Q.Write two uses of tissue culture.
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🔒 Start your 14-day free trial to unlock the full solution →Concept understanding — Meristem Culture
Let’s start with something you already know. When you prune a rose bush or cut the tip off a mint plant, it doesn’t die — it grows back, often bushier. That happens because plants keep a reserve of “baby cells” at their growing tips. These cells are called meristematic cells, and they are the plant’s version of stem cells: undifferentiated, ever-dividing, and capable of turning into any part of the plant.
Now, Meristem Culture is a laboratory technique where you take a tiny piece of that growing tip (the meristem) and grow it in a sterile, nutrient-rich medium. The goal is to produce a whole new plant from that tiny piece — a clone of the original. It’s a form of micropropagation, but with a special twist: the meristem is usually free of viruses, so the new plant is also virus-free.
Meristem culture is the only reliable method to produce virus-free plants from an infected parent plant. This is because viruses cannot reach the actively dividing meristem cells — they travel through the plant’s vascular tissue, which the meristem lacks.
Here’s why this matters in agriculture and horticulture:
- Disease elimination: Many cash crops (potato, sugarcane, banana, cassava) accumulate viruses over generations. Meristem culture lets farmers start with clean stock.
- Rapid multiplication: A single meristem can yield thousands of identical plants in a year — far faster than traditional cuttings or seeds.
- Conservation: Rare or endangered plant species can be multiplied without harming the parent plant.
- Uniformity: All plants are genetically identical (clones), so they flower, fruit, and respond to fertilisers at the same time — ideal for commercial farming.
The NCERT textbook (Class 12 Biology, Chapter 9 — Strategies for Enhancement in Food Production) mentions meristem culture under tissue culture and specifically highlights its use in producing virus-free plants. The textbook example: sugarcane and banana are routinely cleaned of viruses using this method.
Meristem culture is not the same as ordinary tissue culture. In ordinary tissue culture, you can use any part of the plant (leaf, stem, root). In meristem culture, you specifically use the shoot apical meristem — the dome of cells at the very tip of a growing shoot. That’s what makes it virus-free. …
Tissue culture is the growing of cells, tissues or whole plants on a nutrient medium under sterile conditions; because a single explant can regenerate a whole plant (totipotency), it has powerful practical uses. …
Tissue culture uses: (1) rapid micropropagation of many identical, healthy plants from one explant; (2) production of virus/disease-free plants (and somatic hybrids like pomato) — plus germplasm conservation.
Concept
Tissue culture is the technique of growing plant cells, tissues or organs on a sterile nutrient medium (with the right salts, sugar and growth hormones like auxin and cytokinin). It works because plant cells are totipotent — a single cell can regenerate an entire plant.
Two uses
- Micropropagation (clonal propagation): thousands of genetically identical plantlets (somaclones) can be produced in a short time from a tiny piece of tissue — used commercially for banana, orchids, tomato, apple, etc.
- Production of disease/virus-free plants: culturing the apical/axillary meristem (which is usually virus-free) gives healthy, disease-free plants even from an infected parent — important in banana, sugarcane and potato. …
- CBSE 2026Set ANNUAL1 markQ.Write answer in one word/sentence: In tissue culture the capacity of generate a whole plant from any cell / explant is called ______.
›Reveal solutionSolution
The ability of a cell/explant to form a whole plant is called totipotency.
In plant tissue culture, a small part of a plant (an explant) or even a single cell can be grown on a suitable nutrient medium and made to develop into a complete, whole plant. The inherent capacity of a plant cell to give rise to an entire or …
- CBSE 2025Set 57/4/11 markMCQQ.For Questions number 13 to 16, two statements are given – one labelled as Assertion (A) and the other labelled as Reason (R). Select the correct answer to these questions from the codes (A), (B), (C) and (D) as given below. (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A). (B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A). (C) Assertion (A) is true, but Reason (R) is false. (D) Assertion (A) is false, but Reason (R) is true. Assertion (A) : The meristems are grown 'in vitro' to obtain virus-free plants from an infected plant. Reason (R) : If the plant is infected with a virus, the roots and the stems are free of virus.
›Reveal solutionSolution
The assertion is true, but the reason given is false — meristems are grown in vitro to obtain virus-free plants, but it is the shoot apical meristem, not roots and stems generally, that remains virus-free.
The technique of growing meristems in culture — what we call meristem culture — is one of the most elegant applications of plant tissue culture. When a plant is infected with a virus, the virus spreads through most of the plant's tissues via the vascular system. However, the shoot apical meristem, the tiny dome of actively dividing cells at the very tip of a growing shoot, often remains virus-free. Why? Because meristematic cells divide so rapidly that the virus cannot keep up, and they lack the well-developed vascular connections that viruses use to travel. So by excising that tiny meristem tip and growing it on a sterile nutrient medium (in vitro), we can regenerate a whole plant that is free from the virus.
Now look at the assertion: "The meristems are grown 'in vitro' to obtain virus-free plants from an infected plant." This is exactly what the NCERT textbook describes. It is a standard, widely used method in horticulture and agriculture to produce healthy stock from diseased parent plants — for example, in potatoes, bananas, or sugarcane. …
- CBSE 2025Set 57/5/11 markMCQQ.For Questions number 13 to 16, two statements are given – one labelled as Assertion (A) and the other labelled as Reason (R). Select the correct answer to these questions from the codes (A), (B), (C) and (D) as given below. (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A). (B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A). (C) Assertion (A) is true, but Reason (R) is false. (D) Assertion (A) is false, but Reason (R) is true. Assertion (A) : To generate only a part of the plant from a cell is totipotency. Reason (R) : Suitable special nutrient media and sterile conditions are required in 'in vitro' conditions for the division of cells in explants.
›Reveal solutionSolution
Totipotency is the ability of a cell to generate an entire organism, not just a part; the assertion is false. The reason correctly describes requirements for tissue culture, so it is true but cannot explain a false assertion. The correct option is (D).
The question tests two distinct concepts in plant tissue culture: the definition of totipotency and the technical requirements for in vitro culture. Understanding what totipotency actually means is crucial here.
Totipotency refers to the capacity of a single cell to divide and differentiate into all cell types of an organism, ultimately regenerating a complete, functional plant. This property is most famously demonstrated in plant cells, where a single somatic cell (say, from a leaf or root) can be cultured to produce an entire new plant with roots, stems, leaves, flowers — the works. The term comes from totus (Latin for "whole") + potency (power), emphasizing the ability to form the whole organism.
The assertion claims totipotency means generating "only a part of the plant," which is the exact opposite. Generating only a part — say, callus tissue, or roots alone, or shoots alone — would be examples of pluripotency or multipotency, not totipotency.
Now let's evaluate each statement:
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Assertion (A): "To generate only a part of the plant from a cell is totipotency."
This is false. Totipotency is the ability to regenerate the entire plant, not just a part. If a cell can only form a specific tissue or organ, it is not exhibiting totipotency.
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Reason (R): "Suitable special nutrient media and sterile conditions are required in 'in vitro' conditions for the division of cells in explants."
This is true. Tissue culture (in vitro culture) absolutely requires:
- Nutrient media containing sugars, minerals, vitamins, and plant growth regulators (auxins, cytokinins) to support cell division and differentiation. …
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- CBSE 2019Set ANNUAL1 markMCQQ.'Pomato' is a somatic hybrid between –(a)(i) Potato and Tomato(b)(ii) Tomato and Poppy(c)(iii) Potato and Cotton(d)(iv) Tomato and Banana
›Reveal solutionSolution
'Pomato' is a somatic hybrid of Potato and Tomato — option (i) — made by fusing their protoplasts (somatic hybridisation).
Concept
In somatic hybridisation, the cell walls of two different plant cells are digested with enzymes to obtain naked cells (protoplasts), which are then fused to form a hybrid protoplast. This is grown in culture into a whole hybrid plant, combining characters of both parents without sexual reproduction.
Why potato + tomato
- The protoplasts of potato and tomato were fused to create the somatic hybrid nicknamed "Pomato" (bearing potato tubers below and tomatoes above, in principle). …
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