ICAR JRF Plant Science Practice Series Memory Based 2024 (Module 1) (81 – 120 MCQ) 

 

Question 81

Restorer gene is located in:

1. Nucleus
2. Cytoplasm
3. Both nucleus and cytoplasm
4. Mitochondria

Correct Answer: 1

Explanation:

• Restorer genes (Rf genes)– Nuclear genes that restore fertility in plants with cytoplasmic male sterility (CMS) .
• They are located in the nucleusand counteract the mitochondrial CMS factors.
• Cytoplasm, mitochondria– CMS factors are located here.

 

 

Question 82

Southern corn blight epidemic of maize was due to susceptibility of:

1. T-cytoplasm
2. A-cytoplasm
3. HT-cytoplasm
4. D-cytoplasm

Correct Answer: 1

Explanation: This is a repeat of Question 7. The Southern corn leaf blight epidemic (1970) was caused by T-cytoplasm(Texas male-sterile cytoplasm) susceptibility to Bipolaris maydis race T.

 

 

Question 83

Source of rust resistance gene in wheat is:

1. Triticum monococcum
2. Aegilops speltoides
3. Triticum timopheevi
4. Triticum durum

Correct Answer: 3

Explanation: This is a repeat of Question 8. Triticum timopheeviis a source of rust resistance genes (e.g., Sr36, Lr18) in wheat.

 

 

Question 84

Indian Journal of Agricultural Science is published by:

1. UPCA
2. ICAR
3. CISR
4. NBR1

Correct Answer: 2

 

Explanation:

• The Indian Journal of Agricultural Sciences (IJAS)is published by the Indian Council of Agricultural Research (ICAR) .
• UPCA– Not a publisher.
• CISR– Not a publisher.
• NBR1– Not a publisher.

 

 

Question 85

Most important organelle during germination which is characteristic of plant cell in oil seeds:

1. Peroxisomes
2. Dictyosomes
3. Spherosomes
4. Glyoxysomes

Correct Answer: 4

Explanation:

• Glyoxysomes– Specialized peroxisomes found in oilseeds (e.g., castor, sunflower). They contain enzymes of the glyoxylate cycle (isocitrate lyase, malate synthase) that convert stored lipids into carbohydrates during germination.
• Peroxisomes– General function in photorespiration and fatty acid oxidation.
• Dictyosomes– Golgi apparatus.
• Spherosomes– Lipid storage organelles.

 

 

Question 86

Which one of the following micro-organism is associated with phosphorus solubilisation?

1. Clostridium
2. Rhizobium
3. Blue green algae
4. VAM fungi

Correct Answer: 4

Explanation:

• VAM (Vesicular Arbuscular Mycorrhizal) fungi– Symbiotic fungi that help in phosphorus solubilization and uptake from the soil.
• Clostridium– Nitrogen fixation (free-living, anaerobic).
• Rhizobium– Symbiotic nitrogen fixation.
• Blue green algae (cyanobacteria)– Nitrogen fixation, not primarily phosphorus solubilization.

 

 

Question 87

When the pH of a solution is decreased one unit from 5 to 4, the [H⁺] ion concentration will:

1. Increase
2. Decrease
3. No change
4. None of these

Correct Answer: 1

Explanation:

• pH is the negative logarithm of hydrogen ion concentration: pH = -log₁₀[H⁺].
• Decreasing pH by 1 unit (5 to 4) means [H⁺] increases 10 times.
• Example: pH 5 → [H⁺] = 10⁻⁵ M; pH 4 → [H⁺] = 10⁻⁴ M (10 times higher).

 

 

Question 88

Minimum support prices for various crops are recommended by:

1. ICAR
2. Commission for Agriculture Cost and Prices
3. Ministry of Commerce and Industry
4. Forward Market cost and price Commission

Correct Answer: 2

Explanation:

• Commission for Agricultural Costs and Prices (CACP)– The government body that recommends Minimum Support Prices (MSP) for various crops in India.
• ICAR– Agricultural research body.
• Ministry of Commerce and Industry– Handles trade, exports, etc.
• Forward Market Commission– Regulates commodity futures.

 

 

Question 89

Land races are:

1. Advanced strains
2. Hybrid varieties
3. Local varieties
4. All of these

Correct Answer: 3

Explanation:

• Land races– Local varieties of crops developed by farmers over generations through selection and adaptation to local environments. They are genetically diverse and often possess stress tolerance.
• Advanced strains– Modern improved varieties.
• Hybrid varieties– First-generation crosses.

 

 

Question 90

In India, normally how many generation system seed are produced?

1. 1
2. 2
3. 3
4. 4

Correct Answer: 4

Explanation:

• In India, the seed multiplication system follows a 4-generation system:
  1. Nucleus seed
  2. Breeder seed
  3. Foundation seed
  4. Certified seed
• Option 4– Correct.

 

 

Question 91

Liquid N₂ has a temperature:

1. −196°C
2. −186°C
3. −176°C
4. −172°C

Correct Answer: 1

Explanation:

• Liquid nitrogen (LN₂)has a boiling point of −196°C at atmospheric pressure.
• It is widely used for cryopreservationof biological samples (semen, embryos, meristems, etc.).
• −186°C– Boiling point of liquid oxygen.
• −176°C, −172°C– Not correct.

 

 

Question 92

Microbe involved in fibre retting:

1. Micrococcus
2. Bacillus subtilis
3. Clostridium butyricum
4. Lactobacillus

Correct Answer: 3

Explanation:

• Fibre retting– A microbial process that separates bast fibres (jute, flax, hemp) from the stem by degrading pectin.
• Clostridium butyricum– An anaerobic bacterium involved in retting (produces pectinolytic enzymes).
• Bacillus subtilis– Aerobic, involved in some retting but less common.
• Micrococcus, Lactobacillus– Not primary retting agents.

 

 

Question 93

Barrier isolation is permitted in seed production of:

1. Rice
2. Hybrid rice
3. Sunflower
4. Castor

Correct Answer: 2

Explanation:

• Barrier isolation– Using physical barriers (e.g., nets, bags, or other crops) to prevent cross-pollination when spatial isolation is not possible.
• It is permitted in hybrid rice seed productionunder certain conditions (e.g., using nylon nets or by planting tall barrier crops like maize or sorghum).
• Rice, sunflower, castor– Typically require spatial isolation, not barrier isolation.

 

 

Question 94

Nipping in bajra hybrid seed production is generally carried out:

1. To enhance tillering capacity
2. To achieve synchrony of flowering
3. To enhance seed quality
4. None of these

Correct Answer: 2

Explanation:

• Nipping– Removal of the apical meristem (shoot tip) at an early stage.
• In bajra (pearl millet) hybrid seed production, nipping is done to achieve synchrony of floweringbetween the male sterile (A-line) and restorer (R-line) parents.
• It also promotes tillering and increases seed yield, but the primary purpose is flowering synchronization.

 

 

Question 95

In three line method of certified seed production, if male parent flowers come earlier than female parent, which parent has to be sown first?

1. A-Line
2. B-Line
3. R-Line
4. A and B line

Correct Answer: 1

Explanation:

• In the three-line system(CMS system):
  • A-line– Male sterile (female parent)
  • B-line– Maintainer line (isogenic fertile)
  • R-line– Restorer line (male parent)
• If the male parent (R-line) flowers earlierthan the female parent (A-line), the female parent (A-line) should be sown first to delay its flowering and achieve synchronization.
• B-line– Not used in hybrid seed production plot.

 

 

Question 96

The maximum area (ha) that can be offered for seed certification is:

1. 5
2. 10
3. 15
4. 25

Correct Answer: 2

Explanation:

• As per Indian Minimum Seed Certification Standards, the maximum area that can be offered for seed certificationin a single lot is 10 hectares for most field crops.
• For certain crops (e.g., rice, wheat, maize), larger areas may be permitted under specific conditions, but the standard maximum is 10 ha.

 

 

Question 97

Hygroscopic equilibrium curves is also called as:

1. Absorption isotherms
2. Adsorption isotherms
3. Absorption isobars
4. Adsorption isobars

Correct Answer: 2

Explanation:

• Hygroscopic equilibrium curves– Also called adsorption isotherms, which describe the relationship between seed moisture content and relative humidity at constant temperature.
• These curves help determine safe storage conditions for seeds.
• Absorption– Uptake of moisture into bulk.
• Isobars– Constant pressure (not relevant here).

 

 

Question 98

Development of sporophyte without fertilization from the vegetative cells of gametophyte is called:

1. Zygospory
2. Aplenospory
3. Apospory
4. Apogamy

Correct Answer: 4

Explanation:

• Apogamy– Development of a sporophyte from the gametophyte without fertilization, using vegetative cells of the gametophyte (not the egg).
• Apospory– Development of a gametophyte from sporophyte cells without meiosis.
• Zygospory– Formation of zygospore.
• Aplenospory– Not a standard term.

 

 

Question 99

Tarai development corporation was established under world bank assistance in:

1. 1969
2. 1970
3. 1971
4. 1973

Correct Answer: 1

Explanation:

• The Tarai Development Corporationwas established in 1969 with World Bank assistance for agricultural development in the Tarai region of Uttar Pradesh.
• It focused on land reclamation, irrigation, and agricultural inputs.

 

 

Question 100

The outermost wall of the ovary is called:

1. Pericarp
2. Perisperm
3. Fruit wall
4. Perianth

Correct Answer: 1

Explanation:

• Pericarp– The wall of the fruit, developed from the ovary wall. It consists of three layers: exocarp, mesocarp, and endocarp.
• Perisperm– Nucellar tissue in some seeds.
• Fruit wall– Another term for pericarp (synonymous).
• Perianth– Collective term for calyx and corolla (floral parts).

 

 

Question 101

The term Scutellum refers to:

1. Residual nucellus of pepper seeds
2. Single cotyledon of cereals
3. Outgrowth of pulse seeds
4. Aril of castor

Correct Answer: 2

Explanation:

• Scutellum– The single cotyledon of cereal grains (e.g., wheat, rice, maize). It absorbs nutrients from the endosperm during germination.
• Residual nucellus– Perisperm.
• Outgrowth of pulse seeds– Not scutellum.
• Aril of castor– A fleshy outgrowth covering the seed.

 

 

Question 102

The plants developed the mechanism to disperse their own seeds by blastically is referred to:

1. Autochory
2. Holochory
3. Anemochory
4. Entomochory

Correct Answer: 1

Explanation:

• Autochory– Seed dispersal by mechanical means (explosive or ballistic mechanism) of the plant itself (e.g., balsam, peas, castor).
• Holochory– Not a standard term.
• Anemochory– Wind dispersal.
• Entomochory– Insect dispersal.

 

 

Question 103

Nomograph is useful to predict:

1. Germination percentage
2. Seed vigour
3. Seed storage pest
4. None of these

Correct Answer: 1

Explanation:

• Nomograph– A graphical tool used in seed science to predict germination percentage based on seed moisture content and storage temperature (using the seed viability equation).
• It is not directly used for seed vigour, pest prediction, or other parameters.

 

 

Question 104

For which system of seed production the grow out test is a prerequisite for grant of certificate?

1. CGMS system
2. GMS system
3. CMS system
4. CHAs system

Correct Answer: 3

Explanation:

• CMS (Cytoplasmic Male Sterility) system– In hybrid seed production, a Grow Out Test (GOT) is mandatory for certification to check the genetic purity of the hybrid seed.
• GMS (Genetic Male Sterility)– Also requires GOT, but the question asks for which system it is a prerequisite (CMS is the classic example).
• CGMS (CMS with nuclear restorer)– Same as CMS.
• CHAs (Chemical Hybridizing Agents)– Also requires GOT.

 

 

Question 105

A variety that has to be registered under plant variety protection act is referred to as:

1. Extinct varieties
2. Candidate varieties
3. Example varieties
4. Reference varieties

Correct Answer: 2

Explanation:

• Candidate variety– A variety submitted for registration under the Protection of Plant Varieties and Farmers’ Rights (PPV&FR) Act, 2001.
• Extinct varieties– Varieties no longer cultivated.
• Example varieties– Used as references for DUS testing.
• Reference varieties– Standard check varieties.

 

 

Question 106

Seed dormancy due to the factors outside the embryo is:

1. Exogenous dormancy
2. Endogenous dormancy
3. Eco-endodormancy
4. Conditioned dormancy

Correct Answer: 1

Explanation:

• Exogenous dormancy– Caused by factors outside the embryo, such as hard seed coat (physical dormancy) or germination inhibitors in the seed coat or endosperm.
• Endogenous dormancy– Caused by factors within the embryo (morphological or physiological dormancy).
• Eco-endodormancy– Combined exogenous and endogenous.
• Conditioned dormancy– Not a standard term.

 

 

Question 107

In certified class seed production of three line system, which line is used in border row?

1. A line
2. B line
3. R line
4. Pollinated variety

Correct Answer: 3

Explanation:

• In three-line systemhybrid seed production, the border rows are planted with the R line (restorer line/male parent) to provide adequate pollen to the A-line (male sterile female) in the main plot.
• This ensures good seed set on the A-line.
• A line, B line, pollinated variety– Not used in border rows.

 

 

Question 108

Ninety per cent of global cotton production covers under species of:

1. arboreum
2. hirsutum
3. barbadense
4. herbaceum

Correct Answer: 2

Explanation:

• Gossypium hirsutum(Upland cotton) accounts for approximately 90% of global cotton production.
• barbadense– Egyptian cotton (about 5-8%).
• arboreumand G. herbaceum – Old World diploid cottons (minor production).

 

 

Question 109

The name of the chemical, which on spraying will enhance complete panicle exertion in hybrid seed production of rice:

1. Glutamic acid
2. Ethanol
3. Lactic acid
4. Gibberellic acid

Correct Answer: 4

Explanation:

• Gibberellic acid (GA₃)– Sprayed on rice panicles to enhance panicle exertion (emergence) from the flag leaf sheath, which is critical in hybrid seed production (especially for CMS lines where panicle exertion is poor).
• Glutamic acid, ethanol, lactic acid– Not used for this purpose.

 

 

Question 110

Genetic purity in the field is controlled through:

1. Seed testing
2. Seed sampling
3. Field inspection
4. Rouging

Correct Answer: 4

Explanation:

• Rouging– Removal of off-type plants (unwanted variants) from the seed production field before they contaminate the seed lot. It is the primary method to maintain genetic purity in the field.
• Seed testing– Done in the laboratory.
• Seed sampling– For collecting samples.
• Field inspection– To monitor but not directly control purity (rouging is the action).

 

 

Question 111

Hypo-epigeal germination is seen in:

1. Groundnut
2. Peperomia peruviana

Correct Answer: 1

Explanation:

• Hypo-epigeal germination– A type of germination where the cotyledons are initially hypogeal (below ground) but later become epigeal (above ground). It is seen in groundnut (peanut) . The cotyledons remain underground during early growth but may be pushed above ground later.
• Peperomia peruviana– Shows other types of germination.

 

 

Question 112

Palaeontology deals with:

1. Study of seed
2. Study of flower
3. Study of pollen
4. Study of pistil

Correct Answer: 3

Explanation:

• Palaeontology– The study of pollen grains and spores (especially fossil pollen). It is used in palynology, a branch of palaeontology.
• Study of seed– Spermology.
• Study of flower– Anthology.
• Study of pistil– Not a specific field.

 

 

Question 113

Electrophoresis is a test useful for:

1. Differentiating varieties
2. High and low vigour seeds
3. Viable and non-viable seeds
4. Dormant seeds

Correct Answer: 1

Explanation:

• Electrophoresis– A technique used to separate proteins or DNA based on size and charge. In seed science, it is used for varietal identification and differentiation (e.g., protein electrophoresis for distinguishing crop varieties).
• It is not typically used for vigour, viability, or dormancy testing.

 

 

Question 114

The seed control order deals with:

1. Certification
2. Seed testing
3. Licensing for sale of seed
4. Notification

Correct Answer: 3

Explanation:

• Seed Control Order (SCO)– A regulatory order under the Essential Commodities Act that governs the licensing of seed sellers, quality control, and regulation of seed trade.
• Certification– Under Seeds Act, 1966.
• Seed testing– Part of quality control.
• Notification– Variety release and notification.

 

 

Question 115

The cross pollination of bajra favors by:

1. Self incompatibility
2. Protogyny
3. Protoandry
4. Heterostyly

Correct Answer: 2

Explanation:

• Pearl millet (bajra)– A cross-pollinated crop that exhibits protogyny (stigma matures before anthers) to promote outcrossing.
• Self incompatibility– Not common in bajra.
• Protoandry– Anthers mature first (e.g., in maize).
• Heterostyly– Different style lengths (e.g., in linseed).

 

 

Question 116

Prolonged rouging operation will not affect the genetic purity in case of:

1. Self pollinated crop
2. Cross pollinated crop
3. Often cross pollinated crop
4. Hybrid crops

Correct Answer: 1

Explanation:

• In self-pollinated crops, prolonged rouging (removal of off-types) does not affect genetic purity because selfing maintains homozygosity.
• In cross-pollinated crops, rouging must be done carefully and timely, as contamination can occur from neighboring plants.

 

 

Question 117

Synthetic seeds have:

1. Zygotic embryo
2. Apomictic embryo
3. Somatic embryo
4. Fertilized embryo

Correct Answer: 3

Explanation:

• Synthetic seeds (artificial seeds)– Encapsulated somatic embryos (from tissue culture) inside a gel matrix (e.g., sodium alginate). They are used for propagation and germplasm conservation.
• Zygotic, apomictic, fertilized embryos– Not used for synthetic seeds.

 

 

Question 118

For accuracy of agricultural experiments, what level of probability is acceptable?

1. 1%
2. 5%
3. 10%
4. 15%

Correct Answer: 2

Explanation:

• In agricultural experiments, the standard acceptable level of probability (significance level, α) is 5% (0.05).
• This means there is a 5% chance of a Type I error (rejecting a true null hypothesis).
• 1%– More stringent; used in some fields.
• 10%, 15%– Less stringent; not commonly accepted.

 

 

Question 119

Albinism in plants is associated with:

1. Epistasis
2. Recessive lethal
3. Dominant lethal
4. Chromosome duplication

Correct Answer: 2

Explanation:

• Albinism(lack of chlorophyll) in plants is often caused by recessive lethal alleles (homozygous recessive condition leads to death due to inability to photosynthesize).
• Epistasis– Gene interaction, not directly lethal.
• Dominant lethal– Kills even in heterozygous condition (rare in plants).
• Chromosome duplication– Not associated with albinism.

 

 

Question 120

Recurrent selection is mostly used in:

1. Self pollinated crops
2. Cross pollinated crops
3. Vegetatively propagated crops
4. Apomictic crop plants

Correct Answer: 2

Explanation:

• Recurrent selection– A breeding method used primarily in cross-pollinated crops to improve the frequency of favorable alleles in a population by selecting and intermating selected individuals over multiple cycles.
• Self pollinated crops– Use pedigree, bulk, or SSD methods.
• Vegetatively propagated crops– Use clonal selection.
• Apomictic crops– Propagate through seeds without fertilization.