ICAR JRF Plant Science Practice Series Memory Based 2024 (Module 1) (41 – 80 MCQ) 

 

Question 41

Match List I with List II (Fungal Structure and Genera):
Options:

1. A-V, B-IV, C-III, D-II, E-I
2. A-I, B-II, C-III, D-IV, E-V
3. A-V, B-IV, C-II, D-III, E-I
4. A-IV, B-V, C-III, D-II, E-I

Correct Answer: 2

Explanation: Fungal structures like conidia, sclerotia, spores, hyphae are characteristic of specific genera, helping in taxonomic identification.

 

 

Question 42

Match List I with List II (Disease and Pathogen):
Options:

1. A-II, B-III, C-V, D-IV, E-I
2. A-III, B-II, C-V, D-IV, E-I
3. A-III, B-II, C-IV, D-V, E-I
4. A-II, B-III, C-IV, D-V, E-I

Correct Answer: 4

Explanation:  Each plant disease is caused by a specific pathogen. Correct matching is essential for diagnosis and selecting control measures.

 

 

Question 43

1. Type I Nonhost resistance does not have visible symptoms
   B. Type II Nonhost resistance is always associated with hypersensitive reaction
   C. Neither Type I nor Type II Nonhost resistance is useful for resistance breeding
   D. Type II Nonhost resistance and Host resistance involve the same signal transduction pathway
   Options:
2. C and E only
3. A and C only
4. D and E only
5. A, B and D only

Correct Answer: 4

• Explanation:
• Type I nonhost resistance → no visible symptoms
• Type II → involves hypersensitive response (HR)
• Type II shares signaling pathways with host resistance, These mechanisms are important in durable disease resistance breeding.

 

 

Question 44

• Assertion A: Complete absence of false negative results would make a diagnostic kit highly successful.
• Reason R: False negatives are due to poor sensitivity of the phenotypic or molecular marker deployed.
  Options:

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is NOT the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Correct Answer: 1

Explanation: False negatives occur when a test fails to detect a pathogen due to low sensitivity of markers or detection tools. A good diagnostic kit must minimize false negatives to ensure accurate disease detection, so reason correctly explains assertion.

 

 

Question 45

• Statement I: Explosive epidemics are caused by foliar pathogens that are clonally reproduced.
• Statement II: Clonal reproduction allows genetically non-identical virulent types.
  Options:

1. Both Statement I and Statement II are correct
2. Both Statement I and Statement II are incorrect
3. Statement I is correct but Statement II is incorrect
4. Statement I is incorrect but Statement II is correct

Correct Answer: 3

Explanation: Explosive epidemics are commonly caused by foliar pathogens (e.g., rusts, mildews) that reproduce clonally, producing large numbers of spores rapidly and spreading quickly. However, clonal reproduction results in genetically identical progeny, not non-identical types. Hence Statement I is correct, but Statement II is incorrect.

 

 

Question 46

• Statement I: PAMPs are coded by highly conserved genetic loci in the pathogen.
• Statement II: PAMPs are perceived by highly conserved plant receptors termed as PRRs.
  Options:

1. Both Statement I and Statement II are correct
2. Both Statement I and Statement II are incorrect
3. Statement I is correct but Statement II is incorrect
4. Statement I is incorrect but Statement II is correct

Correct Answer: 1

Explanation: PAMPs (Pathogen-Associated Molecular Patterns) such as flagellin and chitin are encoded by highly conserved genes in pathogens. Plants recognize them using Pattern Recognition Receptors (PRRs) located on the cell surface, initiating PAMP-triggered immunity (PTI). Thus, both statements are correct.

 

 

Question 47

• Statement I: Mutations in Avr-gene are beneficial for the pathogens.
• Statement II: Mutation in the effector coding gene would improve the perception of effectors by plant cytoplasmic receptor.
  Options:

1. Both Statement I and Statement II are correct
2. Both Statement I and Statement II are incorrect
3. Statement I is correct but Statement II is incorrect
4. Statement I is incorrect but Statement II is correct

Correct Answer: 3

Explanation: Mutations in Avr genes help pathogens evade detection by plant resistance (R) genes, making them advantageous. However, such mutations generally reduce recognition by plant receptors, not improve it. Therefore, Statement I is correct, but Statement II is incorrect.

 

 

Question 48

• Assertion A: Monocropping of genetically identical crop varieties would enable the pathogen to evolve.
• Reason R: Pathogen evolution is rapid in biotrophic interactions.
  Options:

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is NOT the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Correct Answer: 2

Explanation: Monocropping creates a uniform host population, allowing pathogens to adapt and evolve rapidly due to selection pressure. Although biotrophic pathogens evolve quickly, this is not the direct reason for monocropping-driven evolution. Hence both A and R are true, but R is not the correct explanation.

 

 

Question 49

• Statement I: Most economically important plant viruses have only ssRNA as their genetic material.
• Statement II: Viruses with ssDNA as their genetic material cause plant disease epidemics.
  Options:

1. Both Statement I and Statement II are correct
2. Both Statement I and Statement II are incorrect
3. Statement I is correct but Statement II is incorrect
4. Statement I is incorrect but Statement II is correct

Correct Answer: 3

Explanation: Most economically important plant viruses (e.g., TMV, potyviruses) have ssRNA genomes, making Statement I correct. Although ssDNA viruses (e.g., geminiviruses) exist, they are fewer and not the dominant cause of major epidemics, so Statement II is incorrect.

 

 

Question 50

Match List I (Book) with List II (Author)

List I (Book)	List II (Author)
A. The Origin of Species	I. Gregor Mendel
B. Experiments on Plant Hybridization	II. Charles Darwin
C. The Double Helix	III. Barbara McClintock
D. The Genetic Control of Biochemical Reactions in Neurospora	IV. James D. Watson
E. The Mobile Genetic Elements	V. George W. Beadle and Edward L. Tatum

Options:

1. A – II, B – I, C – IV, D – V, E – III
2. A – I, B – II, C – III, D – IV, E – V
3. A – II, B – I, C – III, D – V, E – IV
4. A – III, B – IV, C – V, D – I, E – II

Correct Answer: 1

 

 

Question 51

• Assertion A: Gene for gene interaction can be usually observed in the biotrophic pathosystem.
• Reason R: Biotrophs entirely dependent on their host plant to complete their life cycle.
  Options:

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is NOT the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Correct Answer: 1

Explanation:  Gene-for-gene interaction occurs mainly in biotrophic pathogens, where specific pathogen Avr genes interact with plant R genes. Since biotrophs depend entirely on living host tissue, they evolve precise recognition mechanisms, making the reason correctly explain the assertion.

 

 

Question 52

What was the plant virus group that triggered Tulipomania in Holland during the 17th century?

1. Luteoviridae
2. Potyviridae
3. Caulimoviridae
4. Closteroviridae

Correct Answer: 2

Explanation:  Tulipomania was caused by Tulip breaking virus, a member of Potyviridae, which caused striking color patterns in tulip petals, increasing their market value but also spreading disease.

 

 

Question 53

• Assertion A: Faster global connectivity is one of the reasons for the reemergence of certain plant diseases.
• Reason R: The wheat blast outbreak in Bangladesh was attributed to the host jump from rice to wheat during 2016.
  Options:

1. Both A and R are correct and R is the correct explanation of A.
2. Both A and R are correct and R is the correct explanation of A. (Duplicate option in document)
3. A is correct but R is not correct.
4. A is not correct but R is correct.

 

Correct Answer: 3 

Explanation:  Global connectivity (trade, travel) facilitates rapid movement of pathogens, leading to reemergence of plant diseases. However, the wheat blast outbreak in Bangladesh was not due to a host jump from rice, so the reason is incorrect. Thus A is correct, R is incorrect.

 

 

Question 54

Chloroplasts are present in the cells of:
A. Fungi
B. Algae
C. Plants
D. Animals
Options:

1. A and C only
2. C only
3. B and C only
4. C and D only

Correct Answer: 3

Explanation: Chloroplasts are present in photosynthetic organisms like algae and plants. Fungi and animals lack chloroplasts as they are heterotrophic.

 

 

Question 55

According to latest classification, the Prokaryotes are divided into two domains:

1. Archaea and Bacteria
2. Eubacteria and Bacteria
3. Bacteria and Fungi
4. Archaeobacteria and Actinobacteria

Correct Answer: 1

Explanation: Modern classification divides prokaryotes into two domains: Archaea and Bacteria, based on differences in genetic makeup, membrane lipids, and metabolic pathways.

 

 

Question 56

Match the following:

List I	List II
A. Polymerase Chain Reaction	I. Robert Koch
B. Penicillin	II. Kary Mullis
C. Bacillus anthracis	III. Edward Jenner
D. Pasteurization	IV. Alexander Flemming
E. Smallpox Vaccine	V. Louis Pasteur

Options:

1. A-IV, B-II, C-I, D-V, E-III
2. A-IV, B-II, C-III, D-V, E-I
3. A-II, B-IV, C-I, D-V, E-III
4. A-II, B-IV, C-III, D-V, E-I

Correct Answer: 3

• PCR → Kary Mullis
• Penicillin → Alexander Fleming
• Bacillus anthracis → Robert Koch
• Pasteurization → Louis Pasteur
• Smallpox vaccine → Edward Jenner. These discoveries are foundational in microbiology and biotechnology.

 

 

Question 57

Ribosomes are made up of:
A. RNA
B. Protein
C. Glucose
D. DNA
Options:

1. A and C only
2. A and B only
3. A, B and D only
4. A, B and C only

Correct Answer: 2

Explanation:  Ribosomes are composed of ribosomal RNA (rRNA) and proteins. rRNA forms the structural and catalytic core, while proteins stabilize the structure. DNA and glucose are not components of ribosomes.

 

 

Question 58

Statement I: Diazotrophs possess Nitrogenase enzyme that helps in biological nitrogen fixation.
Statement II: Both Rhizobium and Azotobacter are symbiotic nitrogen fixers.
Options:

1. Both Statement I and Statement II are true
2. Both Statement I and Statement II are false
3. Statement I is true but Statement II is false
4. Statement I is false but Statement II is true

Correct Answer: 3

Explanation:  Diazotrophs possess nitrogenase enzyme for nitrogen fixation (true). However, Rhizobium is symbiotic, while Azotobacter is free-living, not symbiotic. Hence Statement II is false.

 

 

Question 59

Bonds involved in the protein structure are:
A. Peptide bond
B. Hydrogen bond
C. Ionic Bond
D. Disulfide bond
E. Hydrophobic interactions

Options:

1. A and B only
2. A, B and D only
3. A, D and E only
4. A, B, C, D and E

Correct Answer: 4

• Explanation:
• Protein structure is stabilized by multiple bonds:
• Peptide bonds (primary structure)
• Hydrogen bonds (secondary structure)
• Ionic bonds & disulfide bonds (tertiary structure)
• Hydrophobic interactions (folding stability)
  All contribute to protein structure.

 

Question 60

• Assertion A: Outer membrane in Gram negative bacteria is more permeable than the inner membrane.
• Reason R: Porin proteins are present in the outer membrane.
  Options:

1. Both A and R are true and R is the correct explanation of A
2. Both A and R are true but R is NOT the correct explanation of A
3. A is true but R is false
4. A is false but R is true

Correct Answer: 1

Explanation: Gram-negative bacteria have an outer membrane with porins, which allow passage of small molecules, making it more permeable than the inner membrane. Thus, the reason correctly explains the assertion.

 

 

Question 61

Match the following:

List I	List II
A. O antigens	I. Mycorrhizae
B. Teichoic acid	II. Gram Negative Bacteria
C. Pseudomonas	III. Protozoa
D. Pseudomonas (duplicate?)	IV. Archaea
E. Arbuscules	V. Gram Positive bacteria

Options:

1. A-II, B-II, C-IV, D-I, E-V
2. A-IV, B-V, C-II, D-II, E-I
3. A-II, B-IV, C-II, D-I, E-V
4. A-II, B-V, C-IV, D-II, E-I

Correct Answer: 4

• O antigen → Gram-negative bacteria (LPS component)
• Teichoic acid → Gram-positive bacteria
• Pseudomonas → Gram-negative bacteria
• Arbuscules → mycorrhizae. This reflects structural and taxonomic associations.

 

 

Question 62

The subunits of 80S ribosome include:

1. 40S and 50S
2. 40S and 60S
3. 30S and 50S
4. 30S and 60S

Correct Answer: 2

Explanation: Eukaryotic ribosomes (80S) consist of 40S (small subunit) and 60S (large subunit), unlike prokaryotic 70S ribosomes (30S + 50S).

 

 

Question 63

• Assertion A: Mycoplasmas are pleomorphic in shape.
• Reason R: Cell wall in Mycoplasmas is flexible.
  Options:

1. Both A and R are true and R is the correct explanation of A
2. Both A and R are true but R is NOT the correct explanation of A
3. A is true but R is false
4. A is false but R is true

Correct Answer: 3 (Mycoplasmas lack cell wall, so R is false)

Explanation: Mycoplasmas are pleomorphic because they lack a rigid cell wall, not because of flexibility of a wall. Hence the reason is incorrect.

 

 

Question 64

• Assertion A: Archaea are insensitive to chloramphenicol antibiotic.
• Reason R: Archaea do not contain peptidoglycan in the cell wall.
  Options:

1. Both A and R are true and R is the correct explanation of A
2. Both A and R are true but R is NOT the correct explanation of A
3. A is true but R is false
4. A is false but R is true

Correct Answer: 1

 

 

Question 65

• Statement I: Self-replicating, circular, extrachromosomal DNA present in bacteria is known as Plasmid.
• Statement II: Copy number of Plasmid is fixed in a bacterial cell.
  Options:

1. Both Statement I and Statement II are true
2. Both Statement I and Statement II are false
3. Statement I is true but Statement II is false
4. Statement I is false but Statement II is true

Correct Answer: 3

Explanation: Plasmids are self-replicating circular DNA molecules outside the chromosome. Their copy number is not fixed; it varies depending on plasmid type and regulation.

 

Question 66

• Assertion A: Meiosis is a reductional division.
• Reason R: In meiosis, the chromosome number is reduced from diploid to haploid.
  Options:

1. Both A and R are true and R is the correct explanation of A
2. Both A and R are true but R is NOT the correct explanation of A
3. A is true but R is false
4. A is false but R is true

Correct Answer: 1

Explanation: Meiosis is called reductional division because chromosome number is reduced from diploid (2n) to haploid (n) during gamete formation. The reason directly explains the assertion.

 

 

Question 67

• Assertion A: Viruses are termed as obligate intracellular parasites.
• Reason R: Viruses cannot reproduce independently, they can grow only inside a living cell.
  Options:

1. Both A and R are true and R is the correct explanation of A
2. Both A and R are true but R is NOT the correct explanation of A
3. A is true but R is false
4. A is false but R is true

Correct Answer: 1

Explanation: Viruses are obligate intracellular parasites because they lack metabolic machinery and must use host cell systems for replication. Hence the reason correctly explains the assertion.

 

 

Question 68

Which of the following is/are a part of SARS CoV?
A. Presence of Envelope
B. Positive-sense single stranded RNA
C. Spike protein
Options:

1. A and B only
2. A and C only
3. A, B and C only
4. A, B and D only

Correct Answer: 3

SARS-CoV virus has:

• Envelope (lipid membrane)
• Positive-sense ssRNA genome
• Spike proteins for host attachment
  All three are correct structural components.

 

Question 69

Match the Following:

List I	List II
A. Pasteurization	I. Fractional Sterilization
B. Tyndallization	II. Foul smell due to anaerobic decomposition of proteins
C. Radiation sterilization	III. Extends shelf life of Milk
D. Incineration	IV. Heat sensitive material
E. Putrefaction	V. Inoculation loops and needles

Options:

1. A-I, B-IV, C-III, D-V, E-II
2. A-III, B-II, C-IV, D-V, E-I
3. A-III, B-I, C-IV, D-V, E-II
4. A-IV, B-II, C-III, D-V, E-I

Correct Answer: 3

• Explanation:
• Pasteurization → extends milk shelf life
• Tyndallization → fractional sterilization
• Radiation → used for heat-sensitive materials
• Incineration → used for loops/needles
• Putrefaction → anaerobic decomposition causing foul smell

 

 

Question 70

A bacteriophage genome integrated into the circular bacterial chromosome is known as:

1. Prophage
2. Metaphage
3. Baphage
4. Prophase

Correct Answer: 1

Explanation: A bacteriophage genome integrated into host DNA is called a prophage, seen in lysogenic cycles.

 

 

Question 71

Statement I: According to Koch’s Postulates, inoculation with disease causing microorganism must be able to produce disease symptoms in the susceptible host.
Statement II: According to Koch’s Postulates, the microorganism must be recoverable from the diseased host.
Options:

1. Both Statement I and Statement II are true
2. Both Statement I and Statement II are false
3. Statement I is true but Statement II is false
4. Statement I is false but Statement II is true

Correct Answer: 1

• Explanation:
• Koch’s postulates require:
• Pathogen must cause disease in a healthy host
• Pathogen must be re-isolated from infected host
  Both statements correctly describe these criteria.

 

Question 72

Match the following:

List I	List II
A. Central Island Agricultural Research Institute	I. Ludhiana, Punjab
B. Central Research Institute for Dryland Agriculture	II. Baramati, Maharashtra
C. Central Institute of Post-Harvest Engineering and Technology	III. Port Blair, Andaman & Nicobar
D. National Institute of Abiotic Stress Management	IV. Indore, Madhya Pradesh
E. Indian Institute of Soybean Research	V. Hyderabad, Telangana

Options:

1. A-III, B-V, C-I, D-III, E-IV
2. A-III, B-IV, C-IV, D-III, E-IV
3. A-III, B-V, C-IV, D-III, E-I
4. A-III, B-IV, C-III, D-I, E-V

Correct Answer: 1

• CIARI → Port Blair
• CRIDA → Hyderabad
• CIPHET → Ludhiana
• NIASM → Baramati
• IISR → Indore These are important ICAR institutes across India.

 

 

Question 73

Ukraine-Russia war has majorly impacted the price of which crop globally?

1. Rice
2. Wheat
3. Cotton
4. Pearl millet

Correct Answer: 2

Explanation: Ukraine and Russia are major exporters of wheat, so the war disrupted supply chains, causing global price increases.

 

 

Question 74

• Statement I: In Rhizobium-legume symbiosis, large and pink colored nodules are considered good for efficient nitrogen fixation.
• Statement II: Pink color of the nodules is due to the presence of leg-haemoglobin pigment.
  Options:

1. Both Statement I and Statement II are true
2. Both Statement I and Statement II are false
3. Statement I is true but Statement II is false
4. Statement I is false but Statement II is true

Correct Answer: 1

Explanation: In Rhizobium–legume symbiosis, effective nodules are large and pink, indicating active nitrogen fixation. The pink color is due to leghemoglobin, an oxygen-binding pigment that maintains low oxygen concentration to protect nitrogenase while still allowing respiration. Thus, both statements are correct.

 

 

Question 75

The year 2023 has been declared as ‘International Year of …’

1. Cereals
2. Pulses
3. Millets
4. Oil seeds

Correct Answer: 3

Explanation: The International Year of Millets (2023) was declared to highlight millets as nutri-cereals rich in fiber, minerals, and vitamins. They are also climate-resilient crops, tolerant to drought and poor soils, making them important for food security and sustainable agriculture, especially in semi-arid regions.

 

 

Question 76

Match the Indian Agricultural Revolutions with the related commodities:

List I	List II
A. Blue revolution	I. Milk
B. White revolution	II. Egg/Poultry
C. Yellow revolution	III. Food Grains
D. Green revolution	IV. Oil Seeds
E. Silver revolution	V. Fisheries

Options:

1. A-III, B-I, C-IV, D-III, E-V
2. A-V, B-I, C-IV, D-III, E-II
3. A-III, B-V, C-IV, D-III, E-I
4. A-V, B-II, C-IV, D-III, E-I

Correct Answer: 2

Agricultural revolutions in India represent focused production increases:

• Explanation:
• Blue revolution → expansion of fisheries and aquaculture
• White revolution → milk production (Operation Flood, cooperative model)
• Yellow revolution → oilseed production (self-sufficiency in edible oils)
• Green revolution → high-yielding varieties of wheat and rice
• Silver revolution → poultry and egg production
  These revolutions significantly improved food supply and rural economy.

 

 

Question 77

Flag leaf clipping in hybrid seed production in rice is a regular practice. It is done to achieve:

1. Higher seed set due to better pollination
2. Synchronization of flowering
3. Adjustment of plant height of parental lines
4. Better seed quality

Correct Answer: 1

Explanation: Flag leaf clipping removes the top leaf that may obstruct pollen movement. This enhances air circulation and pollen dispersal, improving cross-pollination efficiency and ultimately increasing seed set in hybrid seed production.

 

 

Question 78

The maximum permissible limit of husk-less seeds in sunflowers is:

1. 0% (by wt.)
2. 0% (by wt.)
3. 0% (by no.)
4. Two per kg

Correct Answer: 3

Explanation: In sunflower seed certification, husk-less seeds are counted numerically (2%) because their presence affects genetic purity and seed integrity. Counting ensures better accuracy than weight-based estimation.

 

 

Question 79

For a crop having a maximum permissible limit for off-types 0.2%, the minimum number of plants required for conducting the GOT is:

1. 800
2. 1600
3. 2000
4. 2400

Correct Answer: 4

Explanation: To detect a very low off-type level (0.2%), a large sample size (2400 plants) is statistically required. Larger samples increase the probability of detecting rare contaminants, ensuring reliability of the Grow-Out Test.

 

 

Question 80

The recommended method for testing the seed germination in mustard is:

1. Sand method
2. Top of paper method
3. Between paper method
4. Wet cloth method

Correct Answer: 3

Explanation: The between paper method provides controlled moisture, aeration, and uniform conditions for small seeds like mustard. It ensures accurate and reproducible germination results, avoiding fungal growth or uneven moisture.