Question of Exercise 5 (True -False) Improvement of food resources

Improvement of food resources of Class 9

Vitamin C is obtained in excess from milk.

Frequently Asked Questions

Soil is a mixture of

A: Minerals

B: Dead and living organisms

C: Air and water

D: All the above



Soil may be a mixture of minerals, dead and living organisms (organic materials), air, and water. These four ingredients react with each other in amazing ways, the soil making is regarded as our planet's most dynamic and important natural process.

Final Answers:-

Hence the correct option is D i.e All the above


Multicellular organisms have division of labour Explain


Explanation :- 

In unicellular organisms, a single is capable of performing all the activities of the cell as they have simple body organization.

  • Since, the level of complexity in multicellular organisms is very high. Each and every cell performs a special function.
  • Multicellular organisms show clear division of labour as their body has to perform many functions. 
  • So, to perform these functions efficiently, cells are specialized to perform special functions.
  • This is called division of labour.

Final answer :- 

Hence,this is the explanation that multicellular organisms have division of labour.


Collagen fibers are secreted by

A: Mast cells

B: Macrophage

C: Histiocytes

D: Fibroblasts



Explanation :
The main structural protein of varied connective tissues in animals is Collagen.
Fibroblast cells secrete it.
 It is found in fibrous tissues, such as ligaments, tendons, and skin. 
Its appearance is elongated fibrils type.
Final Answer :
Hence, the correct option is D, i.e. Fibroblasts.

What do you understand by crop rotation

Giving a suitable example, explain how this practice is beneficial to the farmers.




The practice of successive cultivation of different crops in a specific manner in the same field is known as crop rotation.

 For example a farmer plants corn crops and after harvesting corn he can plant legumes because corn absorbs nitrogen from the field and legumes return that nitrogen back to the field.

Crop rotation is beneficial for farmers for mainly following reasons 

  • Plants that fix nitrogen, such as peas and other legumes, enhance the quality of soil along with high productivity.
  • If shallow-rooted and deep-rooted plants are grown in an alternated pattern in a given area, they draw nutrients from the soil at different depths and increase the fertility of soil.
  • Farmers practice this technique to minimize soil erosion and to increase water efficiency.
  •  Farmers who practice crop rotation technique do not need to let fields barren (crop-free)

Final Answer

Hence, production of successive cultivation of different crops in a particular manner in the same field is known as crop rotation.



Write the formula of ozone



The formula of ozone is O₃.

Three oxygen atoms make up ozone, a highly reactive gas. It is a natural and man-made product that exists in the upper

(stratosphere) and lower (troposphere) atmospheres of the Earth (the troposphere).

Ozone has a positive or negative impact on life on Earth depending on its location in the atmosphere.



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