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GSEB Solutions for Class 8 Science and Technology – Microbes

GSEB Solutions for Class 8 Science and Technology – Microbes (English Medium)

GSEB SolutionsMathsScience
Exercise 24:

Solution 1(a):

Name of the Disease Causes Symptoms Precautions Is any microorganism responsible for that? If yes, then which one?
Measles Air High temperature, Sore eyes, dry cough Vaccination at proper age Yes, virus
Hepatitis A Water Fatigue, urea, dark urine Drinking boiled water, vaccination at proper age Yes, virus
Typhoid Water Poor appetite, lethargy, diarrhoea Drinking purified water, vaccination Yes, bacteria

(Salmonella typhii)
Malaria Mosquito bite Fever, Chill, Fatigue Applying mosquito repellants, mosquito nets and proper dosage of medicines Yes, protozoa
Polio Air/ Water Fever, Sore throat, Vomiting, Fatigue Proper vaccination Yes, Virus (Poliomyelitis)
Tuberculosis Air Bad cough for three weeks, weight loss, no appetite, chills Vaccination of BCG Yes, bacteria (Mycobacterium)
Chickenpox Air/ Contact High temperature, loss of appetite, spots in the body leading to itching Antibiotics and proper vaccination Yes, Virus

 

Exercise 30:

Solution 1:

The microorganism is a living organism that requires a microscope to be observed as it cannot be seen with naked eyes.
The types of microorganism are bacteria, virus, fungi, algae, protozoa and fungi.

Solution 2:

The algae is different from other plants in the following ways:

  1. Most algae are single celled.
  2. They are motile by using their cilia or flagella.
  3. They do not have true roots, shoots or veins.
  4.  Algae engage all the water and nutrients they need.

Solution 3:

There are two main types of fungi – yeast and mould.

Solution 4:

The two diseases caused by bacteria are cholera and tuberculosis.

Solution 5:

The two diseases caused by virus are polio and chickenpox.

Solution 6:

Algae prefer moist places like ponds, sewages, reservoirs, rivers, swamps, lakes, and mud. They also grow on marine animals like alligators, worms and aquatic plants.

Solution 7:

There are three types of colours found in algae – brown algae, blue-green algae and red algae.
Brown algae are found near coral reefs, blue-green algae are found in freshwater lakes, streams and ponds, red algae can be found anywhere on the earth ranging from the tropical region to the polar region.

Solution 8:

The reserved food material of the fungi is on dead materials like roti, pickles, wet clothes and leather goods.

Solution 9:

Amoebic dysentery is caused by protozoan, Entamoeba histolytica

Solution 10:

An amoeba has no definite shape. It can move anywhere with the help of cilia and flagella.

Solution 11:

Paramoecium has the definite shape of a slipper (shoe) and moves with the help of cilia.

Solution 12:

Virus is called the connecting link between living and non-living because it possesses both living and non-living characteristics. The living characteristics are as follows –

  1. They can reproduce.
  2. They contain genetic matter.
  3. They are also locomotive.
    The non-living characteristics are as follows –
  1. They cannot replicate alone.
  2. They remain inactive and behave as non-living.

Solution 13:

Most microorganisms are beneficial, for example, there are microorganisms in our large intestine that synthesize vitamins and allow them to be absorbed into the bloodstream. However, a tiny minority are pathogens (disease-causing agents). These pathogens, often called germs or bugs, are a threat to all life forms.

Solution 14:

he virus in tobacco is Tobacco Mosaic Virus (TMV)