ICAR JRF Plant Science Practice Series Memory Based 2024 (Module 1) (40 – 80 MCQ) 

 

Question 40

Barbara McClintock was awarded Nobel Prize in 1984 for the discovery of:

1. Split genes
2. Pseudo genes
3. Jumping genes
4. Overlapping genes

Correct Answer: 3

Explanation:

• Barbara McClintockdiscovered transposable elements (jumping genes) in maize (corn) in the 1940s-1950s.
• She was awarded the Nobel Prize in Physiology or Medicine in 1983(not 1984; the question has a typo).
• Split genes– Discovered by Richard Roberts and Phillip Sharp (Nobel 1993).
• Pseudo genes– Non-functional copies of genes.
• Overlapping genes– Genes that share nucleotide sequences.
• Therefore, the correct answer is Jumping genes→ Option 3.

 

 

Question 41

GEAC works under the Ministry of:

1. Science and Technology
2. Agriculture
3. Health
4. Environment and Forests

Correct Answer: 4

Explanation:

• GEAC (Genetic Engineering Appraisal Committee)– The regulatory body in India for the approval of genetically modified (GM) organisms and products.
• It works under the Ministry of Environment, Forest and Climate Change (MoEFCC).
• Therefore, the correct answer is Environment and Forests→ Option 4.

 

 

Question 42

During cell cycle, intensive cellular synthesis, division of mitochondria and chloroplasts, increase in energy stores and formation of mitotic spindle will occur in:

1. S phase
2. M Phase
3. G₁ Phase
4. G₂ Phase

Correct Answer: 4

Explanation:

• G₂ Phase (Gap 2 phase)– The period after DNA synthesis (S phase) and before mitosis (M phase). Key events include:
  • Intensive cellular synthesis (proteins, RNA)
  • Division of mitochondria and chloroplasts
  • Increase in energy stores
  • Formation of the mitotic spindle
• S phase– DNA replication.
• M phase– Mitosis and cytokinesis.
• G₁ phase– Cell growth, protein synthesis.
• Therefore, the correct answer is G₂ Phase→ Option 4.

 

 

Question 43

The first meiosis in the embryo sac mother cell of plants results in:

1. Four haploid embryo sac
2. One haploid embryo sac
3. Four haploid female gametophyte
4. Four ovule

Correct Answer: 3

Explanation:

• The embryo sac mother cell (megaspore mother cell)is diploid (2n).
• It undergoes meiosisto produce four haploid megaspores (female gametophytes).
• Only one of these four megaspores is functional and develops into the embryo sac.
• The question asks for the result of first meiosis– it produces four haploid female gametophytes (megaspores).
• Therefore, the correct answer is Four haploid female gametophyte→ Option 3.

 

 

Question 44

During transpiration pull, the force that is occurring between water molecules and the cell wall that is caused by hydrogen bonding is called:

1. Driving force
2. Cohesion
3. Adhesion
4. Tensile strength

Correct Answer: 3

Explanation:

• Adhesion– The attraction between water molecules and the cell wall (xylem vessels) due to hydrogen bonding. This helps water rise through the xylem.
• Cohesion– Attraction between water molecules themselves.
• Driving force– General term for transpiration pull.
• Tensile strength– Resistance to breaking under tension.
• Therefore, the correct answer is Adhesion→ Option 3.

 

Question 45

Which of the following chemical is used as anti-transpirant:

1. Succinic acid
2. Indole acetic acid
3. Phenyl mercuric acetate
4. Abscisic acid

Correct Answer: 3

Explanation:

• Phenyl mercuric acetate (PMA)– A chemical anti-transpirant that induces stomatal closure, reducing water loss.
• Succinic acid– Not an anti-transpirant.
• Indole acetic acid (IAA)– An auxin plant hormone.
• Abscisic acid (ABA)– A natural plant hormone that induces stomatal closure, but it is not a chemical anti-transpirant used commercially.
• Therefore, the correct answer is Phenyl mercuric acetate→ Option 3.

 

 

Question 46

The first miracle rice, IR 8 was produced in 1966 at IRRI, Philippines through a cross between:

1. Dee Geo Woo Gen × Peta
2. Indica × Japonica
3. Peta × Zizania palustris
4. TN1 × IR 6

Correct Answer: 1

Explanation:

• IR 8– The first high-yielding semi-dwarf rice variety (often called “miracle rice”) developed at IRRI in 1966.
• It was derived from a cross between Dee Geo Woo Gen(dwarf donor from Taiwan) and Peta (tall variety from Indonesia).
• Indica × Japonica– Crosses that produced other varieties.
• Therefore, the correct answer is Dee Geo Woo Gen × Peta→ Option 1.

 

 

Question 47

The type of nursery technique in rice suited for use with mechanical transplanter is:

1. Wet nursery
2. Dry nursery
3. Mat nursery
4. Dapog nursery

Correct Answer: 3

Explanation:

• Mat nursery– A method where rice seedlings are grown in a thin layer of soil/mat, which can be rolled and used with mechanical transplanters.
• Wet nursery– Traditional method with puddled soil.
• Dry nursery– Seedbed prepared under dry conditions.
• Dapog nursery– Seedlings grown on polythene sheets without soil; used for young seedlings.
• Therefore, the correct answer is Mat nursery→ Option 3.

 

 

Question 48

The minimum isolation distance needed for the foundation seed production of maize is:

1. 1000 m
2. 400 m
3. 1600 m
4. 100 m

Correct Answer: 2

Explanation:

• As per Indian Minimum Seed Certification Standards:
  • Foundation seed of maize (cross-pollinated)– Minimum isolation distance is 400 m.
  • Certified seed of maize– 200-400 m.
  • Foundation seed of self-pollinated crops– 3-10 m.
• Therefore, the correct answer is 400 m→ Option 2.

 

Question 49

Crop varieties are classified as homozygous variety and heterozygous variety. One of the following is a heterozygous variety:

1. Clonal variety
2. Composite variety
3. Pure line variety
4. Multiline variety

Correct Answer: 4

Explanation:

• Multiline variety– A mixture of several lines (often near-isogenic lines) that are each homozygous but differ from each other, making the variety heterogeneous. However, the question says “heterozygous variety” – multilines are heterogeneous, not necessarily heterozygous. The answer key indicates Multiline variety.
• Clonal variety– Genetically uniform (homozygous or heterozygous but propagated vegetatively).
• Composite variety– Mixture of genotypes, heterogeneous.
• Pure line variety– Homozygous and homogeneous.
• Therefore, the correct answer is Multiline variety→ Option 4.

 

Question 50

The hypothesis which explains heterosis as a result of complementation between divergent alleles is:

1. Over dominance hypothesis
2. Dominance hypothesis
3. Epistatic effects
4. Out breeding depression

Correct Answer: 1

Explanation:

• Over dominance hypothesis– Explains heterosis as the result of complementation between divergent alleles at a single locus, where the heterozygote (Aa) is superior to both homozygotes (AA and aa).
• Dominance hypothesis– Explains heterosis as the masking of harmful recessive alleles by dominant alleles.
• Epistatic effects– Non-allelic interactions.
• Out breeding depression– Opposite of heterosis.
• Therefore, the correct answer is Over dominance hypothesis→ Option 1.

 

Question 51

The most important insect species that damage the wheat grain during storage is:

1. Urochysis agropyri
2. Mythenna separate
3. Petrobia lateens
4. Trogoderma granarium

Correct Answer: 4

Explanation:

• Trogoderma granarium– The khapra beetle, a serious storage pest of wheat and other grains. It is highly destructive and difficult to control.
• Urochysis agropyri– Not a storage pest (related to wheat rust?).
• Mythenna separate– Armyworm (field pest, not storage).
• Petrobia lateens– Brown wheat mite (field pest).
• Therefore, the correct answer is Trogoderma granarium→ Option 4.

 

Question 52

Little leaf of brinjal is caused by:

1. Mycoplasma
2. Prions
3. Viroids
4. Fungi

Correct Answer: 1

Explanation:

• Little leaf of brinjal (eggplant)– A disease caused by phytoplasma (formerly called mycoplasma-like organisms).
• Symptoms: Small, narrow, chlorotic leaves, stunted growth, excessive branching (witches’ broom).
• Prions– Infectious proteins (cause mad cow disease).
• Viroids– Small, circular RNA molecules (e.g., potato spindle tuber viroid).
• Fungi– Not the cause of little leaf.
• Therefore, the correct answer is Mycoplasma→ Option 1.

 

Question 53

In plants, the Golgi complex is a dynamic structure consisting of one or more stacks. Each individual stack is called:

1. Dictyosome
2. Golgismone
3. Golgi network
4. Cisternae

Correct Answer: 1

Explanation:

• Dictyosome– Each individual stack of the Golgi complex in plant cells. In animal cells, the entire Golgi apparatus is called the Golgi complex, but in plants, each unit is a dictyosome.
• Golgismone– Not a standard term.
• Golgi network– The entire Golgi apparatus or the trans-Golgi network.
• Cisternae– The flattened membrane sacs that make up a dictyosome.
• Therefore, the correct answer is Dictyosome→ Option 1.

 

Question 54

The largest area in India is occupied by the soil group:

1. Black soil
2. Red soil
3. Alluvial soil
4. Lateritic soil

Correct Answer: 3

Explanation:

• Alluvial soil– Covers the largest area in India (about 43% of the total land area). Found in the Indo-Gangetic plains and river deltas.
• Black soil– Found in Deccan Plateau (cotton-growing region).
• Red soil– Found in Tamil Nadu, Karnataka, Andhra Pradesh.
• Lateritic soil– Found in high-rainfall areas (Western Ghats, Northeast).
• Therefore, the correct answer is Alluvial soil→ Option 3.

 

Question 55

A form of apomixis in which the embryo sac develops from a vegetative cell of the ovule:

1. Apogamy
2. Apospory
3. Diplospory
4. Asexual reproduction

Correct Answer: 2

Explanation:

• Apospory– A type of apomixis where the embryo sac develops directly from a vegetative cell (nucellus or integument) without meiosis. The resulting embryo sac is diploid.
• Apogamy– Development of the embryo from a cell of the embryo sac other than the egg (without fertilization).
• Diplospory– Development of the embryo sac from the megaspore mother cell without meiosis.
• Asexual reproduction– General term, not specific.
• Therefore, the correct answer is Apospory→ Option 2.

 

Question 56

The minimum progeny population size allowing for random union of all gametes arising from AaBbCc parent is:

1. 27
2. 9
3. 64
4. 36

Correct Answer: 1

Explanation:

• An individual with genotype AaBbCcproduces 2³ = 8 types of gametes.
• For random union of all possible gamete combinations (in a random mating population), the minimum population size needed to include all possible genotypes is 3ⁿ(where n = number of heterozygous genes). This gives 3³ = 27.
• Alternatively, the number of possible F₂ genotypes from a trihybrid cross is 27.
• Therefore, the correct answer is 27→ Option 1.

 

Question 57

During substitution mutation, transition is caused by the factor:

1. Tautomerization
2. Alkylating agents
3. Chemical mutagens
4. Physical mutagens

Correct Answer: 1

Explanation:

• Transition mutation– A point mutation where a purine is replaced by another purine (A ↔ G) or a pyrimidine by another pyrimidine (C ↔ T).
• Tautomerization– The temporary change in base structure (e.g., keto-enol tautomerism) can cause mispairing during DNA replication, leading to transition mutations.
• Alkylating agents, chemical mutagens, physical mutagens– Can cause both transitions and transversions, but tautomerization is specifically associated with transitions.
• Therefore, the correct answer is Tautomerization→ Option 1.

 

Question 58

While calculating different measures of variation, the square root of variance is termed as:

1. Coefficient of variation
2. Standard Deviation
3. Transgressive variation
4. Standard error

Correct Answer: 2

Explanation:

• Standard deviation (σ)– The square root of variance (σ²). It measures the spread of data around the mean.
• Coefficient of variation (CV)– (Standard deviation / mean) × 100.
• Transgressive variation– When offspring exceed both parents in a trait.
• Standard error (SE)– Standard deviation of the sampling distribution (σ/√n).
• Therefore, the correct answer is Standard Deviation→ Option 2.

 

Question 59

During the process of transcription, a mRNA molecule is:

1. transcribed from protein
2. translated from DNA
3. transcribed into DNA
4. translated into protein

Correct Answer: 2

Explanation:

• Transcription– The process of synthesizing mRNA from a DNA template (DNA → mRNA).
• Translation– The process of synthesizing protein from mRNA.
• Option 2– “translated from DNA” is incorrect terminology; it should be “transcribed from DNA”. However, among the options, it is the closest correct meaning. The answer key supports Option 2.
• Therefore, the correct answer is translated from DNA→ Option 2.

 

Question 60

Bulk breeding accomplishes inbreeding in segregating generations. If there are five segregating genes in a population, near homozygosity to 100 per cent will be achieved by:

1. F₂ generation
2. F₄ generation
3. F₆ generation
4. F₈ generation

Correct Answer: 4

Explanation:

• Bulk breeding– A method where segregating generations are advanced without selection, allowing natural selection and inbreeding.
• With 5 segregating genes, homozygosity increases with each generation of selfing. Near 100% homozygosity is typically achieved around F₈ generation(after 8 generations of selfing).
• F₂– 50% homozygosity.
• F₄– About 75% homozygosity.
• F₆– About 87.5% homozygosity.
• F₈– About 93.75% homozygosity (near 100%).
• Therefore, the correct answer is F₈ generation→ Option 4.

 

Question 61

The non-allelic interaction between or among genes controlling a trait is called:

1. Gene dose
2. G × E interaction
3. Epistasis
4. Pleiotropic effect

Correct Answer: 3

Explanation:

• Epistasis– The interaction between non-allelic genes (different genes/loci) where one gene masks or modifies the expression of another gene.
• Gene dose– Number of copies of a gene.
• G × E interaction– Interaction between genotype and environment.
• Pleiotropic effect– A single gene affects multiple traits.
• Therefore, the correct answer is Epistasis→ Option 3.

 

Question 62

The hybrid progeny between a single cross and an inbred line is referred to as:

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

Correct Answer: 1

Explanation:

• Three way cross hybrid– Produced by crossing a single cross hybrid (A × B) with an inbred line (C) → (A × B) × C.
• Double cross hybrid– (A × B) × (C × D).
• Double top cross– Single cross × open pollinated variety.
• Multiple cross– Involving more than two parents.
• Therefore, the correct answer is Three way cross hybrid→ Option 1.

 

Question 63

If the leaf tips look burnt, followed by older leaves turning a dark green or reddish-purple, then the deficiency symptom is due to the absence of:

1. Phosphorus
2. Calcium
3. Magnesium
4. Nitrogen

Correct Answer: 1

Explanation:

• Phosphorus deficiency– Symptoms include: older leaves turn dark green or reddish-purple (due to anthocyanin accumulation), leaf tips may become burnt or necrotic, stunted growth, delayed maturity.
• Calcium deficiency– Death of growing points, leaf tip burn, distorted leaves.
• Magnesium deficiency– Interveinal chlorosis in older leaves.
• Nitrogen deficiency– Uniform pale green to yellow leaves, stunted growth.
• Therefore, the correct answer is Phosphorus→ Option 1.

 

Question 64

The potential ability of a plant cell to express all its genetic information under appropriate conditions and to proceed through all the stages of development to produce a fully differentiated adult plant is called:

1. Regeneration
2. Vegetative propagation
3. Totipotency
4. Clonal propagation

Correct Answer: 3

Explanation:

• Totipotency– The ability of a single plant cell (or somatic cell) to express all its genetic information and differentiate into a complete, fully functional adult plant under appropriate conditions.
• Regeneration– The process of growing a whole plant from a tissue or cell.
• Vegetative propagation– Asexual reproduction using plant parts.
• Clonal propagation– Producing genetically identical copies.
• Therefore, the correct answer is Totipotency→ Option 3.

 

Question 65

The most dreaded disease of sugarcane that affects the crop to complete drying is caused by:

1. Cephalosporium sacchari
2. Scirpophaga excentalis
3. Colletotrichum falcatum
4. Ceratocystis paradoxa

Correct Answer: 3

Explanation:

• Colletotrichum falcatum– Causes red rot of sugarcane, one of the most destructive diseases, leading to complete drying and death of the crop.
• Cephalosporium sacchari– Causes wilt, but less severe.
• Scirpophaga excentalis– An insect pest (stalk borer), not a pathogen.
• Ceratocystis paradoxa– Causes pineapple disease, but not as devastating as red rot.
• Therefore, the correct answer is Colletotrichum falcatum→ Option 3.

 

Question 66

The enzyme amylase is produced commercially from the source:

1. Rhizopus
2. Aspergillus niger
3. Saccharomyces cerevisiae
4. Trichoderma viride

Correct Answer: 2

Explanation:

• Aspergillus niger– A fungus used commercially for the production of amylase (and also citric acid, pectinase, etc.).
• Rhizopus – Used for amylase and other enzymes, but A. nigeris more common.
• Saccharomyces cerevisiae– Used for alcoholic fermentation (yeast).
• Trichoderma viride– Used for cellulase production.
• Therefore, the correct answer is Aspergillus niger→ Option 2.

 

Question 67

More durable insect resistance in plants is found when the resistance is governed by:

1. Monogenic traits
2. Polygenic traits
3. Cytoplasmic inheritance
4. Environmental factors

Correct Answer: 2

Explanation:

• Polygenic traits(quantitative) – Controlled by many genes, each with small effect. Resistance is often more durable because the pathogen would need to overcome multiple genes simultaneously (difficult).
• Monogenic traits– Controlled by a single gene. Resistance can be easily broken by a single mutation in the pathogen.
• Cytoplasmic inheritance– Maternal inheritance, less common.
• Environmental factors– Not genetic resistance.
• Therefore, the correct answer is Polygenic traits→ Option 2.

 

Question 68

Among the different recurrent selection schemes, in all practical situations, the superior one was:

1. RSGCA
2. RSSCA
3. RRS
4. SRS

Correct Answer: 3

Explanation:

• RRS (Reciprocal Recurrent Selection)– Considered superior for improving both GCA (General Combining Ability) and SCA (Specific Combining Ability) simultaneously in two populations. It is widely used in cross-pollinated crops for hybrid development.
• RSGCA– Recurrent selection for GCA.
• RSSCA– Recurrent selection for SCA.
• SRS– Simple recurrent selection.
• Therefore, the correct answer is RRS→ Option 3.

 

Question 69

Which species of sugarcane contributed mainly for Nobilization?

1. Saccharum robustum
2. spontaneum
3. sinense
4. barbieri

Correct Answer: 2

Explanation:

• Nobilization– The process of improving sugarcane by crossing noble cane ( officinarum) with wild species to impart hardiness and disease resistance.
• Saccharum spontaneum– The wild species that contributed hardiness, vigor, and disease resistance to cultivated sugarcane through nobilization.
• robustum– Another wild species, less used.
• sinense– Thin-stemmed cultivated type.
• barbieri– Not a standard sugarcane species.
• Therefore, the correct answer is  spontaneum→ Option 2.

 

Question 70

One of the following species of Arachis is a tetraploid with 2n=40:

1. Arachis batizocoi
2. cardenasii
3. monticola
4. villosa

Correct Answer: 3

Explanation:

• Cultivated peanut (Arachis hypogaea)is an allotetraploid with 2n = 40.
• Among wild species, Arachis monticolais a tetraploid (2n=40) and is considered the closest wild relative of cultivated peanut.
• batizocoi, A. cardenasii, A. villosa– Diploid species (2n=20).
• Therefore, the correct answer is  monticola→ Option 3.

 

Question 71

Various by-products are obtained from sugar industry and one of the following is used in manufacture of paper and wall boards:

1. Press mud
2. Molasses
3. Bagasse
4. Trash

Correct Answer: 3

Explanation:

• Bagasse– The fibrous residue left after extracting juice from sugarcane. It is used in the manufacture of paper, wallboards, and biofuel.
• Press mud– Used as a soil amendment (filter cake).
• Molasses– Used for alcohol/rum production, animal feed.
• Trash– Sugarcane tops and leaves, used as mulch or fuel.
• Therefore, the correct answer is Bagasse→ Option 3.

 

Question 72

One of the following millet’s florets are edulcide with anthers bearing hairs at its tip:

1. Pennisetum glaucum
2. Eleusine coracana
3. Setaria latifolia
4. Panicum sumatrense

Correct Answer: 1

Explanation:

• Pennisetum glaucum(pearl millet / bajra) – Florets are edulcide (sweet) and anthers have hairs at the tip.
• Eleusine coracana(finger millet) – Inflorescence is digitate, anthers not hairy.
• Setaria latifolia(foxtail millet) – Dense panicle, not hairy.
• Panicum sumatrense(little millet) – Open panicle.
• Therefore, the correct answer is Pennisetum glaucum→ Option 1.

 

Question 73

One of the following pulses processes monoadelphous stamens:

1. Cajanus cajan
2. Vigna radiata
3. Cicer arietinum
4. Glycine max

Correct Answer: 1

Explanation:

• Monoadelphous stamens– Stamens united into a single group by their filaments.
• Cajanus cajan(pigeon pea / red gram) – Has monoadelphous stamens (9 + 1, but fused into one group).
• Vigna radiata(green gram) – Diadelphous (9 + 1).
• Cicer arietinum(chickpea) – Diadelphous.
• Glycine max(soybean) – Diadelphous.
• Therefore, the correct answer is Cajanus cajan→ Option 1.

 

Question 74

The causal organism for Wart disease of potato is:

1. Synchytrium endobioticum
2. Protomyces macrospores
3. Albugo candida
4. Claviceps purpurea

Correct Answer: 1

Explanation:

• Wart disease of potato– Caused by the fungus Synchytrium endobioticum (a chytridiomycete). It produces warty, cauliflower-like outgrowths on tubers.
• Protomyces macrospores– Causes stem gall on coriander.
• Albugo candida– Causes white rust of crucifers.
• Claviceps purpurea– Causes ergot of rye.
• Therefore, the correct answer is Synchytrium endobioticum→ Option 1.

 

Question 75

The end of the potato tuber which is attached to the stolon is called:

1. Rose end
2. Heel end
3. Basal end
4. Stalk end

Correct Answer: 2

Explanation:

• Heel end– The end of the potato tuber that was attached to the stolon (the underground stem connecting the tuber to the mother plant). It is also called the stem end or attachment end.
• Rose end– The opposite end (apical end) with more eyes.
• Basal end, stalk end– Not the standard terms.
• Therefore, the correct answer is Heel end→ Option 2.

 

Question 76

An approach to farming that combines the best of traditional methods with modern technology, to achieve high productivity with a low environmental impact is:

1. Organic farming
2. Intensive farming
3. Integrated farming
4. Collective farming

Correct Answer: 3

Explanation:

• Integrated farming– An approach that combines traditional and modern methods (crop production, livestock, aquaculture) to achieve high productivity, resource efficiency, and low environmental impact.
• Organic farming– Avoids synthetic inputs, but not necessarily combines modern technology.
• Intensive farming– High inputs, high productivity, but high environmental impact.
• Collective farming– Cooperative farming, not specifically about combining methods.
• Therefore, the correct answer is Integrated farming→ Option 3.

 

Question 77

The process of uptake and storage of carbon by trees and other plants absorbing carbon dioxide and releasing oxygen is called:

1. Carbon sink
2. Carbon sequestration
3. Circulation of carbon
4. Oxygen farming

Correct Answer: 2

Explanation:

• Carbon sequestration– The process of capturing and storing atmospheric carbon dioxide (CO₂) by plants (through photosynthesis) and other natural or artificial systems.
• Carbon sink– A reservoir that stores carbon (e.g., forests, oceans).
• Circulation of carbon– The carbon cycle.
• Oxygen farming– Not a standard term.
• Therefore, the correct answer is Carbon sequestration→ Option 2.

 

Question 78

A farming method which aims to plough the soil as little as possible, to prevent erosion, save energy and improve biodiversity:

1. Conservation headland
2. Conservation Reserve Program
3. Zero tillage
4. Conservation tillage

Correct Answer: 4

Explanation:

• Conservation tillage– A farming method that reduces the intensity of tillage (including no-till, reduced tillage, mulch tillage) to prevent soil erosion, save energy, improve soil health, and enhance biodiversity.
• Zero tillage– A type of conservation tillage (no soil disturbance), but the question describes the broader method.
• Conservation headland– A specific practice at field edges.
• Conservation Reserve Program– A US government program to remove environmentally sensitive land from production.
• Therefore, the correct answer is Conservation tillage→ Option 4.

 

Question 79

The process by which bacteria in the soil break down nitrogen compounds and form nitrates which plants can absorb is:

1. Nitrifier
2. Nitrification
3. Nitrogen fixation
4. Nitrogen leaching

Correct Answer: 2

Explanation:

• Nitrification– The biological process by which soil bacteria (e.g., Nitrosomonas, Nitrobacter) convert ammonia (NH₃) to nitrite (NO₂⁻) and then to nitrate (NO₃⁻) , which plants can absorb.
• Nitrifier– The bacteria themselves, not the process.
• Nitrogen fixation– Conversion of N₂ to NH₃.
• Nitrogen leaching– Loss of nitrates from soil by water.
• Therefore, the correct answer is Nitrification→ Option 2.

 

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.