CBSE Class 8 Science Chapter 2 Microorganisms Friend And Foe Activities

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CBSE Class 8 Science Chapter 2 Microorganisms, Friend And Foe Activity Ideas Activity 1

Aim: To show the presence of microorganisms in soil and pond water.

Materials Required: Soil, water, two beakers, pond water, microscope, dropper, and slide.

Read And Learn More CBSE Class 8 Science Activities

Procedure

  1. Collect some moist soil from the field in a beaker A and add water to it.
  2. Take another beaker, B, and pour some pond water into it.
  3. After the soil particles have settled down, put a drop of water from the beaker A with the help ofdropper on a slide and observe under a microscope.
  4. Similarly, take a few drops of water from beaker B with the help ofdropper, spread them on a glass slide and observe through a microscope.

” Cbse Class 8 Science Chapter 2 Activities “

Observation: We will observe tiny organisms moving around in both slides.

Conclusion: From this activity, we can conclude that soil and pond water contain many microorganisms.

CBSE Class 8 Science Chapter 2 Microorganisms Friend And Foe Activity's

” Microorganisms Friend And Foe Class 8 “

CBSE Class 8 Science Chapter 2 Microorganisms Activity For Better Understanding Activity 2

Aim: To show the effect of yeast on dough.

Materials Required: 1/2 kg Flour (atta or maida), sugar, warm water, yeast powder, and a lid.

Procedure:

  1. Take 1/2 kg flour (atta or maida), add some sugar, and mix with warm water.
  2. Add a small amount of yeast powder and knead to make a soft dough.
  3. Cover the dough and keep it aside for two hours.

Observation: We will observe that the dough has risen and its volume has increased

CBSE Class 8 Science Chapter 2 Yeast Effect Fermentation

” Presence Of Microorganisms In Soil And Water “

Conclusion: From this activity, we can conclude that yeast reproduces rapidly and produces carbon dioxide during respiration. Bubbles of the gas fill the dough and increase its volume.

Class 8 Science Chapter 2 Microorganisms: Friend And Foe Activity 3

Aim: To carry out the fermentation of sugar.

Materials Required: Beaker, water, sugar, yeast powder, lid, and spoon.

Procedure

  1. Take a 500 mL beaker filled upto 3/4 with water.
  2. Dissolve 2-3 teaspoons of sugar in it.
  3. Add half a spoonful of yeast powder to the sugar solution.
  4. Keep it covered with a lid in a warm place for 4-5 hours.
  5. Smell the solution.

Observation: We will observe a pungent smell

Conclusion: From this activity, we can conclude that sugar has been converted into alcohol by yeast. This process of conversion of sugar into alcohol is known as fermentation.

” Effect Of Yeast On Dough Class 8 “

CBSE Class 8 Science Chapter 2 Microorganisms Friend And Foe Activity’s

CBSE Class 8 Science Chapter 2 Microorganisms Activity With Materials List Activity 4

Aim: To show that microorganisms decompose plant waste.

Materials Required: Pot A and B, soil, plant waste, polythene bag, empty glass bottles, and broken plastic toys.

” Fermentation Process Class 8 “

Procedure:

  1. Take two pots and fill each pot half with soil, and mark them A and B.
  2. Put plant waste in pot A
  3. Put polythene bags, empty glass bottles, and broken plastic toys in pot B.
  4. Put both pots aside. Observe them after 3-4 weeks.

” Decomposition By Microorganisms Class 8 “

Observation: We will observe that the contents of pot A would be converted into manure by the action of the microbes present in the soil. However, there would be no change in the contents of pot B, as microorganisms could not act on the materials present in it

Conclusion: From this activity, we can conclude that microorganisms decompose plant waste and convert it into manure, but they do not act on inorganic substances like polythene bags, plastic toys, etc.

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