from their surrounding to survive.
• Some living organisms develop some special features to help them survive better in their local weather conditions.
This characteristic of living organisms is called adaptation.
• non-living things and other living organisms that affects a particular living organism are referred to as its environment. Environment means surroundings.
• study of relationship of a living organism and its environment is known as ecology.
• All living organisms are called biotic components.
• All non-living things present in environment are called abiotic components.
• A habitat is a place in environment where a living organisms lives and grows naturally.
• All living conditions such as proper food, temperature, shelter and climatic conditions are provided by habitat that are required for organisms to survive.
• Habitats are of two types—Terrestrial habitat and Aquatic habitat.
• surface of land acts as a terrestrial habitat.
• Terrestrial habitats include deserts, grasslands, forests and mountains.
• Water bodies of all forms act as aquatic habitat.
• Aquatic habitats include ponds, lakes, rivers, sea and oceans.
• Some organisms such as frogs, toads etc are capable of living on land as well as in water. These animals are known as amphibians.
• Some organisms like birds that spend a considerable amount of time suspended in air are aerial organisms and such habitat is called aerial habitat.
• Some organisms like monkeys, squirrels etc that spend most crucial part of their lives on trees are arboreal animals and such habitat is called arboreal habitat.
• A desert is a region with scanty rainfall. annual rainfall is less than 25 cm.
• A desert is usually very hot during day and cold at night.
Adaptive features of plants in desert :
• Plants have a well-developed and deep root system to reach and draw underground water.
• stem is modified to perform function of photosynthesis in Cactus.
• Such plants are usually covered with a waxy coating.
• Animals like rats and snakes in deserts spend hot days inside burrows and under ground to escape heat.
• Camel is called ‘Ship of Desert’.
• A camel can drink enormous amount of water at a time (i,e,, 120 litres) that can last for a long time. It has thick skin to keep heat away.
• Polar regions are covered with snow.
• Adaptive features of plants in mountain region
• Trees are conical in shape which allow snow to slide off easily.
• leaves have a needle-like shape and are covered with a waxy coating. This prevent loss of water due to transpiration.
• condition in which animals undergo a long sleep in polar regions is called hibernation.
• Grasslands provide a rich variety of flora and fauna including grasses.
• Oceans are marine water habitats.
• ponds, lakes and rivers are fresh water aquatic habitats.
• plants which grow in water are known as aquatic plants.
• Aquatic plants are categorized as free floating, partly submerge and completely submerged.
Characteristics of Living Things :
• They can grow.
• They can move on their own.
• They reproduce themselves.
• They release energy from food and undergo respiration.
• They get rid of waste materials from their body and undergo excretion.
• They have a definite life span.
• They are made up of living cells.
• All living organisms need food to survive.
• Earthworm breathes through their skin.
• Fish use gills to obtain dissolved oxygen from water.
• Plants exchange gases through tiny pores found on their leaves. These tiny pores are called stomata.
• All living things respond to changes around them.
• leaves of ‘touch-me-not plant (Mimosa pudica) close or fold when some one touches them. It means it shows responses to stimuli.

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