NIOS Class 10 Science & Technology Chapter 29 Solution

NIOS Class 10 Science & Technology Chapter 29 Solution – Natural Environment

NIOS Class 10 Science & Technology Solution Chapter 29 Natural Environment. NIOS Class 10 Science & Technology Chapter 29 Question Answers Download PDF. NIOS Class 10 Science Notes.

NIOS Class 10 Science & Technology Chapter 29 Solution



10th  (Secondary)


Science and Technology (212)

Question Answer, Solution, Notes


1) Sunlight forms the abiotic component of ecosystem, name one biotic component.

Ans: –  The biotic components in the ecosystem are animal.

2)Why are plants called producers? Which trophic level do they occupy in an ecosystem?

Ans: –  As the plant prepare their food from the sunlight which then transfer to the other components in the ecosystem this known as producer.

Plant occupies in the primary or first level in ecosystem.

3) Give one reason in support of the statement that “food web is a jumble of food chains”.

Ans: – The word food web is a jumble of food chain means animal eat various food in order for their food and energy requirements.

4) Construct one food chain and one food web from the following:

Tiger, grains, vulture, frog, snake, grass, cat, sheep, peacock, wolf, rabbit, phytoplankton, small fish, rat, large fish.

Ans: –


1)Name any two ways which are responsible for adding carbon dioxide in the atmosphere.

Ans: –From different pollution there come carbon in the atmosphere like from the car, factories or coal plant.

2) Name the bacteria which live in the roots of the leguminous plants and are responsible for nitrogen fixation.

Ans: – Rhizobium present in the root of a tree.

3)What is the process of conversion of free atmospheric nitrogen into nitrites and nitrates called?

Ans: –  Ammonification is the process in which the nitrogen conversion into nitrates and nitrites.

4) What is the role played by denitrifying bacteria and nitrifying bacteria in the nitrogen cycle? Give the name of one denitrifying bacteria and one for nitrifying bacteria.

Ans: – Denitrifying bacteria helps to reduced nitrate to nitrogen in the soil.

  • Nitrifying bacteria does reverse of denitrifying bacteria like converts ammonia to nitrate.
  • Denitrifying bacteria is – Pseudomonas.
  • Nitrifying bacteria is Nitrobacter.

5)Mention any one role that you play in the (i) nitrogen cycle and (ii) carbon cycle.

Ans: – (i)Release the N2 as nitrogen compounds by urine.

(ii) By releasing CO2 to the atmosphere and by this process going on.

6) Nitrogen is an essential component of the proteins and nucleic acids in living beings. Mention any one way by which you obtain nitrogen for your growth.

Ans: – If we took food then by this nitrogen go into our body.

7) Mention one way in which increasing deforestation by humans is influencing the carbon cycle.

Ans: – By spreading awareness among the people in that locality with strict law.


1) Why are leaves of water lily coated with wax on the upper surface?

Ans: – This wax present on the surface in the leaves makes this water repellent so these leaves are coated with wax.

2) Name two tree dwellers.

Ans: – The tree dwellers are flying frogs and flying lizards.

3)Enumerate the adaptations of birds that enable them to fly so easily (Anytwo).

Ans: – The adaptation is

  • Streamlined body
  • hollow bones,
  • strong flight muscles etc.

4)How are penguins able to survive in the extreme cold conditions? (Any twoadaptations).

Ans: –These adaptations are

  • Presence of thick layer of densely packed feathers flippers.
  • legs areadapted to reduce heat loss.

5)Why do the desert plants have fewer stomata?

Ans: –For the reducing of photosynthesis process.

6)Humans are not adapted for aquatic life. List any two challenges that you would face when you go for swimming in a pond/lake and the ways by which you would overcome them and become an effective swimmer.

Ans: –  The challenges are Keeping afloat, breathing etc which will face.

And for overcome move hands and feet and keep the nose above water to breath


1) How is the sucker fish benefitted by attaching itself to the shark’s body? What type of association is it?

Ans: – The sucker fish benefitted by attaching itself to the shark’s body by diapering widely.

This type of association is known as commensalism.

2)If alga provides food to the fungus that lives on it, what does the fungus dofor the alga?

Ans: – If alga provides food to the fungus that lives on it the fungus provides shelter and mineral for the alga.


1)When does the population density increase?

Ans: – The population density will increase if there is low death rate and high birth rate.

2)What is the difference between Emigration and Immigration?

Ans: – Emigration: – It is the permanent outward movement of some population.

Immigration: – It is the permanent inward movement from outside into a given population.

3) What is lag phase?

Ans: – When individuals enter a unoccupied area, the growth is slow at first this phase is known as lag phase.


1) What is an ecosystem? Name the various components of an ecosystem.

Ans: – In an area on the earth where different types of animals, plant species are located and a wide variety of their number is presented is known as ecosystem.

The various components of ecosystem are plants, animal, different bacteria as well.

2) Is detritus a biotic component or is it an abiotic component of an ecosystem?

Ans: – The detritus is a biotic component in an ecosystem.

3) What is the function of Nitrosomonas in nitrogen cycle?

Ans: – Nitrosomonas is a nitrying bacteria which converts the nitrogen from ammonia in soil.

4) With the help of suitable examples differentiate between the detritus and grazingfood chain.

Ans: – The grazing food chain is different from the detritus food chain as in detritus food chain starts from the dead organ to animal and in grazing starts from the producer which produce food from sunlight.

5)What is the significance of food chain and food web?

Ans: – There is various need of a food chain and food web as because of this the different particle and their dependency is known from that.

6) Why does the energy decrease as we go along the food chain from producers totertiary consumers?

Ans: – As from the food chain it is clear that the primary substance in ecosystem present in more number and gradually this decrease in ordered to the upper category.

7) What will happen if all the animals are removed from a pond?

Ans: – If all the animal are removed from the water of pond, then there will be an increase in the number of plants in the pond and because of that oxygen shortage will happen.

8) Why is the number of trophic levels restricted to four or five in a food chain?

Ans: – As after that tropic level the same circle is repeated or the cycle is started from the primary again so there the numbers of tropic levels are limited in numbers.

9) What is the difference between energy flow and biogeochemical cycle in an ecosystem?

Ans: –In a biogeochemical cycle the energy transfer from the different components in natural way but in energy flow transfer of energy from producer to 4 to 5th levels included plant and animal.

10) How are camels able to survive in extreme heat?

Ans: – In the back of the camel there present a water storage so by this in harsh condition the water is used in so the camel would survive in the extreme heat.

11) Why do polar bear have thick fur over their body?

Ans: – The polar bear has thick fur in its body. This fur helps the polar bear body warm in the very cold condition in all the season in the polar region.

12) Compare the S-shaped pattern of population growth with the J-shaped pattern of population growth.

Ans: –

13) What is population dispersal? What are the two types of population dispersal?

Ans: – The population dispersal means the settlement of a population in a particular area. The two types of population dispersal are uniform dispersal and random dispersal.

14) What is the main cause of population explosion?

Ans: – The main reason behind the population explosion is the high birth rate and low death rate in the society or in a country.

15) Do you think population remains static? Support your answer with suitable explanation.

Ans: –  Population remain static which is not possible as the death rate is always low as compared to birth rate because the possibility of the equal this both rate is less.

16)Try to complete the table given below.

Ans: –

  Features How is the feature

advantageous to the


Name of the

plant/animal if is


1 Nostrils positioned near the

top of the head of animals

For breathing Dolphin’s
2 In sponge or root To store water cacti
3 Loss of water by excreting

uric acid in water.

For Secretion of unwanted substance In animal.
4 Hollow bone Oxygen intake during flying Birds
5 Feathers in the surface of the body Trap air to keep the body warm and help the bird to fly Birds.
6 Presence of flippers and legs Foe the movement Dolphin
7 Thin, bread leaves with a

large number of stomata on the underside of leaves

For the photosynthesis process In plants leaf
8 Bladder present in body or swimblader Acts as a water repellent

and allows them to remain

afloat on the surface of


Water lily

 17) Extensive poaching and hunting has reduced the tiger population in Asia toa dangerous level.

(a) What are they hunted for (2 points).

Ans: – The hunted for the skin and the teeth of the tiger while poaching from Asian region.

(b) Draw a food web with tiger as the top-level carnivore (At least 2 food chain to be shown)

Ans: –

(c) What effect will removal of the tiger have on (i) the herbivore (ii)producer?

Ans: – The herbivores are the living being who takes their food from the plant and this eaten by carnivorous. So, if the tigers are removed these herbivores will increase and plant will be finishes speedy.

As a result of that the producer will be decrease as the number of herbivores in an ecosystem will be increase.

Updated: March 3, 2022 — 11:36 pm

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