Tag: useful and harmful bacteria

Questions Related to useful and harmful bacteria

Citrus canker is caused by

  1. Bacteria

  2. Virus

  3. Fungus

  4. Alga


Correct Option: A
Explanation:

Citrus canker is a disease that is caused by the bacterium Xanthomonas axonopodis. It affects the Citrus species of fruits such as lime, oranges, grapefruit. It results in the lesions on the leaves, stems, fruit and other parts of the citrus plants.

Thus, the correct answer is 'Bacteria.' 

Match items of column I with those of column II and choose the correct combinations.

Column I Column II
a Pneumonia p Vibrio comma
b Citrus Canker q Mycobacterium leprae
c Cholera r Yersinia pestis
d Leprosy s Xanthomonas citri
t Diplococcus pneumoniae
  1. a-t, b-s, c-p, d-q

  2. a-t, b-q, c-s, d-q

  3. a-t, b-s, c-q, d-p

  4. a-t, b-q, c-p, d-s


Correct Option: A
Explanation:

  • Pneumonia is a serious disease caused by Diplococcus pneumoniae. It affects the lungs.
  • Citrus canker disease is caused by bacterium Xanthomonas axonopodis. It affects citrus species like sweet lime, lemon.
  • Cholera is caused by Vibrio cholerae. It results in the severe watery diarrhea.
  • Leprosy is a serious disease caused by Mycobacterium leprae. It affects the skin, nervous system, mucosal surfaces of the upper respiratory tract and the eyes.
Thus, the correct answer is 'a-t, b-s, c-p, d-q.'

Application of penicillin on bacterial cell inhibits the synthesis of 

  1. DNA

  2. RNA

  3. Cell wall

  4. Protein


Correct Option: C
Explanation:

The antibiotics are the chemical substances produced by the natural metabolic processes of bacteria and fungi as their natural defense against other microorganisms. Penicillin is an antibiotic that target the peptide cross-links in the peptidoglycan and disrupt the cell wall integrity. Exposure of penicillin to bacteria stops the cell wall synthesis by inhibition of formation of peptide linkage and bacteria become protoplast (a fragile cell bounded only by a membrane) which is highly susceptible to lysis.  Thus, the correct answer is option C.

Natural decomposition of dead remains of animal, is largely, carried out by 

  1. Prion

  2. Fungi

  3. Viruses

  4. Algae


Correct Option: B

Wide spread use of chemicals in agriculture and industry has

  1. Heath impacts

  2. Polluted the environment

  3. Less fertility of soil

  4. Air pollution


Correct Option: B

Which among the following is a bacterial disease?

  1. Rust of Tea

  2. Red rot of Sugarcane

  3. Citrus canker

  4. Late blight of Potato


Correct Option: C
Explanation:

Rust of Tea is also called as red rust disease. It is caused by algae Cephaleuros parasiticus Karst. It affects the tea plant. Red rot is a disease that affects the sugarcane plant. It is caused by fungus Glomerella tucumanensis. Citrus canker is a bacterial disease affecting Citrus species caused by the Xanthomonas axonopodis. It affects Citrus species like lime, orange. Late blight is an infection caused by fungus Phytophthora infestans. It affects potato and tomato.

Thus, the correct answer is 'Citrus canker.'

VFDF is produced by

  1. Lingbya

  2. Microcystis

  3. Aulosira

  4. Tolypothrix


Correct Option: A
Explanation:

VFDF is also called as Very Fast Death Factor. It is an anatoxin produced by a cyanobacteria, Lingbya. It is a neurotoxin. It causes severe overstimulation of respiratory muscles. This ultimately can result in death.

Thus, the correct answer 'Lingbya.'

Match the lists.

I II
(a) Syphilis (i) Acetobacter
(b) Pathogen of cattle (ii) Agrobacterium
(c) Crown gall of apple (iii) Corynebacterium
(d) Diphtheria (iv) Mycobacterium
(v) Treponema
  1. a-(iii), b-(i), c-(iv), d-(ii)

  2. a-(v), b-(iv), c-(ii), d-(iii)

  3. a-(v), b-(iii), c-(ii), d-(i)

  4. a-(ii), b-(iv), c-(v), d-(iii)


Correct Option: B

A plant disease which is not caused by a fungus is

  1. Red rot of Sugarcane

  2. Late blight of Potato

  3. Black rot of crucifers

  4. Brown rust of wheat


Correct Option: C
Explanation:

Red rot disease is caused by the fungus Glomerella tucumanensis. It produces a structure called as acervuli. This results in profuse sporulation. Late blight of Potato is caused by fungus Phytophthora infestans. It infects and destroys the leaves, stems, fruits, tubers of potato and tomato plants. Black rot of crucifers is caused by bacterium Xanthomonas campestris. It results in dark brown discoloration of the leaves of fruit and vegetables. Wheat leaf rust is a disease caused by fungus Puccinia triticina. It affects wheat, barley and rye stems, leaves and grains. 

Thus, the correct answer is 'Black rot of crucifers.'