#plant tissue culture

ZOOLOGY

Which plant tissue culture technique is used for large-scale plant propagation?

Micropropagation is used for large-scale production of genetically identical plants. This follows from latest NCERT 2026-27 principle explaining the concept clearly for NEET students in simple steps as per rationalized syllabus.

Ref: NCERT Biology Textbook - Latest Edition for Academic Session 2026-27 (Zoology section, Rationalized Textbook for Class XI and XII), Chapter: Biology - Zoology portion (Latest NCERT Textbooks for Academic Session 2026-27 - Rationalized Edition for Class XI and XII), Topic: Structural organization, ph

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ZOOLOGY

Which component in tissue culture media provides energy to growing plant lls?

Sucrose provides the energy required for the growth and development of plant lls in tissue culture media. This follows from NCERT principle where the relation explains the outcome clearly for students in simple steps.

Ref: NCERT Biology Textbook for Class XI and XII (Zoology section), Chapter: Structural Organisation in Animals and Frog, Topic: Tissues, skeletal and organ systems.

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ZOOLOGY

Which nutrient in plant tissue culture media provides energy for ll growth?

Sucrose provides the energy required for the growth and development of plant lls in tissue culture media. This follows from NCERT principle where the relation explains the outcome clearly for students in simple steps.

Ref: NCERT Biology Textbook for Class XI and XII (Zoology section), Chapter: Structural Organisation in Animals and Frog, Topic: Tissues, skeletal and organ systems.

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Plant tissue culture 3

Hairy roots show which characteristic?

Phenotype of transformed roots reflects activity of rol genes integrated into nuclear genome. rolA, rolB, rolC alter auxin perception and secondary metabolism. Roots exhibit lack of strong positive geotropism, grow plagiotropically or ageotropically on agar, and display prolific lateral branching due to diminished apical dominance and enhanced pericycle activation. Branch tips are covered with dense root hairs, increasing surface area. Growth occurs without exogenous auxin on hormone-free medium, showing hormone autotrophy, and biomass accumulation is rapid, doubling every 2 to 3 days in liqui

Ref: Nilsson 1997 rolB auxin sensitivity; Casanova Trends Plant Sci 2005 morphology; NCBI NBK21344; https://doi.org/10.1016/j.tplants.2005.08.004 hairy root branching review.

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Plant tissue culture 3

Friable callus is mainly used to initiate:

Texture of callus determines suitability for liquid systems. Compact nodular callus consists of tightly packed cells cemented by calcium pectate, resistant to dispersal. Friable type arises when pectin methylesterase activity reduces middle lamella cohesion, producing crumbly masses of loosely associated, highly vacuolated cells with large intercellular air spaces. Upon transfer to agitated liquid Murashige-Skoog medium containing 2,4-D, these fragments break easily into single cells and small aggregates under 100 micrometer diameter, forming homogeneous suspension. Such suspensions exhibit ex

Ref: Murashige & Skoog 1962 friable callus; Street Plant Tissue 1977 suspension initiation; Dodds & Roberts Experiments 4th ed; NCBI NBK26844 cell suspensions texture importance.

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Plant tissue culture 3

Habituation in callus culture refers to:

Normal plant cell proliferation requires exogenous auxin to activate S-phase genes and cytokinin to induce mitotic cyclins. Habituation denotes acquired ability to divide without these supplements due to stable metabolic reprogramming. Prolonged culture selects variants overproducing cytokinins via isopentenyl transferase genes or auxins via YUCCA flavin monooxygenases, or mutations conferring constitutive signaling through type-B response regulators and auxin receptors TIR1. Epigenetic changes in promoter methylation lock these biosynthetic genes in active state, making trait heritable throug

Ref: Gautheret 1955 habituation; Meins & Binns PNAS 1979 hormone autotrophy; Taiz Plant Physiology Ch 21 cytokinin autonomy; NCBI NBK218342 habituation concept review.

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Plant tissue culture 3

One method to reduce somaclonal variation is:

Minimizing dedifferentiation reduces accumulation of chromosomal instability. Callus phase involves disorganized rapid mitosis under influence of potent synthetic auxin, creating opportunities for endoreduplication, transposon mobilization, and methylation drift. Each additional subculture multiplies these errors. Direct regeneration circumvents callus by activating axillary meristems, adventitious shoot formation from epidermal cells, or direct somatic embryogenesis on explant surface using balanced cytokinin to auxin ratio. Because organized meristems divide less frequently and maintain tigh

Ref: Bhojwani & Razdan Plant Tissue Culture 2015 Ch 10 direct organogenesis; Thorpe In Vitro Embryogenesis; NCBI PMC7469045 reducing somaclonal variation; Murashige & Skoog direct regeneration.

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Plant tissue culture 3

Herbicide-resistant somaclonal variants are detected by:

Herbicide resistance is a positive selectable trait best confirmed through functional challenge. Somaclonal populations contain rare cells with modified target enzymes such as glyphosate-insensitive EPSP synthase, acetylated phosphinothricin via PAT, or amplified glutathione S-transferases conferring detoxification. Plating callus or cell suspensions onto medium supplemented with discriminating concentration of respective herbicide imposes lethal pressure, killing wild-type cells by blocking aromatic amino acid synthesis or glutamine synthetase, causing ammonia toxicity. Only resistant clones

Ref: Chaleff & Raytbauer Science 1985 herbicide selection; PubMed 24254045 in vitro selection; NCBI NBK131103 selection systems; Bhojwani herbicide resistance screening.

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Plant tissue culture 3

Somaclonal variants can be detected using:

Comprehensive identification of somaclones demands multi-level screening, since variation manifests from visible morphology to DNA sequence. Whole-plant evaluation in greenhouse notes leaf shape, plant height, flowering time, flower color, and vigor, providing first indication of off-types. Cytological examination extends analysis to nuclear level, measuring chromosome number, polyploidy, anaphase bridges, and micronuclei after fixation and acetocarmine staining of actively dividing root tips. Molecular level assessment employs electrophoretic tools: isozyme SDS-PAGE reveals altered enzyme mob

Ref: Bhojwani & Dantu Plant Tissue Culture Ch 12 detection; NCBI PMC403111 somaclonal markers; IntechOpen Molecular electrophoresis; https://www.ncbi.nlm.nih.gov/books/NBK218342/

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Plant tissue culture 3

Which is NOT a cause of somaclonal variation?

Causes of somaclonal variation encompass genetic epigenetic disruptions triggered by tissue culture environment, but pollination mechanism is unrelated because in vitro regeneration occurs without sexual fertilization. Authentic causes include gene mutations from replication errors under rapid division error prone repair under oxidative stress, chromosome number changes aneuploidy polyploidy due to spindle abnormalities c mitosis endoreduplication induced by culture hormones colchicine like effects, structural rearrangements translocations deletions from DNA strand breaks, activation of dorman

Ref: Kaeppler 2000 somaclonal causes transposons; NCBI causes methylation mutation.

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Plant tissue culture 2

Colchicine is used in plant tissue culture mainly to:

Colchicine is used in plant tissue culture mainly to induce polyploidy and chromosome doubling rather than as fusogen or wall digesting agent. Alkaloid isolated from Colchicum autumnale binds tubulin dimers preventing polymerization into microtubules forming mitotic spindle fibers during metaphase. Without functional spindle, sister chromatids fail to separate at anaphase, nuclear membrane reforms enclosing doubled chromosome complement leading to endoreduplication tetraploid or doubled haploid formation. Application involves treating haploid plantlets derived from androgenesis gynogenesis or

Ref: Blakeslee & Avery 1937 colchicine polyploidy; Dhooghe et al., Plant Methods antimitotic.

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Plant tissue culture 2

Osmotic stabilizers such as mannitol are required to:

Osmotic stabilizers such as mannitol sorbitol glucose at 0.3 to 0.7 molar act as essential protectants preventing protoplast bursting after cell wall removal because wall normally provides mechanical resistance counterbalancing internal turgor pressure generated by high intracellular solute concentration. Without rigid wall plasma membrane alone insufficient to resist water influx driven by lower external water potential, protoplasts swell and lyse within minutes, destroying preparation. Non metabolizable sugar alcohol mannitol provides iso osmotic environment matching cell sap osmolarity abou

Ref: Kao & Michayluk 1975 osmotic stabilizer; Plant Cell Culture protoplast methods.

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