Question 81

Genes that tend to be inherited together are said to be:

1. Associated
2. Related
3. Similar
4. Linked

Correct Answer: 4

Explanation:

• Linked genes– Genes located close together on the same chromosome that are inherited together because crossing over between them is rare.
• Linkage– Violates Mendel’s law of independent assortment.
• Complete linkage– No crossing over (genes always inherited together).
• Partial linkage– Some crossing over occurs (recombinants produced).

 

 

Question 82

Disruptive selection is a form of:

1. Pure line selection
2. Mass selection
3. Recurrent selection
4. Clonal selection

Correct Answer: 2

Explanation:

• Disruptive selection– A type of mass selection where selection favors both extremes of a trait distribution against the intermediate.
  • Example: Selecting very tall and very short plants, discarding medium height plants.
• Mass selection– Selecting and bulking seeds from many desirable plants based on phenotype.
• Recurrent selection– Used for population improvement in cross-pollinated crops.
• Pure line selection– For self-pollinated crops.

 

 

Question 83

Reciprocal recurrent selection is used when a character is governed by:

1. Additive genes
2. Non-additive genes
3. Both additive and non-additive genes
4. Cytoplasmic

Correct Answer: 3

Explanation:

• Reciprocal recurrent selection (RRS)– A breeding method that improves both general combining ability (GCA) (additive) and specific combining ability (SCA) (non-additive) simultaneously.
  • Two populations are developed and evaluated for cross performance.
  • Used in cross-pollinated crops (maize, sunflower) for hybrid development.
• Additive genes– Improve GCA.
• Non-additive genes– Improve SCA.

 

 

Question 84

The most effective method for the transfer of oligogenic character is:

1. Pedigree breeding
2. Bulk breeding
3. Backcross breeding
4. Disruptive breeding

Correct Answer: 3

Explanation:

• Backcross breeding– Most effective for transferring oligogenic (qualitative) characters (e.g., disease resistance) from a donor parent to an elite recurrent parent.
  • Only 5-6 backcrosses are needed to recover the recurrent parent genotype.
• Pedigree method– For selecting segregants from crosses between two adapted parents.
• Bulk method– For population improvement under natural selection.
• Disruptive breeding– Not standard.

 

 

Question 85

First intergeneric cross between bread wheat and Rye was made by:

1. Koeleureter (1760)
2. Andrew Knight (1835)
3. Rimpu (1890)
4. Muntzing (1951)

Correct Answer: 3

Explanation:

• Rimpu (1890)– First intergeneric cross between bread wheat (Triticum aestivum) and rye (Secale cereale) , leading to the development of Triticale.
• Koeleureter– Worked on interspecific crosses.
• Andrew Knight– Studied pea hybridization.
• Muntzing– Studied Triticale cytogenetics.

 

 

Question 86

Undesirable linkage can be broken more effectively by:

1. Pedigree method
2. Backcross method
3. Diallel selective mating
4. Bulk method

Correct Answer: 4

Explanation:

• Bulk method– In this method, segregating populations are grown in bulk without selection, allowing natural crossing over and recombination to break undesirable linkages over generations.
• Pedigree method– Selection is practiced early, which may retain linkages.
• Backcross method– Used for gene transfer, not specifically for breaking linkages.
• Diallel selective mating– For population improvement.

 

 

Question 87

Bulk breeding method was developed by:

1. Johannsen (1903)
2. Shull (1908)
3. Nilsson Ehle (1908)
4. Allard (1960)

Correct Answer: 3

Explanation:

• Nilsson Ehle (1908)– Swedish plant breeder who developed the bulk breeding method (also called mass method or population method).
  • Used for handling segregating populations in self-pollinated crops.
• Johannsen– Developed pure line theory.
• Shull– Developed hybrid maize breeding.
• Allard– Worked on plant breeding and population genetics.

 

 

Question 88

Hybrid progeny from a cross between two inbreds is known as:

1. Single cross hybrid
2. Double cross hybrid
3. Three way cross hybrid
4. Multiple cross hybrid

Correct Answer: 1

Explanation:

• Single cross hybrid– Progeny from a cross between two inbred lines (A × B).
• Double cross hybrid– (A × B) × (C × D).
• Three way cross hybrid– (A × B) × C.
• Multiple cross hybrid– More than two parents.

 

 

Question 89

Which of the following eukaryotic cell structures does not contain DNA?

1. Nucleus
2. Mitochondrion
3. Endoplasmic reticulum
4. Chloroplast

Correct Answer: 3

Explanation:

• Endoplasmic reticulum (ER)– A membrane-bound organelle involved in protein synthesis (rough ER) and lipid synthesis (smooth ER). Does not contain DNA.
• Nucleus– Contains nuclear DNA.
• Mitochondrion– Contains mtDNA (circular).
• Chloroplast– Contains cpDNA (circular).

 

 

Question 90

The physical appearance of an organism for a given trait is termed:

1. Genetics
2. Phenotype
3. Synapsis
4. Genotype

Correct Answer: 2

Explanation:

• Phenotype– The observable physical appearance or expression of a trait (e.g., tall, dwarf, yellow seed, purple flower).
  • Determined by genotype + environment.
• Genotype– The genetic constitution.
• Genetics– The study of heredity.
• Synapsis– Pairing of homologous chromosomes during meiosis.

 

 

Question 91

Rice production is highest in:

1. Haryana
2. Punjab
3. West Bengal
4. Uttar Pradesh

Correct Answer: 3

Explanation:

• West Bengal– The largest rice-producing state in India.
• Uttar Pradesh– Second largest.
• Punjab– High productivity but lower total area.
• Haryana– Significant but less.

 

 

Question 92

Under stress conditions, which amino acid accumulates in crop plants?

1. Methionine
2. Proline
3. Phenyl alanine
4. Isoleucine

Correct Answer: 2

Explanation:

• Proline– A compatible osmolyte that accumulates in plants under drought, salinity, cold, and heavy metal stress.
  • Functions: Osmotic adjustment, ROS scavenging, protection of cellular structures.
• Methionine, phenyl alanine, isoleucine– Not primarily stress-associated.

 

 

Question 93

Chromosomes are most condensed at:

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

Correct Answer: 2

Explanation:

• Metaphase– Chromosomes are most highly condensed and aligned at the equatorial plate. This is the best stage for karyotyping.
• Prophase– Chromosomes are condensing but not fully.
• Anaphase– Chromatids are separating.
• Telophase– Chromosomes are decondensing.

 

 

Question 94

President of ICAR is:

1. Prime Minister
2. Union Minister of Agriculture
3. Director General of ICAR
4. Secretary of Agriculture

Correct Answer: 2

Explanation:

• The President of ICARis the Union Minister of Agriculture (ex-officio).
• The Director Generalis the executive head (ex-officio Secretary to the Government of India).

 

 

Question 95

Press Mud is a by-product of which industry?

1. Tannery
2. Sugar Industry
3. Paper mill
4. Distillery

Correct Answer: 2

Explanation:

• Press mud (filter cake)– A by-product of the sugar industry (sugarcane processing). Used as an organic manure (rich in nitrogen, phosphorus, calcium, organic matter).
• Tannery– Produces tannery sludge.
• Paper mill– Produces pulp waste.
• Distillery– Produces spent wash.

 

 

Question 96

The purine and pyrimidine pairing in DNA is:

1. A—T, G—C
2. A—C, T—G
3. A—T, G—C 
4. A—G, T—C

Correct Answer: 1

Explanation:

• Chargaff’s rules:A = T, G = C.
• A pairs with T(2 H-bonds).
• G pairs with C(3 H-bonds).

 

 

Question 97

The process of conversion of organic form of nutrients into ammonia is:

1. Ammonification
2. Nitrification
3. Denitrification
4. None of these

Correct Answer: 1

Explanation:

• Ammonification– The decomposition of organic nitrogen (proteins, nucleic acids, urea) into ammonia (NH₃) by microorganisms (bacteria and fungi).
• Nitrification– NH₃ → NO₂⁻ → NO₃⁻.
• Denitrification– NO₃⁻ → N₂ (gas).

 

 

Question 98

UG 99 is related to:

1. Puccinia recondita
2. Puccinia graminis sp. tritici
3. Puccinia striiformis
4. Puccinia hordei

Correct Answer: 2

Explanation:

• UG99 (TTKSK)– A highly virulent race of stem rust (black rust) of wheat caused by Puccinia graminis sp. tritici.
  • First identified in Uganda in 1999(hence UG99).
  • Overcomes many resistance genes (e.g., Sr31).
• recondita– Leaf rust (brown rust).
• striiformis– Yellow rust (stripe rust).
• hordei– Barley rust.

 

 

Question 99

The statistical design most appropriate for laboratory experiments is:

1. LSD
2. CRD
3. CRBD
4. Factorial RBD

Correct Answer: 2

Explanation:

• CRD (Completely Randomized Design)– Most appropriate for laboratory experiments because:
  • Experimental units are homogeneous.
  • No blocking needed.
  • Simple and flexible.
• LSD (Least Significant Difference)– A post-hoc test.
• CRBD (Randomized Block Design)– For field experiments with heterogeneity.
• Factorial RBD– For studying interactions.

 

 

Question 100

The largest cell organelle is:

1. Chloroplast
2. Mitochondria
3. Peroxisome
4. Endoplasmic reticulum

Correct Answer: 1

Explanation:

• Chloroplast– The largest organelle in plant cells (up to 10 µm in length).
• Mitochondria– 0.5–1 µm.
• Peroxisome– 0.5–1 µm.
• Endoplasmic reticulum– Extensive membrane network but not a single large organelle.

 

 

Question 101

In which of the following crops, the Jerking Practice is adopted in hybrid seed production?

1. Sorghum
2. Tomato
3. Paddy
4. Bajra

Correct Answer: 1

Explanation:

• Jerking practice– A mechanical method of hybrid seed production in sorghum.
  • Involves pulling or jerking the inflorescence (panicle) of the male parent to release pollen, which is then dusted onto the female parent.
  • Used when natural cross-pollination is insufficient.
• Bajra (pearl millet)– Uses protogyny and wind pollination.
• Paddy (rice)– Uses CMS system and GA₃ spraying.
• Tomato– Hand emasculation and pollination.

 

 

Question 102

Which of the following is a soil fertility building crop?

1. Wheat
2. Mustard
3. Sunflower
4. Chickpea

Correct Answer: 4

Explanation:

• Chickpea (Cicer arietinum)– A leguminous pulse crop that forms symbiotic nitrogen-fixing nodules with Rhizobium.
  • Adds nitrogen to the soil (residual fertility).
  • Improves soil structure through root systems.
  • Used in crop rotation to build soil fertility.
• Wheat, mustard, sunflower– Non-leguminous crops that deplete soil nitrogen (not building).

 

 

Question 103

The scientist who coined the term ‘Cistron’ is:

1. Khorana
2. Straussberger
3. Johannsen
4. Benzer

Correct Answer: 4

Explanation:

• Seymour Benzer(1955-1960s) – Coined the terms Cistron, Recon, and Muton based on fine structure analysis of the rII locus of bacteriophage T4.
  • Cistron– The functional unit of DNA (equivalent to a gene).
  • Recon– The smallest unit of recombination (single nucleotide).
  • Muton– The smallest unit of mutation (single nucleotide).
• Khorana– Worked on genetic code.
• Johannsen– Coined “gene”.

 

 

Question 104

Lysosome is bound by:

1. Single unit membrane
2. Double unit membrane
3. No membrane
4. Triple unit membrane

Correct Answer: 1

Explanation:

• Lysosome– A single membrane-bound organelle (unit membrane) containing hydrolytic enzymes.
  • Functions: Digestion of intracellular and extracellular materials (autophagy, phagocytosis).
• Double membrane organelles:Mitochondria, chloroplasts, nucleus.
• Non-membranous:Ribosomes, centrioles.

 

 

Question 105

The physical basis of life is:

1. Protoplasm
2. Nucleus
3. Golgi apparatus
4. Mitochondria

Correct Answer: 1

Explanation:

• Protoplasm– The living substance of the cell (cytoplasm + nucleoplasm). It is considered the physical basis of life because all life processes occur within it.
• Nucleus– Contains genetic material.
• Golgi apparatus, mitochondria– Organelles involved in specific functions.

 

 

Question 106

The energy currency of the plant is:

1. K
2. N
3. P
4. S

Correct Answer: 3

Explanation:

• Phosphorus (P)– A component of ATP (adenosine triphosphate) , the energy currency of the cell. ATP stores and transfers energy for all cellular processes.
• K– Osmotic regulation, enzyme activation.
• N– Component of proteins, nucleic acids.
• S– Component of some amino acids.

 

 

Question 107

Which fertilizer is most beneficial for alkali soils?

1. Urea
2. Ammonium sulphate
3. CAN
4. Ammonium nitrate

Correct Answer: 2

Explanation:

• Ammonium sulphate ((NH₄)₂SO₄)– Most beneficial for alkali (sodic) soils because: Acidifying effect (lowers soil pH) due to nitrification releasing H⁺. Improves availability of nutrients.
• Urea, CAN, ammonium nitrate– Less acidifying.

 

 

Question 108

The brain child behind the Shantiniketan experiment is:

1. Albert M.
2. L. Brayne
3. Rabindranath Tagore
4. T. Mosher

Correct Answer: 3

Explanation:

• Shantiniketan experiment– A rural reconstruction and extension education experiment initiated by Rabindranath Tagore at Shantiniketan, West Bengal. Focused on rural development, education, and community participation.

 

 

Question 109

The microorganism producing fried egg colonies is:

1. Bacillus
2. Mycoplasma
3. Spirochete
4. Rickettsia

Correct Answer: 2

Explanation:

• Fried egg colonies– Characteristic of Mycoplasma colonies on solid media (small, round, with a dense center and translucent periphery).
• Bacillus– Produces large, irregular colonies.
• Spirochete, Rickettsia– Do not produce fried egg colonies.

 

 

Question 110

Plant part used in tissue culture is called:

1. Callus
2. Meristem
3. Explant
4. Protoplast

Correct Answer: 3

Explanation:

• Explant– The plant part (leaf, stem, root, meristem, embryo) taken from the parent plant and placed in culture for regeneration.
• Callus– Undifferentiated mass of cells derived from explants.
• Protoplast– Plant cell with cell wall removed.

 

 

Question 111

Intensification of crops, in both space and time dimension, refers to: (Repeat of 2016 Q7)

1. Sequential cropping
2. Double cropping
3. Mono cropping
4. Intercropping

Correct Answer: 4

Explanation:

• Intercropping– Growing two or more crops simultaneously on the same land (space and time intensification).
• Sequential cropping– Only time dimension.

 

 

Question 112

Chromosomal theory of inheritance was proposed by:

1. Mendel
2. Sutton-Boveri
3. Morgan
4. Darwin

Correct Answer: 2

Explanation:

• Sutton and Boveri(1902-1904) – Proposed the chromosomal theory of inheritance.
• Mendel– Laws of inheritance (without knowledge of chromosomes).
• Morgan– Linkage and crossing over.

 

 

Question 113

The mean value of parent A is 10, parent B is 6 and midparent value is 8. The mean value of F₁ hybrid is less than 10 and more than 8. Then it is:

1. Heterobeltiosis
2. No dominance
3. Partial dominance
4. Complete dominance

Correct Answer: 3

Explanation:

• Partial (incomplete) dominance– F₁ mean is between the two parents but closer to one parent (not exactly intermediate). Here: F₁ is between 8 and 10 (midparent is 8, parent A is 10).
• Heterobeltiosis– F₁ exceeds the better parent (not the case here).
• Complete dominance– F₁ equals the dominant parent.
• No dominance– F₁ equals midparent (8).

 

 

Question 114

During which stage of meiosis crossing over takes place?

1. Zygotene
2. Pachytene
3. Diplotene
4. Diakinesis

Correct Answer: 2

Explanation:

• Pachytene– The stage of prophase I where crossing over (exchange of genetic material between non-sister chromatids of homologous chromosomes) occurs.
• Zygotene– Pairing (synapsis) begins.
• Diplotene– Chiasmata visible.
• Diakinesis– Terminalization of chiasmata.

 

 

Question 115

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.
  • Primary method to maintain genetic purity in the field.
• Field inspection– To monitor but not directly control purity.
• Seed testing/labeling– After harvest.

 

 

Question 116

The phenotypic ratio in F₂ generation of dihybrid cross is:

1. 9:3:3:1
2. 3:9:3:1
3. 1:2:1
4. None of these

Correct Answer: 1

Explanation:

• Dihybrid cross– Two genes, independent assortment.
• F₂ phenotypic ratio– 9:3:3:1 (9 dominant for both, 3 dominant first/recessive second, 3 recessive first/dominant second, 1 recessive for both).

 

 

Question 117

Number of phenotypes in F₂ when five genes are segregating and in case of existence of complete dominance is equal to:

1. 32
2. 8
3. 16
4. 20

Correct Answer: 1

Explanation:

• Number of phenotypes in F₂ for n geneswith complete dominance = 2ⁿ. For n = 5, 2⁵ = 32.
• Number of genotypes= 3ⁿ (for n=5, 243).
• Number of gametesfrom F₁ = 2ⁿ.

 

 

Question 118

Which among the following pulse crops is regarded as ‘poor man’s pulse’?

1. Chickpea
2. Horse gram
3. Green gram
4. Black gram

Correct Answer: 2

Explanation:

• Horse gram (Macrotyloma uniflorum)– Called “poor man’s pulse” because:
  • Highly drought-tolerant, requires low inputs.
  • Affordable and nutritious.
  • Grown in rainfed and marginal lands.
• Chickpea– More expensive.

 

 

Question 119

The terms Vertical and Horizontal resistance were coined by:

1. Starkman, E.C.
2. Vanderplank, J.E.
3. Flor, H.H.
4. Fry, W.E.

Correct Answer: 2

Explanation:

• E. Vanderplank (1963)– Coined the terms vertical resistance (race-specific, oligogenic, monogenic) and horizontal resistance (race-nonspecific, polygenic).
• Flor, H.H.– Proposed the Gene-for-Gene hypothesis.

 

 

Question 120

The synthetic seed is:

1. Fluid drilled seed
2. Seed without seed coat
3. Seed tablet
4. Artificial seed

Correct Answer: 4

Explanation:

• Synthetic seed (artificial seed)– Encapsulated somatic embryos (from tissue culture) inside a gel matrix (e.g., sodium alginate).
  • Used for propagation and germplasm conservation.
• Fluid drilling– Sowing germinated seeds in gel.
• Seed tablet– Not a standard term.