ICAR JRF Plant Science Practice Series Memory Based 2024 (Module 2) (41 – 80 MCQ) 

 

Question No. 41

Which type of pollination involves the transfer of pollen from the anther to the stigma of the same flower?

1. Geitonogamy
2. Autogamy
3. Xenogamy
4. Plasmogamy

Correct Answer:2
Explanation: Autogamy is self-pollination within the same flower. Geitonogamy is between flowers on same plant, xenogamy is cross-pollination, plasmogamy is fusion of protoplasts.

 

 

Question No. 42

A plant infected with a mild strain of virus can protect it from the infection of virulent strain of the same virus. This phenomenon is known as:

1. Antagonism
2. Parasitism
3. Cross protection
4. Allelopathy

Correct Answer:3
Explanation: Cross protection is a phenomenon where prior infection with a mild virus strain protects against a virulent strain of the same virus.

 

 

Question No. 43

Statement (I): The National Dairy Research Institute (NDRI) in Karnal, Haryana, focuses on dairy production, management, and processing research.
Statement (II): The Central Institute of Fisheries Education (CIFE), Mumbai, is not recognized as a Deemed-to-be University under ICAR.

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: (I) is true. (II) is false because CIFE, Mumbai is a Deemed-to-be University under ICAR.

 

 

Question No. 44 
In host plant resistance, the race specific PR proteins are encoded by genes:
(A) RFO1 (B) Rpr1 (C) Cf-2 (D) Yr

Options:

1. (A) and (B)
2. (B) and (C)
3. (C) and (D)
4. (B) and (D)

Correct Answer:4 (or 3 depending on context; but Rpr1 and Yr are race-specific resistance genes)
Explanation: Rpr1 (in Arabidopsis) and Yr (yellow rust resistance in wheat) are race-specific. Cf-2 is also race-specific (tomato). The given answer key often picks (B) and (D).

 

 

Question No. 45 

Assertion (A): Digitally assisted diagnosis (DAD) is one kind of modern telecommunications used in plant disease diagnosis.
Reason (R): Diagnosis becomes fast and accurate; hence DAD is most reliable for first-hand information generation of crop diseases.
Options:

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

Correct Answer:1
Explanation: Both are true, and (R) correctly explains why DAD is valuable (speed and accuracy for first-hand info).

 

 

Question No. 46 

Which statement is generally true regarding Bt cotton hybrids in India?

1. They are primarily used for resistance against sucking pests.
2. They incorporate genes for resistance against bollworm complexes.
3. They originated exclusively from G. barbadense.
4. They have completely eliminated the need for insecticide usage.

Correct Answer:2
Explanation: Bt cotton hybrids express Cry toxins effective against bollworms, not sucking pests. They reduce but do not eliminate insecticide use.

 

 

Question No. 47 

Match the following by-products with their uses:
(A) Bagasse → (II) Fibrous residue used as biofuel or in paper/board manufacturing
(B) Molasses → (IV) Syrupy leftover used to produce ethanol or rum
(C) Press Mud → (I) Filter cake used as soil amendment
(D) Vinasse → (III) Distillery effluent used for biogas or fertilizer

Options:

1. (A)-(III), (B)-(I), (C)-(II), (D)-(IV)
2. (A)-(II), (B)-(IV), (C)-(I), (D)-(III)
3. (A)-(I), (B)-(II), (C)-(III), (D)-(IV)(A)-(IV), (B)-(I), (C)-(II), (D)-(III)

Correct Answer:2

 

 

Question No. 48 

Statement (I): The respiratory chain of bacteria is associated with the cytoplasmic membrane.
Statement (II): The respiratory chain of eukaryotes is present in the nuclear membrane.

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: (I) true: bacterial ETC is in plasma membrane. (II) false: eukaryotic ETC is in inner mitochondrial membrane, not nuclear membrane.

 

 

Question No. 49 

Statement (I): Pearl millet is considered as a drought tolerant crop.
Statement (II): Roots of pearl millet form association with microaerophilic diazotrophic bacteria of genus Azospirillum.

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: Both statements are true. Pearl millet is drought-tolerant and associates with Azospirillum for nitrogen fixation.

 

 

Question No. 50 

Match List-1 with List-2:

(A) Self-Incompatibility (Sporophytic Type) → (III) Pollen rejection mechanism determined by genotype of pollen-producing sporophyte
(B) Synergids → (I) Two specialized cells at micropylar end guiding pollen tube entry
(C) Triple Fusion → (IV) One male gamete fuses with two polar nuclei forming primary endosperm nucleus
(D) Dichogamy (Protandry) → (II) Anthers mature before stigma becomes receptive

Options:

1. (A)-(II), (B)-(I), (C)-(III), (D)-(IV)
2. (A)-(I), (B)-(II), (C)-(IV), (D)-(III)
3. (A)-(I), (B)-(III), (C)-(IV), (D)-(II)
4. (A)-(III), (B)-(I), (C)-(IV), (D)-(II)

Correct Answer:4

 

 

Question No. 51 

Statement (I): In replication of DNA, the leading strand is synthesized continuously in the same direction as the movement of the replication fork, requiring only one initial primer.
Statement (II): In DNA replication, the lagging strand is synthesized discontinuously in the opposite direction to the movement of the replication fork, in short fragments called Okazaki fragments. Each Okazaki fragment requires a new RNA primer.

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: Both statements are correct descriptions of leading and lagging strand synthesis.

 

 

Question No. 52:

Which of the following statements are correct?

(A) Statement A
(B) Statement B
(C) Statement C

Options:

1. (A) and (B) only
2. (B) and (C) only
3. (A) and (C) only
4. (A), (B) and (C) only

Correct Answer:
Explanation: All the given statements (A), (B), and (C) are correct. Hence, the most appropriate answer is option 4.

 

 

Question No. 53 

Match List-1 with List-2:

(A) Onion → (I) Bolting
(B) Cabbage → (III) Bulb to seed method
(C) Maize → (IV) Detasseling
(D) Cotton → (II) Emasculation and dusting

Options:

1. (A)-(III), (B)-(I), (C)-(II), (D)-(IV)
2. (A)-(I), (B)-(III), (C)-(II), (D)-(IV)
3. (A)-(I), (B)-(II), (C)-(IV), (D)-(III)
4. (A)-(III), (B)-(I), (C)-(IV), (D)-(III)

Correct Answer:2 (Onion→Bolting, Cabbage→Bulb to seed, Maize→Detasseling, Cotton→Emasculation & dusting)

 

 

Question No. 54 

Hindrance to self-pollination due to some physical barriers, such as the presence of a thin membrane around the anther, is known as:

1. Herkogamy
2. Dichogamy
3. Chasmogamy
4. Plasmogamy

Correct Answer:1
Explanation: Herkogamy is physical barrier to self-pollination. Dichogamy is temporal separation. Chasmogamy is open pollination.

 

 

Question No. 55:

Which type of glycosidic bond is primarily present in amylose (a component of starch)?

Options:

1. α-(1,4) glycosidic bond
2. α-(1,6) glycosidic bond
3. β-(1,4) glycosidic bond
4. β-(1,3) glycosidic bond

Correct Answer:

Explanation: Amylose is a linear polymer of glucose units linked by α-(1,4) glycosidic bonds. These bonds give it a helical structure. In contrast, α-(1,6) bonds are found at branching points in amylopectin, while β-(1,4) bonds occur in cellulose.

 

 

Question No. 56 

The disease cycle of a plant pathogen comprises various events/stages. Arrange in correct order:
(A) Dissemination, (B) Inoculation, (C) Incubation, (D) Colonization, (E) Penetration

Options:

1. (A), (D), (B), (C), (E)
2. (A), (B), (C), (E), (D)
3. (B), (C), (E), (D), (A)
4. (B), (A), (C), (E), (D)

Correct Answer:3? No, correct order: Inoculation → Penetration → Colonization → Incubation → Dissemination (B → E → D → C → A). Option 3 has B, C, E, D, A (incorrect). Correct answer should be none; but given options, maybe B, E, D, C, A missing. Check standard: Inoculation → Penetration → Colonization → Incubation → Dissemination.

 

 

Question No. 57 
A cross between two breeding lines, one with dark red flowers and one with bright white flowers, produces F1 offspring that flowered light red. When the F1 progeny are selfed, a 1:2:1 ratio of dark red to light red to bright white flowers is observed. What genetic phenomenon is consistent with these results?

1. Complete dominance
2. Incomplete dominance
3. Co-dominance
4. Overdominance

Correct Answer:2
Explanation: 1:2:1 ratio in F2 indicates incomplete dominance (heterozygote is intermediate).

 

 

Question No. 58 

Match List-1 with List-2 (Disease and Year of entry into India):

(A) Downy mildew of grapes → (II) 1910
(B) Bunchy top of banana → (I) 1940
(C) Rice blast → (IV) 1918
(D) Wart of potato → (III) 1953

Options:

1. (A)-(II), (B)-(III), (C)-(II), (D)-(IV)
2. (A)-(II), (B)-(I), (C)-(IV), (D)-(III)
3. (A)-(IV), (B)-(III), (C)-(I), (D)-(II)
4. (A)-(III), (B)-(IV), (C)-(II), (D)-(I)

Correct Answer:2

 

 

Question No. 59 
Bacteria responsible for thermophilic flat sour defect in canned food is:

1. Bacillus polymyxa
2. Bacillus stearothermophilus
3. Lactobacillus bulgaricus
4. Clostridium butyricum

Correct Answer:2
Explanation: Bacillus stearothermophilus (now Geobacillus stearothermophilus) causes flat sour spoilage in canned foods.

 

 

Question No. 60
Identify the correct statements about meiosis:
(A) Homologous chromosome pairing and synapsis during prophase I are critically mediated by the synaptonemal complex.
(B) The reductional division of meiosis I is followed by an equational division in meiosis II, where sister chromatids separate and reduce the chromosome number twice.
(C) Meiosis maintains the specific chromosome number of a species.
(D) Meiosis occurs in the reproductive cells.

Options:

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

Correct Answer:3
Explanation: (B) is false because chromosome number is reduced only once (in meiosis I), not twice.

 

Question No. 61 

Select the correct statements about the ‘Epistasis hypothesis’ of heterosis:
(A) Epistasis is also known as non-allelic interaction.
(B) Heterosis has a positive association with the presence and magnitude of non-allelic interaction.
(C) The non-allelic interactions are of two types only, viz., additive x additive and dominance x dominance.
(D) Epistasis, particularly those that involve dominance x dominance interaction, may contribute to heterosis.

Options:

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

Correct Answer:2 (A, B, D are correct; C is false because epistasis includes additive×additive, dominance×dominance, and additive×dominance)

 

 

Question No. 62 

Statement (I): Viruses can spread by direct transfer of sap from a virus infected plant to a healthy plant.
Statement (II): Insects never transmit viruses in plants.

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: (I) true (mechanical transmission). (II) false: many insects (aphids, leafhoppers) transmit plant viruses.

 

Question No. 63 

Which of the following missions were announced by the Government of India as part of the Union Budget 2025-26?
(A) National Mission on High Yielding Seeds
(B) Mission for Cotton Productivity
(C) Millet Mission
(D) National Mission on Edible Oils

Options:

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

Correct Answer:1 (As per budget announcements)

 

 

Question No. 64 

The black rust of wheat caused by Puccinia graminis tritici. This heteroecious pathogen completes its life cycle by various spore forms. These are:
(A) Basidiospores, (B) Teleutospores/Teliospores, (C) Uredospores, (D) Aecospores, (E) Pycnospores.
Choose the correct spore formation sequence:

1. (C), (B), (A), (E), (D)
2. (B), (C), (A), (E), (D)
3. (A), (B), (C), (E), (D)
4. (A), (D), (B), (C), (E)

Correct Answer:3? Actually sequence: Basidiospores → Pycnospores → Aecospores → Uredospores → Teliospores → Basidiospores. Correct order: (A) → (E) → (D) → (C) → (B) → (A). Option not given clearly.

 

 

Question No. 65 

Match List-1 with List-2 (Institute/Centre and Location):

(A) HCIO and Indian Type Culture Collection (ITCC) → (II) IARI, New Delhi
(B) National Bureau of Plant Genetic Resources (NBPGR) → (III) New Delhi
(C) Central Potato Research Institute (CPRI) → (IV) Shimla, Himachal Pradesh
(D) ICRISAT → (I) Hyderabad

Options:

1. (A)-(II), (B)-(III), (C)-(IV), (D)-(I)
2. (A)-(II), (B)-(I), (C)-(IV), (D)-(III)
3. (A)-(IV), (B)-(III), (C)-(I), (D)-(II)
4. (A)-(III), (B)-(I), (C)-(IV), (D)-(II)

Correct Answer:1

 

Question No. 66:

Common scab of potato is more severe in:

Options:

1. Sandy loam soil
2. Clay loam soil
3. Dry alkaline soil
4. Highly acidic soil

Correct Answer: 3

Explanation: Common scab of potato is caused by Streptomyces scabies and becomes more severe in dry, alkaline soils. Maintaining slightly acidic soil conditions helps in suppressing the disease.

 

 

Question No. 67

The crop(s) affected by smut diseases are:  (A) Wheat (B) Rice (C) Chickpea (D) Sugarcane

Options:

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

Correct Answer:2 (Wheat – loose smut, Rice – false smut, Sugarcane – smut; Chickpea not typically affected by smut)

 

 

Question No. 68 

Which of the following is a by-product of biogas production?

1. Ash
2. Slurry
3. Sawdust
4. Biochar

Correct Answer:2 (Slurry/digestate is the by-product of biogas production; biochar is from pyrolysis)

 

 

Question No. 69

Which of the following tests is primarily used to check the viability of seeds?
(A) Germination test (B) Grow-out Test (C) Accelerated aging test (D) Tetrazolium test

Options:

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

Correct Answer:2 (Germination, accelerated aging, and tetrazolium test viability; grow-out test is for genetic purity)

 

Question No. 70 

Match List-1 with List-2 (Fungicides and Disease control):

(A) Sulphur → (IV) Powdery mildews
(B) Kitazin → (I) Blast of rice
(C) Plantvax → (II) Rust
(D) Ridomil → (III) Late blight of potato

Options:

1. (A)-(II), (B)-(I), (C)-(III), (D)-(IV)
2. (A)-(II), (B)-(I), (C)-(IV), (D)-(III)
3. (A)-(IV), (B)-(I), (C)-(II), (D)-(III)
4. (A)-(III), (B)-(IV), (C)-(II), (D)-(I)

Correct Answer:3

 

Question No. 71

Statement (I): Lignin is the constituent of cell wall that confers structural support, impermeability and resistance against microbial attack.
Statement (II): Lignin is not decomposed by any microorganism.

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.Statement (I) is false but Statement (II) is true.

Correct Answer:3
Explanation: (I) true. (II) false: many fungi (white rot, brown rot) decompose lignin.

 

 

Question No. 72 

Match List-1 with List-2:

(A) Initiation of protein synthesis using N-formylmethionine → (III) Prokaryotic protein synthesis
(B) Presence of spliceosomal introns within protein-coding genes → (I) Eukaryotic genome organization
(C) Cellular respiration sites, primarily located on the inner mitochondrial membrane → (IV) Eukaryotic energy metabolism
(D) Genetic material, typically organized as a single circular DNA molecule in the cytoplasm without a nuclear envelope → (II) Prokaryotic cellular structure

Options:

1. (A)-(III), (B)-(I), (C)-(IV), (D)-(II)
2. (A)-(III), (B)-(IV), (C)-(II), (D)-(I)
3. (A)-(I), (B)-(II), (C)-(IV), (D)-(III)
4. (A)-(III), (B)-(IV), (C)-(I), (D)-(II)

Correct Answer:1

 

 

Question No. 73 

The large vessel containing conditions necessary for the growth of desired microorganisms is called as:

1. Bioreactor
2. Autoreactor
3. Impeller
4. Autoclave

Correct Answer:1
Explanation: Bioreactor (fermenter) is used for large-scale microbial growth.

 

 

Question No. 74:
The sclerotia of Sclerotinia sclerotiorum and Sclerotium rolfsii resemble which of the following, respectively?

(A) Mustard seeds
(B) Irregular black rat droppings
(C) Round brown seeds (mustard-like)
(D) Large, elongated black bodies

Options:

1. (A) and (B), respectively
2. (B) and (C), respectively
3. (B) and (D), respectively
4. (A) and (C), respectively

Correct Answer: 4. 

Explanation: Sclerotinia sclerotiorum produces large, black, irregular sclerotia, often compared to mustard seeds in general appearance, whereas Sclerotium rolfsii produces small, round, brown sclerotia resembling mustard seeds. Hence, option 4 is the most appropriate match.

 

 

Question No. 75:

Assertion (A): Common scab of potato is more severe in alkaline soils.
Reason (R): The pathogen Streptomyces scabies grows better in alkaline soil conditions.

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:

Explanation: Common scab disease is favored by alkaline soil conditions, as Streptomyces scabies thrives in such environments. Acidic soils suppress the pathogen, reducing disease incidence.

 

Question No. 76 

Arrange the following in logical sequence for a farmer registering a traditional variety under the PPVFRA:
(A) Submission of registration form (with minimal fee or fee waiver)
(B) Verification of farmer’s variety claims by the Authority
(C) DUS testing (if necessary/feasible for that variety)
(D) Registration and issuance of certificate

Options:

1. C → B → A → D
2. A → C → D → B
3. A → B → C → D
4. B → A → D → C

Correct Answer:3

 

Question No. 77 
Which of the following examples correctly illustrates the relationship among x, n, and 2n in a tetraploid species?

1. x=5, n=5, 2n=10
2. x=5, n=10, 2n=20
3. x=5, n=20, 2n=40x=10, n=5, 2n=10

Correct Answer: 2
Explanation: In tetraploid, basic number x=5, n=10 (2n=20). n = 2x for tetraploid.

 

Question No. 78:
In a population following Hardy–Weinberg equilibrium, the frequency of allele R (p) is 0.6 and allele r (q) is 0.4. What will be the expected frequency of heterozygous genotype (Rr)?

Options:

1. r frequency = 0.4
2. RR frequency = 0.16
3. Rr frequency = 0.32
4. Rr frequency = 0.48

Correct Answer: 4. 

 

Question No. 79 

Statement (I): Inbreeding depression is most common in cross pollinated crops.
Statement (II): Repeated selfing, though it reduces vigour, is necessary to create genetically stable inbred lines that maximize heterosis in the F1.

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: Both statements are true.

 

Question No. 80 

Which of the following organization established by the Government of India is responsible for the promotion and exports of agricultural and processed food products?

1. NABARD
2. FSSAI
3. APEDA
4. NBPGR

Correct Answer:3 (Agricultural and Processed Food Products Export Development Authority)