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

 

Question 80

The international organisation set up with the aim of reducing restrictions in trade between countries is:

1. GATT
2. WTO
3. FAO
4. UNO

Correct Answer: 2

Explanation:

• WTO (World Trade Organization)– Established in 1995 to regulate international trade and reduce trade barriers between countries.
• GATT (General Agreement on Tariffs and Trade)– Predecessor to WTO (1947), but the question asks for the organization set up with that aim (WTO).
• FAO (Food and Agriculture Organization)– Focuses on food security and agriculture.
• UNO (United Nations Organization)– Broad international body.
• Therefore, the correct answer is WTO→ Option 2.

 

 

Question 81

The tomato species which shows resistance to fusarium wilt, early blight, leaf curl, low temperature tolerance and high ascorbic acid is:

1. Solanum lycopersicum
2. Solanum peruvianum
3. Solanum pimpinellifolium
4. Solanum galapageense

Correct Answer: 3

Explanation:

• Solanum pimpinellifolium(currant tomato) – A wild relative of cultivated tomato. It exhibits resistance to fusarium wilt, early blight, leaf curl, low temperature tolerance, and high ascorbic acid content.
• lycopersicum– Cultivated tomato (susceptible to many diseases).
• peruvianum– Wild species, resistant to some diseases but not all listed.
• galapageense– Wild species from Galapagos.
• Therefore, the correct answer is Solanum pimpinellifolium→ Option 3.

 

 

Question 82

A set of germplasm accessions derived from base collection to represent the genetic spectrum in the whole collection is called:

1. Active collection
2. Working collection
3. Indigenous collection
4. Core collection

Correct Answer: 4

Explanation:

• Core collection– A subset of the entire germplasm collection (base collection) that captures the maximum genetic diversity (usually about 10% of the total accessions) with minimum redundancy.
• Active collection– Medium-term storage for distribution and research.
• Working collection– Actively used in breeding programs.
• Indigenous collection– Local or native germplasm.
• Therefore, the correct answer is Core collection→ Option 4.

 

 

Question 83

The linkage arrangement in a dihybrid in which the two dominant genes are on one chromosome and their corresponding recessive alleles are on the homologous chromosome. This type of arrangement of genes indicates:

1. Repulsion phase
2. Chiasma
3. Coupling phase
4. Crossing over

Correct Answer: 3

Explanation:

• Coupling phase (cis arrangement)– The two dominant alleles are on one chromosome and the two recessive alleles are on the homologous chromosome (e.g., AB/ab).
• Repulsion phase (trans arrangement)– One dominant and one recessive on each chromosome (e.g., Ab/aB).
• Chiasma– The site of crossing over.
• Crossing over– Exchange of genetic material.
• Therefore, the correct answer is Coupling phase→ Option 3.

 

 

Question 84

Incorporation of two or more major genes in the host for specific resistance to pathogen is called:

1. Gene deployment
2. Gene pyramiding
3. Multi lines
4. Vertical resistance

Correct Answer: 2

Explanation:

• Gene pyramiding– The process of incorporating two or more major (R) genes into a single crop variety to provide more durable and broad-spectrum resistance.
• Gene deployment– The strategic placement of different resistance genes in space and time.
• Multi lines– A mixture of lines with different resistance genes.
• Vertical resistance– Race-specific resistance (often controlled by one or few genes).
• Therefore, the correct answer is Gene pyramiding→ Option 2.

 

 

Question 85

Imperial Council of Agricultural Research was renamed as Indian Council of Agricultural Research on:

1. January 1950
2. August 1947
3. March 1946
4. March 1951

Correct Answer: 3

Explanation:

• The Imperial Council of Agricultural Researchwas established in 1929.
• It was renamed as the Indian Council of Agricultural Research (ICAR)in March 1946 (before Indian independence).
• Therefore, the correct answer is March 1946→ Option 3.

 

 

Question 86

Traditional knowledge is a form of Intellectual Property Right which is categorised under:

1. Primary Rights
2. Copyrights
3. Sui-generis Rights
4. Patent Rights

Correct Answer: 3

Explanation:

• Sui-generis rights– A special category of intellectual property rights designed for traditional knowledge (TK) and plant variety protection, as they do not fit into conventional IPR categories (patents, copyrights, trademarks).
• Copyrights– For literary and artistic works.
• Patent rights– For inventions.
• Primary Rights– Not a standard IPR category.
• Therefore, the correct answer is Sui-generis Rights→ Option 3.

 

 

Question 87

Under Plant Variety Rights Act, an Extant Variety can be legally registered and protected for a period of:

1. Initially nine years and a maximum of 18 years
2. Initially nine years and a maximum of 15 years
3. Initially 12 years and a maximum of 20 years
4. Initially six years and a maximum of 15 years

Correct Answer: 1

Explanation:

• Under the PPV&FR Act, 2001(India):
  • Extant varieties(already notified and released) can be registered for a period of 9 years initially, renewable for a maximum of 18 years (total).
  • New varieties– 15 years (annuals) or 18 years (trees/vines).
• Therefore, the correct answer is Initially nine years and a maximum of 18 years→ Option 1.

 

 

Question 88

Bajra Napier hybrids are an example of:

1. Intraspecific Hybrid
2. Tetraploids
3. Fixing Heterosis
4. Chromosome transfer

Correct Answer: 1

Explanation:

• Bajra Napier hybrids– Hybrids between pearl millet (Pennisetum glaucum) and Napier grass (Pennisetum purpureum). These are interspecific hybrids (between two species), but the option says intraspecific (within species). The answer key indicates Intraspecific Hybrid – this may be an error in the key. Typically, bajra-napier is interspecific.
• Given the key, the correct answer is Intraspecific Hybrid→ Option 1.

 

 

Question 89

In a living organism, a mechanism that can cause a gene to move from one linkage group to another is called:

1. Inversion
2. Duplication
3. Crossing over
4. Translocation

Correct Answer: 4

Explanation:

• Translocation– A chromosomal rearrangement where a segment of one chromosome is transferred to a non-homologous chromosome. This can cause a gene to move from one linkage group (chromosome) to another.
• Inversion– A segment reversed within the same chromosome (no movement to another linkage group).
• Duplication– A segment repeated within the same chromosome.
• Crossing over– Exchange between homologous chromosomes (same linkage group).
• Therefore, the correct answer is Translocation→ Option 4.

 

Question 90

The site of dark reactions of photosynthesis is:

1. Grana
2. Stroma
3. Thylakoids
4. Membrane system

Correct Answer: 2

Explanation:

• Dark reactions (Calvin cycle)– The light-independent reactions of photosynthesis occur in the stroma of chloroplasts.
• Grana– Stacks of thylakoids (site of light reactions).
• Thylakoids– Site of light reactions (photosystems, electron transport).
• Membrane system– Refers to thylakoid membranes.
• Therefore, the correct answer is Stroma→ Option 2.

 

Question 91

Which of the following species of potato is a pentaploid?

1. Solanum tuberosum
2. Solanum chaucha
3. Solanum curtilobum
4. Solanum stenotomum

Correct Answer: 2

Explanation:

• Solanum chaucha– A cultivated potato species from the Andes, known to be pentaploid (2n = 5x = 60) .
• Solanum tuberosum– The common potato, tetraploid (2n = 4x = 48).
• Solanum curtilobum– Triploid (2n = 3x = 36).
• Solanum stenotomum– Diploid (2n = 2x = 24).
• Therefore, the correct answer is Solanum chaucha→ Option 2.

 

Question 92

Which form of rice possesses more dextrin in its endosperm?

1. Wild rice
2. Parboiled rice
3. Glutinous rice
4. Hand pound

Correct Answer: 3

Explanation:

• Glutinous rice(also called sticky rice or waxy rice) – Contains high amounts of dextrin (and amylopectin), giving it a sticky texture when cooked.
• Wild rice– Not a true rice, different composition.
• Parboiled rice– Processed to retain nutrients, but not high in dextrin.
• Hand pound rice– Traditional milling, not high in dextrin.
• Therefore, the correct answer is Glutinous rice→ Option 3.

 

Question 93

The first man-made crop ‘Triticale’ is derived by crossing:

1. Triticum × Secale
2. Monococcum × Wild Einkorn
3. Triticum × Emmer
4. AA × BB genome

Correct Answer: 1

Explanation:

• Triticale– The first man-made cereal crop, derived by crossing wheat (Triticum) with rye (Secale) .
• The cross combines the yield and quality of wheat with the hardiness and disease resistance of rye.
• Monococcum × Wild Einkorn– Involves wheat species but not rye.
• Triticum × Emmer– Wheat × wheat cross.
• AA × BB genome– Refers to Brassica
• Therefore, the correct answer is Triticum × Secale→ Option 1.

 

Question 94

A cell or organism having a genomic formula 2n-1 is:

1. Monoploid
2. Nullisomic
3. Monosomic
4. Trisomic

Correct Answer: 3

Explanation:

• Monosomic (2n-1)– Aneuploid condition where one chromosome is missing from the diploid set (one copy instead of two).
• Monoploid (n)– A single set of chromosomes (haploid).
• Nullisomic (2n-2)– Missing a pair of chromosomes.
• Trisomic (2n+1)– An extra chromosome.
• Therefore, the correct answer is Monosomic→ Option 3.

 

Question 95

A bell shaped distribution of continuous phenotypic variation is called:

1. Continuous distribution
2. Polygenic distribution
3. Poisson distribution
4. Gaussian distribution

Correct Answer: 4

Explanation:

• Gaussian distribution(Normal distribution) – A bell-shaped, symmetrical distribution of continuous phenotypic variation, characteristic of polygenic traits influenced by many genes and environment.
• Continuous distribution– General term for traits showing a range of phenotypes.
• Polygenic distribution– Not a standard statistical term.
• Poisson distribution– A discrete distribution for rare events.
• Therefore, the correct answer is Gaussian distribution→ Option 4.

 

 

Question 96

How many days after fertilization does the lint in cotton come to maturity?

1. 45-50 days
2. 20-25 days
3. 100-105 days
4. 75-80 days

Correct Answer: 1

Explanation:

• Lint development in cotton– After fertilization, the lint (cotton fibre) matures in approximately 45-50 days.
• The fibre elongation phase occurs rapidly, followed by secondary cell wall thickening.
• Therefore, the correct answer is 45-50 days→ Option 1.

 

 

Question 97

A statistical measurement of how closely two sets of sample data are associated having limits ± 1 is:

1. Combining ability
2. Regression coefficient
3. Correlation coefficient
4. Cluster analysis

Correct Answer: 3

Explanation:

• Correlation coefficient (r)– A statistical measure that indicates the strength and direction of the linear relationship between two variables. Its value ranges from -1 to +1 (limits ±1).
• Combining ability– A genetic parameter.
• Regression coefficient– Indicates the slope of the regression line (not limited to ±1).
• Cluster analysis– Grouping method, not a measure of association.
• Therefore, the correct answer is Correlation coefficient→ Option 3.

 

Question 98

The method developed by Hayman to estimate the various components of genetic variance using six population is:

1. Quadrilateral analysis
2. Generation mean analysis
3. Line × Tester analysis
4. Triallel analysis

Correct Answer: 2

Explanation:

• Generation mean analysis– Developed by Hayman (1958) to estimate the various components of genetic variance (additive, dominance, and epistatic effects) using six populations (P₁, P₂, F₁, F₂, BC₁, BC₂).
• Quadrilateral analysis– Not a standard term.
• Line × Tester analysis– Used for combining ability analysis (Kempthorne).
• Triallel analysis– A mating design.
• Therefore, the correct answer is Generation mean analysis→ Option 2.

 

Question 99

Hybrid varieties were first commercially exploited in:

1. Bajra
2. Cotton
3. Tomato
4. Maize

Correct Answer: 4

Explanation:

• Maize (corn)– The first crop where hybrid varieties were commercially exploited on a large scale (starting in the 1920s-1930s in the USA).
• Bajra, cotton, tomato– Hybrid varieties were developed later.
• Therefore, the correct answer is Maize→ Option 4.

 

Question 100

The ability of an inbred to transmit desired performance to its hybrid progenies is:

1. Specific combining ability
2. General combining ability
3. Combining ability
4. Translation

Correct Answer: 2

Explanation:

• General combining ability (GCA)– The ability of an inbred line to transmit desired performance to its hybrid progenies in crosses with a range of other lines (due to additive gene effects).
• Specific combining ability (SCA)– Performance in a specific cross combination (due to non-additive effects).
• Combining ability– General term encompassing both GCA and SCA.
• Translation– Protein synthesis.
• Therefore, the correct answer is General combining ability→ Option 2.

 

Question 101

The form of nitrogen which is available in urea is:

1. Ammoniacal
2. Amide
3. Nitrite
4. Nitrate

Correct Answer: 2

Explanation:

• Urea [CO(NH₂)₂]– Contains nitrogen in the amide form (NH₂ group).
• Urea is converted to ammoniacal form (NH₄⁺) in the soil by the enzyme urease before plants can absorb it.
• Therefore, the correct answer is Amide→ Option 2.

 

 

Question 102

It is the major constituent of cotton fibre:

1. Cellulose
2. Protein
3. Lignin
4. Fat

Correct Answer: 1

Explanation:

• Cotton fibreis composed of approximately 90-95% cellulose (a polysaccharide of glucose).
• Protein, lignin, fat– Present in very small amounts.
• Therefore, the correct answer is Cellulose→ Option 1.

 

 

Question 103

Name of the protein present in wheat is:

1. Zein
2. Gluten
3. Dhurin
4. Ricin

Correct Answer: 2

Explanation:

• Gluten– The major storage protein complex in wheat (composed of glutenin and gliadin). It is responsible for the elasticity and dough-forming properties of wheat flour.
• Zein– Protein in maize.
• Dhurin– Not a standard protein name (possibly a misspelling of dhurrin, a cyanogenic glycoside in sorghum).
• Ricin– Toxic protein in castor bean.
• Therefore, the correct answer is Gluten→ Option 2.

 

 

Question 104

Capitulum or Head is the characteristic of the family:

1. Compositae (Asteraceae)
2. Solanaceae
3. Umbelliferae (Apiaceae)
4. Gramineae (Poaceae)

Correct Answer: 1

Explanation:

• Capitulum (head)– A compact inflorescence characteristic of the family Compositae (Asteraceae) , consisting of many small flowers (florets) arranged on a receptacle.
• Solanaceae– Solitary or cymose inflorescence.
• Umbelliferae– Umbel inflorescence.
• Gramineae– Spikelet inflorescence.
• Therefore, the correct answer is Compositae→ Option 1.

 

 

Question 105

Varalaxmi is a hybrid of:

1. Rice
2. Sorghum
3. Maize
4. Cotton

Correct Answer: 4

Explanation:

• Varalaxmi– A well-known cotton hybrid developed in India (intra-hirsutum hybrid).
• Therefore, the correct answer is Cotton→ Option 4.

 

 

Question 106

It is an example for often cross pollinated crop:

1. Green gram
2. Paddy
3. Cucumber
4. Red gram

Correct Answer: 4

Explanation:

• Often cross pollinated crops– Crops that are primarily self-pollinated but have a significant level of cross-pollination (5-30%).
• Red gram (pigeon pea, Cajanus cajan)– An often cross-pollinated crop (cross-pollination up to 30%).
• Green gram, paddy– Self-pollinated.
• Cucumber– Cross-pollinated.
• Therefore, the correct answer is Red gram→ Option 4.

 

 

Question 107

Seed plot technique is used in the seed production of:

1. Castor
2. Potato
3. Cotton
4. Gram

Correct Answer: 2

Explanation:

• Seed plot technique– A specialized method for producing virus-free potato seed tubers by growing potatoes in high-altitude, cool, aphid-free areas.
• Castor, cotton, gram– Do not use this technique.
• Therefore, the correct answer is Potato→ Option 2.

 

 

Question 108

Which one is an example for C₄ plant?

1. Cotton
2. Sugarcane
3. Soybean
4. Potato

Correct Answer: 2

Explanation:

• C₄ plants– Plants that fix CO₂ into a 4-carbon compound (oxaloacetate) in mesophyll cells before transferring it to bundle sheath cells for the Calvin cycle. They have Kranz anatomy.
• Sugarcane– A classic example of a C₄ plant.
• Cotton, soybean, potato– C₃ plants.
• Therefore, the correct answer is Sugarcane→ Option 2.

 

 

Question 109

National organization involved in seed production is:

1. NSC
2. ISST
3. CRIDA
4. NSRTC

Correct Answer: 1

Explanation:

• NSC (National Seeds Corporation)– A Government of India undertaking involved in the production and distribution of quality seeds.
• ISST– Indian Society of Seed Technology.
• CRIDA– Central Research Institute for Dryland Agriculture.
• NSRTC– Not a standard seed production organization.
• Therefore, the correct answer is NSC→ Option 1.

 

Question 110

GA₃ spray is recommended in hybrid rice to enhance:

1. Pollen viability
2. Seed viability
3. Tillering
4. Panicle exertion

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).
• Pollen viability, seed viability, tillering– Not the primary purpose.
• Therefore, the correct answer is Panicle exertion→ Option 4.

 

 

Question 111

Which one is a vitamin A precursor?

1. Thiamine
2. Pyridoxine
3. Beta-carotene
4. Cobalamine

Correct Answer: 3

Explanation:

• Beta-carotene– A carotenoid pigment that is a precursor of vitamin A (retinol). The human body converts beta-carotene into vitamin A.
• Thiamine– Vitamin B₁.
• Pyridoxine– Vitamin B₆.
• Cobalamine– Vitamin B₁₂.
• Therefore, the correct answer is Beta-carotene→ Option 3.

 

 

Question 112

The structure of chromosome can be seen at:

1. Anaphase
2. Metaphase
3. Prophase
4. Telophase

Correct Answer: 2

Explanation:

• Metaphase– Chromosomes are most highly condensed and aligned at the equatorial plate, making them most visible and distinct under a light microscope for karyotype analysis.
• Prophase– Chromosomes are condensing but not fully condensed.
• Anaphase– Sister chromatids are separating.
• Telophase– Chromosomes decondensing.
• Therefore, the correct answer is Metaphase→ Option 2.

 

 

Question 113

Blue green algae are:

1. Actinomycetes
2. Prokaryotes
3. Acellular
4. Eukaryotes

Correct Answer: 2

Explanation:

• Blue green algae (cyanobacteria)– Prokaryotic organisms (lack a true nucleus and membrane-bound organelles). They perform oxygenic photosynthesis.
• Actinomycetes– Filamentous bacteria.
• Acellular– Not cells (e.g., viruses).
• Eukaryotes– Have a true nucleus (e.g., green algae, plants).
• Therefore, the correct answer is Prokaryotes→ Option 2.

 

Question 114

Heterosis can be easily fixed in:

1. Self-pollinated crops
2. Apomictic crops
3. Cross pollinated crops
4. Cleistogamous crops

Correct Answer: 2

Explanation:

• Apomictic crops– Reproduce asexually through seeds (apomixis), which allows the fixation of heterosis because the hybrid genotype is preserved without segregation.
• Self-pollinated crops– Heterosis is lost in subsequent generations due to inbreeding depression.
• Cross pollinated crops– Need to produce fresh hybrid seeds each year.
• Cleistogamous crops– Closed flowers promote self-pollination (not fix heterosis).
• Therefore, the correct answer is Apomictic crops→ Option 2.

 

Question 115

Biological organism responsible for Nitrogen fixation is:

1. Bacillus
2. Agrobacterium
3. Striga
4. Rhizobium

Correct Answer: 4

Explanation:

• Rhizobium– A genus of bacteria that forms symbiotic nitrogen-fixing nodules on legume roots.
• Bacillus– Some species fix nitrogen (free-living), but not the primary symbiotic one.
• Agrobacterium– Causes crown gall; not a nitrogen fixer.
• Striga– A parasitic plant (witchweed), not a nitrogen fixer.
• Therefore, the correct answer is Rhizobium→ Option 4.

 

 

Question 116

Krebs cycle is also known as:

1. HMP shunt
2. TCA cycle
3. Calvin cycle
4. Glyoxylate cycle

Correct Answer: 2

Explanation:

• Krebs cycle– Also called the Tricarboxylic Acid (TCA) cycle or Citric Acid cycle. It is a series of reactions in mitochondria that oxidizes acetyl-CoA to produce energy (ATP, NADH, FADH₂).
• HMP shunt– Hexose monophosphate pathway (pentose phosphate pathway).
• Calvin cycle– Carbon fixation in photosynthesis.
• Glyoxylate cycle– A variation of the TCA cycle in germinating oilseeds.
• Therefore, the correct answer is TCA cycle→ Option 2.

 

 

Question 117

In biological nitrogen fixation, which one of the following elements has greater significance:

1. Nickel
2. Molybdenum
3. Sulphur
4. Potassium

Correct Answer: 2

Explanation:

• Molybdenum (Mo)– An essential component of the nitrogenase enzyme (the enzyme that fixes atmospheric N₂ to NH₃). It is also a component of nitrate reductase.
• Nickel– Component of urease, not nitrogenase.
• Sulphur– Component of some amino acids and proteins.
• Potassium– Osmotic regulation and enzyme activation.
• Therefore, the correct answer is Molybdenum→ Option 2.

 

 

Question 118

Maize protein is deficient in:

1. Betadine
2. Lysine
3. Tryptophane and lysine
4. Tryptophane

Correct Answer: 3

Explanation:

• Maize (corn)protein (zein) is deficient in the essential amino acids lysine and tryptophan.
• This deficiency can cause pellagra (niacin deficiency) when maize is the sole dietary staple.
• Quality Protein Maize (QPM)has been developed with higher levels of lysine and tryptophan (using the *opaque-2* gene).
• Therefore, the correct answer is Tryptophane and lysine→ Option 3.

 

 

Question 119

Black heart of potato is caused due to the deficiency of:

1. Oxygen
2. Iron
3. Zinc
4. Boron

Correct Answer: 1

Explanation:

• Black heart of potato– A physiological disorder caused by oxygen deficiency (anaerobic conditions) during storage. The center of the tuber turns black due to tissue death.
• Iron deficiency– Interveinal chlorosis.
• Zinc deficiency– Stunted growth, white bud in maize.
• Boron deficiency– Cracked stem, black tip of mango.
• Therefore, the correct answer is Oxygen→ Option 1.

 

 

Question 120

Which one is an essential part of photosynthesis?

1. Glycolysis
2. Plastolysis
3. Photorespiration
4. None of these

Correct Answer: 4

Explanation:

• Essential parts of photosynthesis– Light reactions (thylakoid) and dark reactions (Calvin cycle in stroma).
• Glycolysis– Breakdown of glucose (not part of photosynthesis).
• Plastolysis– Not a standard term related to photosynthesis.
• Photorespiration– A wasteful process (not essential; it occurs when Rubisco fixes O₂ instead of CO₂).
• Therefore, none of the options are essential parts of photosynthesis → Option 4.