Biology

Microbes and Plant Diseases

1,118 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 botany root - external morphology zones of the root morphology of root root system in plants

Hairy root disease of dicot plants is caused by

  1. Agrobacterium tumefaciens

  2. Agrobacterium rhizogene

  3. Bacillus thuringiensis

  4. Meloidogyne incognita
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • A soil bacterium Agrobacterium rhizogenes causes “hairy root” disease in some dicotyledonous plants(For example, capsicum species).
  • A bacterial Ri (root inducing) plasmid integrates its transfer-DNA (T-DNA) into the plant genome (DNA). As a result, rapidly growing and intensely branched (hairy) adventitious roots are developed.
  • Hence Hairy root disease of dicot plants is caused by Agrobacterium rhizogene.
  • So, the correct answer is 'Agrobacterium rhizogene'.
Multiple choice evs developmental journey of seed seed to plants germination of seeds life within the seed

The species of Tilletia responsible for hill bunt or stinking smut of wheat are __________________.

  1. Tilletia caries and T. Foetida

  2. Tilletia caries and T. Barclayana

  3. Tilletia contraversa and T. Caries

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Tilletia caries and T. foetida are the primary fungal species responsible for causing common bunt or stinking smut in wheat.

Multiple choice biology cell biology and biotechnology agritourism biotechnology commercial applications of biotechnology

Natural resistance to late blight of potato is present in

  1. Solanum tuberosum

  2. Solanum acaule

  3. S. demissum

  4. S. stoioniferum
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Complete destruction of the potato crop by late blight caused the 'Irish potato famine' in the middle of the 19th century, led to the search for resistant plants. Single genes for resistance to late blight (R genes) were discovered nearly 100 years ago in S. demissum, a wild potato species indigenous to Mexico.

Multiple choice biology biosystematics species, communities and ecosystems kingdom fungi monera, protista, fungi

Which of the following is an edible fungus? 

  1. Mushroom

  2. Cabbage

  3. Pea

  4. Rhizobium
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Edible mushrooms are fleshy and have edible fruit bodies. They are found either below ground or above ground where they may be picked by hand. Edibility is due to the absence of poisonous effects on humans and desirable taste and aroma.

So, the correct answer is 'So, the correct answer is 'Mushroom'
Multiple choice evs the journey of seeds vegetative propagation and seed dispersal seed dispersal seed dispersal and its methods

Which of the following is a seed borne disease

  1. Bacterial blight of rice

  2. Kharia of paddy

  3. Whiptail of Brassica

  4. All of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Bacterial blight of rice is a seed borne disease which is transmitted to paddy. Seedlings when raised under high humid conditions. This disease is caused by Xanthomonas oryzae.

Multiple choice botany mineral nutrition in plants deficiency diseases and symptoms deficiency symptoms macronutrients and micronutrients

You observed that a plant's younger leaves, not the older ones, are yellowing. You recall that the cause of plant sickness can be diagnosed by which leaves are yellowing.
What is the most likely cause of your plant's blight?

  1. Too much shade

  2. Lack of nitrogen-fixing Rhizobium bacteria

  3. A deficiency in a mobile mineral nutrient.

  4. A deficiency in a non-mobile mineral nutrient.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

If there is a deficiency of mobile nutrients, the symptoms are first seen in the leaves. Mobile and immobile nutrients refer to the transportability of these (K), (Mg), (Cl), (Zn) and (Mo).

So, the correct option is 'A deficiency in a non-mobile mineral nutrient'.

Multiple choice botany indian botanical gardens and herbarium importance of herbarium taxonomic aids taxonomy and systematic botany botanical gardens in india

The common fungicide used in preventing growth of fungus on herbarium specimens is 

  1. Copper sulphate

  2. Lime

  3. Mercuric chloride

  4. Both A and B
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The common fungicide used in preventing growth of fungus on herbarium specimens is mercuric chloride. It is highly toxic compound that volatilizes slightly at ordinary temperature and appreciably at 100 degrees Celsius. Mercuric chloride is corrosive to mucous membranes and used as a topical antiseptic and disinfectant. 

So, the correct option is 'Mercuric chloride'.

Multiple choice zoology asexual reproduction sporulation reproduction in bacteria asexual reproduction in organisms

Penicillium produces

  1. Zoospores

  2. Mitospores

  3. Meiospores

  4. Both B and C
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The species of penicillium multiply by vegetative fragmentation as well as asexual and sexual methods.

Asexual reproduction begins with the formation of asexual motile spores called conidia, which are born on the erect, aerial hyphae called conidiophores. The conidiophores branch multiple times and finally terminate into cylindrical bodies called sterigma. At the time of conidium formation, the nucleus of sterigma divides by mitotic division into two. The terminal portion of sterigma gets separated with one nucleus and is called conidium. When it is fully grown another conidium is formed below the first conidium in succession at the end of sterigma. The spores thus formed are mitospores, which germinate to form genetically identical saprophyte.
In sexual reproduction, the spores or conidium are formed by meiosis from the diploid parent zygote. Ascogonium, a female sex organ and Antheridium, a male sex organ arise on adjacent branches and fuse to form meiospores.
Zoospores are spores with flagella. They are motile spores. They are not produced by Penicillium.
Thus, the correct answer is option D.

Multiple choice botany economic importance of bacteria and fungi fungi: benefits and harmful effects useful and harmful fungi uses of fungi

If all fungi in an environment that perform decomposition were to suddenly die, then which group of organisms should benefit most, due to the fact that their fungal competitors have been removed?

  1. Plants

  2. Protists

  3. Prokaryotes

  4. Animals
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • Prokaryotics will be the next group after fungus that will benefit if all the fungus were to die a sudden death.
  • As the protist group consist of mostly disease causing organisms and plants are one that take the benefit from the decomposed material while animals are the those that feed on organisms from first and second tropic level.
  • Prokaryotes mostly have single celled organisms such as bacteria which help in decomposition of the organic waste left by the higher organisms
  • So, the correct answer is 'Prokaryotes'.