Important points for class 6th

Our Environment

Ans C 1 Rain water harvesting  -Rain water harvesting is a way to use and recycle rain water. The rain water is collected through pipes that take it underground and store it in tanks to be used later .In metropolitan cities like Delhi we collect rain water at the terrace and through pipes it is brought down to the tanks ,pits or wells.

This rain water can be used for various purposes after filtration. If rain water is not harvested it will be wasted and we will run short of water .

Ans.C2 We segregate the two type of wastes so that we can dispose them in an ecofriendly manner. The kitchen waste  can be made to be decomposed to form compost for the plants while the plastics can be recycled for reuse.Twin bin allows

1         the separation of waste  and 2  ecofriendly disposal and recycling of waste.

Blue bins are used for disposing off nonbiodegradable waste like plastic and green are used for disposing biodegradable wastes likes peels ,leaves etc.

 

Ans .C3   1 Swich off fans and lights when not required .

               2  Reduce the usage of Air conditioners

               3 Celebrate birthdays by gifting saplings to each other

              4  Use  less water in bathing ,brushing teeth etc.

             5  Use more of jute and cloth bags instead of polybags.

 

Ans.C4  The carbondioxide obtained from air is essential for photosynthesis.

 

Ans.C5  Repair the leaking taps and Use  less water in bathing ,brushing teeth etc.

 

Ans c6 Plastic is very harmful because  they can not be broken down by  decomposers . They get piled up and block the sewer lines. Burning of plastic produces harmful gases .So we should never use polybags rather we should use jute or cloth bags.

D Answers

1The herbivores will get more energy because they directly eat plants .

2They are black in color and do not have sweat glands to release their heat so they cool themselves in water.

3The  water that is evaporated from earth’s surface makes clouds which enter into the water cycle again.

4Decomposition of dead animals is very important for –1 recyclying of materials present in them and ---2 they help in cleaning up the earth

5  (1)Autotroph---- Those organisms which make their food on their own and donot depend upon others for food e.g. green plants .they have chlorophyll.

 Heterotrophs ----Those  organisms which depend upon others for food because they can not make their own food e.g. cows lions etc.They donot have chlorophyll.

(2) Decomposers--- The organisms which derive their nutrition from dead and decaying organic matter are called decomposers.They break down complex matter and help in recyclying e.g. fungi and bacteria

  Scavangers--- Animals and birds that consume dead bodies of animals are called scavangers e.g.—vultures,jackalsetc.They help in cleaning up the earth.