Economic Importance of Bacteria Long Answer Biology Class-9 ICSE Selina Publishers Part A

Economic Importance of Bacteria Long Answer Biology Class-9 ICSE Selina Publishers Solutions Chapter-9 Part A. Step By Step ICSE Selina Concise Solutions of Chapter-9 Economic Importance of Bacteria with Exercise-9A including MCQs, Very Short Answer Type, Short Answer Type, Long Answer Type and Structured/Application Questions Solved Visit official Website CISCE for detail information about ICSE Board Class-9.

Economic Importance of Bacteria Exe-9A Long Answer Biology Class-9 ICSE Concise Selina Publishers

Board ICSE
Publications Selina Publication
Subject Biology
Class 9th
Chapter-9 Economic Importance of Bacteria and Fungi
Book Name Concise
Topics Solution of D. Long Answer Type
Academic Session 2023-2024

D. Long Answer Type 

Economic Importance of Bacteria Class-9 Biology Concise Solutions  

Page 95

Question 1.

How do bacteria obtain their nourishment?


Modes of nutrition in bacteria:

  1. Autotrophic bacteria: Able to synthesize their own food
  2. Photoautotrophs: Contain chlorophyll and use light energy for the synthesis of food
  3. Chemoautotrophs: Obtain energy by oxidizing inorganic compounds
  4. Heterotrophic bacteria: Require organic compounds as their main source
  5. Saprophytes: Grow on dead and decaying organic matter
  6. Parasites: Obtain their food from living host on which they grow

Question 2.

Describe any two uses of bacteria in industry.


Uses of bacteria in industry:

  1. Tea curing:Certain bacteria are used to produce different flavours of tea.
  2. Tanning of leather:Tanning of leather is basically brought about by sunlight, but there are a few bacteria which are involved in this process.

Question 3.

What are antibiotics? Name any two examples.


Antibiotics are chemical substances produced by a living organism that kill or stop the growth of disease-causing micro-organisms such as fungi and bacteria.

Examples of antibiotics:

  1. Penicillin
  2. Streptomycin

Question 4.

Briefly describe how nitrogen of the atmosphere is converted to nitrates by leguminous plants.


A special category of soil bacteria (Rhizobium) is found living in small nodules on the roots of leguminous plants. These bacteria pick up free nitrogen from the soil and atmosphere and convert it into soluble nitrates. These nitrates are used by the host plant and also by other plants sown later in the same soil.

Question 5.

State how the nitrates in the soil get converted to nitrogen of the atmosphere.


Denitrifying bacteria in the soil break down nitrates present in the soil to release nitrogen gas which enters the atmosphere. Pseudomonas is an example of denitrifying bacteria.

—  : End of Economic Importance of Bacteria Part (A) D. Long Answer Class-9 ICSE Biology Solutions :–

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