Skip to main content

Biology notes for Class 10 CBSE: Lesson 6 - Life Processes Part -1

Copyrighted Material. Author Reserves All Rights
  1. What are autotrophs?
    Ans.
    Living organisms that are capable of making their own food from inorganic substances (i.e.carbon dioxide and water) using Sun's light energy, are called autotrophs. E.g. all green plants and some kind of bacteria.


  2. What are heterotrophs?
    Ans. Living organisms like animals and human beings that depend on other organisms for their food are called heterotrophs.


  3. What is autotrophic nutrition?
    Ans. The mode of nutrition by which some living organisms like green plants make their food from inorganic substances by trapping light energy from the Sun, is called autotrophic nutrition.


  4. What is heterotrophic nutrition?
    Ans. The mode of nutrition by which living organisms obtain their food from other living organisms, is called heterotrophic nutrition.


  5. Define photosynthesis.
    Ans.The process by which green plants take in organic substances (carbon dioxide and water) from the outside surroundings and convert these into carbohydrates in the presence of sunlight and chlorophyll is called photosynthesis.


  6. List the steps involved in photosynthesis. OR List the events that occur during photosynthesis.
    Ans.Steps involved in photosynthesis:
    • Light energy is absorbed by chlorophyll and is converted into chemical energy.

    • Water molecules split into hydrogen and oxygen.

    • Carbon dioxide is reduced (converted) to carbohydrate.


  7. What is chloroplast?
    Ans.The cell organelle present in the green leaves of green plants that contain chlorophyll is called chloroplast.


  8. Write an activity to show that chlorophyll is essential for photosynthesis.
    Ans.
    Activity
    • Take a potted plant with variegated leaves and keep it in a dark room for three continuous days.
    • After three days, take the potted plant from the dark room and keep it in sunlight for six hours.
    • After six hours, pluck a leaf from the plant and mark the green areas in the leaf and trace these on a sheet.
    • Keep the leaf in boiling water for few minutes and then immerse it in a beaker containing alcohol.
    • Carefully place the beaker in a water bath and heat till alcohol begins to boil.
    • The leaf decolourises on boiling in alcohol.
    • Place the decolourized leaf in a petri dish and add few drops of iodine solution to it.
    • Take out the leaf and rinse off the iodine solution.
    • Observe the color of the leaf and compare it with the tracing of the leaf that was taken before boiling it in alcohol.
    • It is observed that the part of the leaf that was green turns blue black which indicates the presence of starch. While the non-green parts of the leaf turn yellow.
    • The above activity proves that only the cells containing chlorophyll synthesized starch. Thus it is concluded that chlorophyll is essential for photosynthesis.
    Note for the students:
    • A leaf that has both green part containing chlorophyll and non-green part that do not contain chlorophyll is known as a variegated leaf.
    • Starch turns blue black when iodine is added to it.


  9. Answer the following questions based on the above activity:
    1. Why the potted plant is kept in the dark room for three days?
      Ans.The potted plant is kept in the dark room for three days so that all the starch in the green parts of the leaves gets used up.


    2. Why the leaf is boiled in alcohol?
      Ans.The leaf is boiled in alcohol to decolorize it.


    3. Why some parts of the leaf turned blue black on adding iodine solution?
      Ans. Some parts of the leaf turned blue black on adding iodine solution as these parts contained starch. Starch turns blue black when iodine is added to it.


  10. Explain the closing and opening of stomatal pores.
    Ans. The opening and closing of stomatal pores are controlled by the guard cells. These cells swell when water flows into them causing the stomatal pore to open. The guard cells shrink when water flows out of these cells causing the stomata to close.


  11. What is meant by parasitic mode of nutrition?
    Ans. The mode of nutrition by which some organisms like leeches, hookworm, tapeworm, ticks, cuscuta etc derive their nutrition from plants or animals without killing them, is known as parasitic mode of nutrition.


  12. What are parasites?
    Ans. Living organisms that get their nutrition from plants or animals without killing them are called parasites. E.g. cuscuta, lice, leeches, hookworm etc.


  13. Explain briefly the nutrition in amoeba.
    Ans. Amoeba is a unicellular organism. When it comes in contact with food, the cell surface temporarily changes into finger-like projections called pseudopodia which fuse over the food particle forming a food vacuole.
    The complex substances inside the food vacuole are broken down into simpler ones which then diffuse into the cytoplasm of amoeba. The remaining undigested material moves to the body surface and is thrown out of the body.


  14. List (Name) the organs of human alimentary canal
    Ans. The human alimentary canal is a long tube extending from mouth to anus with different organs in various regions specialized to perform specified functions. The organs of alimentary canal are:
    1. Mouth
    2. Tongue
    3. Oesophagus (food pipe)
    4. Stomach
    5. Pancreas
    6. Liver
    7. Gall Bladder
    8. Bile duct
    9. Small intestine
    10. Large intestine
    11. Rectum
    12. Anus

Popular posts from this blog

Farewell Speech By School Principal to Outgoing Students

Author Reserves All Rights.
Listen to the speech in my YouTube Channel:
This sample speech would be helpful for the school principal to deliver on the occasion of school farewell day party.

Respected teachers and my dear students,

Good Morning / Good Afternoon to each one present here and a very warm welcome to you to the school farewell party.

It's a nostalgic feeling as I remember my student life in school and my school farewell party. I am sure we all have mixed feelings on this day which is a blend of joy and sadness. On one hand you feel enthusiastic as you will be stepping into a completely new different world where you will find relatively more freedom than in a school life. While on the other hand you will feel sad as you have to depart from your school / classmates.

My dear friends the time has come to bid you all farewell with a heavy heart from this esteemed institution which protected you, cared for you, supported you and guided you all these years.

The institution has…

Republic Day Speech For School Principal

Last Update: 12.01.2020

Author Reserves All Rights.

This Republic Day speech would be useful for the school principal to deliver on 26 January.

Vande Mataram!


Esteemed teachers and my dear students

Wish you all a Happy Republic Day!

Today we all have gathered here to celebrate our 71stRepublic Day. On this auspicious occasion I extend my heartiest greetings and good wishes to you all. As we all know about the importance of Republic Day, I need not speak much about this special day. However we need to be grateful to the founding fathers who formulated and drafted an exemplary Constitution of India that has steered India towards progress and development. Due to the untiring efforts of the great leaders / freedom fighters of our nation under oppressive conditions, we / you all are fortunate of being born in independent India. Now we as the citizens of this great nation and you children as the future citizens of the country, need to re-dedicate ourselves to build a stronger and developed …

How To Perform Aksharabhyasam At Home And Basar temple

Aksharabhyasam is a traditional religious function of Hindus. 'Akshara' means letters (alphabets) in Sanskrit and 'abhyasam' means practice. It is also known as 'Vidyaarambham' which literally means starting of education. In this function a child is given initiation for writing / education. With this function the child is ready to receive formal education in a school. The function is performed in different ways in different regions of India.

In the olden days, aksharabhyasam was performed when the child was 5 years old. But presently because of early education at Kindergarten level, parents perform this ceremony when the child is in his 3rd year i.e. after the child completes 2 years. Normally there is a belief that aksharabhyasam should not be performed after the child completes 3 years and is in its 4th year.

The function can be performed either in a temple or at home.
Procedure to perform aksharabhyasam at home Engage a priest and fix an auspicious day / ti…