Biology

Microbes and Plant Diseases

1,145 Questions

Microbes and plant diseases examine the role of fungi, bacteria, and viruses in causing infections in plants and humans. Topics cover symbiotic associations like mycorrhiza, fungal structures, and specific agricultural pathogens. Practice these biology questions to master microbiology concepts for upcoming competitive examinations.

Fungal associationsPlant pathogensMicrobial structuresBacterial infections

Microbes and Plant Diseases Questions

Multiple choice

Which of the following statement(s) is/are false? P. Leaf streak disease of maize is caused by Stenocarpella macrospora. Q. Stem rot of potato is caused by Sclerotium rolfsii. R. Athelia arachnoidea causes crater rot in carrot. S. Cercospora brachypus causes noble rot disease in grapes.

  1. P only

  2. P and Q

  3. Q and R

  4. R and S

  5. S only
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

P) Leaf streak disease is caused by the fungus Stenocarpella macrospora in maize. Q) The causing fungal pathogen for stem rot of potato is Sclerotium rolfsii. R) Athelia arachnoidea causes crater rot in carrot. S) Grey rot or noble rot disease is caused by Botrytis cinerea in grapes. Mycosphaerella angulata and Cercospora brachypus cause angular leaf spot in grapes. Hence, only statement S is false.

Multiple choice

Match the fungal diseases in Group-I with causative pathogens in Group-II ||| |---|---| |Group-I |Group-II| |P. Leaf spot of cherries and palms|1. Claviceps purpurea| |Q. Ergot of barley|2. Taphrina deformans| |R. Citrus greasy leaf spot|3. Blueriella sp.| |S. Leaf curl of peach and apricot|4. Drechslera teres| | |5. Mycosphaerella citri|

  1. P - 3, Q - 1, R - 5, S - 2

  2. P - 5, Q - 1, R - 4, S - 2

  3. P - 3, Q - 4, R - 5, S - 2

  4. P - 2, Q - 3, R - 4, S - 1

  5. P - 1, Q - 4, R - 5, S - 3
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Leaf spots of cherries and palms are caused by Blueriella sp. The causative agent for ergot disease in Barley is Claviceps purpurea. Citrus greasy leaf spot is caused by the fungus Mycosphaerella citri. Banana leaf spot is caused by Mycosphaerella musicosa. Taphrina deformans causes leaf curl of peach and apricot. Hence, the correct sequence is P - 3, Q - 1, R - 5, S - 2.

Multiple choice

Match the disease in List-A with causing fungal pathogens in List-B and select the correct answer ||| |---|---| |List-A | List-B| |A. Cottony snow mold of wheat|1. Sclerotium rolfsii| |B. White leaf spot of crucifer|2. Coprinus psychromorbidus| |C. Hull rot of almond|3. Rhizopus sp.| |D. Southern blight of cotton|4. Pseudocercosporella capsellae|

  1. A - 2, B - 4, C - 3, D - 1

  2. A - 3, B - 1, C - 4, D - 2

  3. A - 2, B - 4, C - 1, D - 3

  4. A - 1, B - 3, C - 2, D - 4

  5. A - 2, B - 1, C - 3, D - 4
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Cottony snow mold of wheat is caused by the fungus Coprinus psychromorbidus. White leaf spot of crucifer is caused by Pseudocercosporella capsellae. Hull rot disease of almond is mainly caused by Rhizopus sp. Southern blight of cotton is caused by the fungal pathogen Sclerotium rolfsii. Hence, the sequence A - 2, B - 4, C - 3, D - 1 is correct.

Multiple choice

Identify the true statement (s). P. Aerolate leaf spot in citrus is caused by Altemaria altemata. Q. Scab disease of pear is caused by Venturia pirina and Fusicladium pyrorum. R. The causing fungus for shoestring root rot in grapes is Armillaria mellea.

  1. Only P

  2. Only Q

  3. Only R

  4. P and Q

  5. Q and R
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

P. Aerolate leaf spot in citrus is caused by Rhizoctonia solani. Altemaria altemata cause Albinism and Brown spot diseases in citrus. Q. The causing agents for scab disease of pear are Venturia pirina and Fusicladium pyrorum. R. Armillaria mellea causes shoestring root rot in grapes. Hence, both statements Q and R are true.

Multiple choice

Which of the following statements is/are false? A. Xanthomonas campestris causes leaf blight in carrot. B. The causative agent for bud rot disease of coconut is Erwinia spp. C. Happy disease of grapes is caused by Agrobacterium tumefaciens.

  1. A only

  2. B only

  3. C only

  4. A and B only

  5. B and C only
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

A. Leaf blight of carrot is caused by the bacteria Xanthomonas campestris. B. Bud rot disease of coconut is caused by the bacteria Erwinia spp. C. Happy disease is caused by Xylophilus ampelinus in grapes. Agrobacterium tumefaciens causes crown gall disease in grapes. Hence, the statements B and C both are false.

Multiple choice

The causative bacterial agent(s) of Pierce's disease in grapes is /are P. Xylella fastidiosa Q. Xylophilus ampelinus R. Agrobacterium tumefaciens

  1. Only P

  2. Only Q

  3. Only R

  4. P and Q

  5. Q and R
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In grapes, the Pierce's disease is caused by the bacterial agent Xylella fastidiosa. Happy disease is caused by Xylophilus ampelinus in grapes. Agrobacterium tumefaciens causes crown gall disease in grapes. Hence, only P causes Pierce’s disease in grapes.