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💡 Farming with copies
If a mango tastes perfect, a farmer does not want a lottery of seedlings — they want that exact tree, again and again. Vegetative methods make identical copies on demand.
How is vegetative propagation helpful in agriculture?
Methods Used in Agriculture
Cutting — grow a plant from a cut shoot or stem Grafting — join a stem onto a rooted plant Layering — bury a twig till it roots, then cut Tissue culture — grow plantlets from shoot-tip cells
- It produces genetically identical plants, so desirable qualities are kept.
- Scientists and horticulturists use cutting, grafting, layering and tissue culture .
- These methods let farmers efficiently propagate plants and cultivate desirable crops on a large scale .
NCERT Question 9 — A farmer wants to produce
A farmer wants to produce a large number of genetically identical plants quickly. Suggest suitable reproduction methods and explain why they are effective.
View Answer →
NCERT Question 7 — Why do vegetatively propagated plants
Why do vegetatively propagated plants tend to be more vulnerable to diseases than sexually reproduced plants?
View Answer →
Activity 11.1 — Let us explore
In this Activity, we will explore the technique of cutting by preparing shoot cuttings and planting them to grow new plants.
Activity 11.1 — Cutting
Step 1
Take shoot cuttings in the morning
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Step 2
Remove leaves from the lower half
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Step 3
Plant at a 45-60° angle in soil with compost
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Step 4
Water regularly and watch for roots
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New plants grow, identical to the parent
- Interact with gardeners or farmers and observe cutting, grafting and layering; record your observations.
- Collect cuttings of the shoots in the morning for planting.
- Remove leaves from the lower half of each cutting.
- Insert the cuttings up to about half their length in soil mixed with compost, at an angle of about 45–60° from the surface (Fig. 11.2).
- Water them regularly and observe the change, if any.
What we observe
The planted cuttings develop roots and grow into
new plants
that are identical to the parent — a simple method of vegetative propagation.
What is grafting?
- A healthy rooted plant ( Plant A ) is joined to a stem piece of another variety ( Plant B ).
- A slit or wound is made on a twig of Plant A, and the cutting of Plant B is fitted into it (Fig. 11.3).
- The join is protected until it heals; Plant B then grows on the roots of Plant A.
What is layering?
- A flexible thin twig of a tree or shrub (such as lemon) is chosen.
- Its middle part is buried in the soil while still attached to the parent (Fig. 11.4).
- After 10–15 days roots develop on the buried part; the rooted twig is then cut off to grow as a new plant.
🌎 Bridging Science and Society
- Krishi Vigyan Kendras (KVKs) work under ICAR across India.
- They give farmers vocational skills in modern grafting.
- This helps them grow high-yield fruits.
- Farmers also learn marketing strategies and government programmes.
- Together these boost the farmers’ income.
🌎 Bridging Science and Society
- Tissue culture has revolutionised farming, as in banana farming.
- Healthy plantlets are mass-produced from the shoot tip (apical meristem).
- This helps eliminate virus-infected plants.
- It ensures high yields for the farmer.
- It is an example of asexual reproduction in plants.
Budding in Yeast and Hydra
💡 A bump that becomes a body
Watch a yeast cell under a microscope and you may spot a little bump growing out of it — a bud. Hydra do the same, sometimes wearing several buds at once.
Activity 11.2 — Let us explore
In this Activity, we will explore reproduction in yeast by observing budding cells under a microscope.
Activity 11.2 — Yeast
Step 1
Add yeast to warm sugar solution
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Step 2
Keep it warm to activate the yeast
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Step 3
Put a drop on a slide with a coverslip
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Step 4
Observe under a compound microscope
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Buds appear on yeast cells → budding
- Take 20 mL of sugar solution (1 g in 10 mL) in a test tube.
- Add a pinch of yeast granules and place a cotton plug on the mouth of the tube.
- Keep it undisturbed in a warm place to let the yeast become active.
- After 1–2 hours, place a small drop of the mixture on a glass slide and mount it with a coverslip.
- Observe the slide under a compound microscope at different magnifications and draw a diagram of what you see.
What we observe
Small, round
outgrowths (buds)
emerge from the parent yeast cells (Fig. 11.6) — showing that yeast reproduces by budding.
What is budding?
Budding
A bud grows on the parent body, enlarges and separates to live on its own. Seen in yeast and hydra
- Repeated cell division at a specific site produces a small outgrowth called a bud .
- The bud enlarges and separates from the parent to live independently.
- This is called budding ; in hydra, many buds can grow on the parent’s body at the same time (Fig. 11.7).
Reproduction by Spores and Mitosis
💡 Fuzz on the bread
Leave a moist roti in a warm, dark corner and by the third day it wears a fuzzy patch. Those are moulds — fungi that arrived as invisible spores drifting in the air.
Activity 11.3 — Let us experiment
In this Activity, we will experiment to grow bread mould and observe how fungi reproduce by forming spores.
Activity 11.3 — Bread Mould
Step 1
Moisten bread and place in a moist chamber
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Step 2
Keep it warm and dark, and moist
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Step 3
Observe daily for three days
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Step 4
Stain a bit of mould and view it
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Spore-bearing mould grows on the bread
- Lightly moisten a small slice of bread or a roti with a few drops of water.
- Prepare a moist chamber: line a box with wet cotton and tissue paper, and place the bread on it.
- Keep the chamber in a warm, dark place away from direct sunlight, keeping it moist.
- Observe the bread daily without touching it; after three days look for mould with a magnifying glass.
- With a needle, transfer a little mould to a slide, add cotton-blue stain, observe under the microscope and compare with Fig. 11.8.
What we observe
Thread-like structures with round sacs of tiny
spores
grow on the bread — the mould reproduces by forming huge numbers of spores.
How do fungi reproduce by spores?
- Fungi such as Rhizopus and Aspergillus form spores in a sac-like structure or on a swollen vesicle (Fig. 11.8).
- Spores are light, usually single-celled and produced in huge numbers (millions from one colony).
- They float in air currents and, on reaching a moist, nutrient-rich spot, germinate quickly into new individuals.
Why are the offspring of asexual reproduction called clones?
- The central process behind asexual reproduction is mitosis .
- Mitosis produces two daughter cells with the same number of chromosomes , identical to the parent cell.
- So the offspring are genetically identical to the parent and are called clones ; this is a fast way to increase numbers when conditions are favourable.
NCERT Question 4 — Why does asexual reproduction produce
Why does asexual reproduction produce offsprings that are genetically identical to the parent?
View Answer →
🧵 Threads of Curiosity
- We kept the moist chamber warm, about 25–35 °C.
- Mould spores in the air need warmth and moisture.
- Lower temperatures slow or stop their reproduction.
- That is why we refrigerate perishable food.
- Before refrigerators, fresh food lasted only 1–2 days.
🌎 Bridging Science and Society
- Moulds look unpleasant, but fungi benefit society greatly.
- They grow fast by forming spores.
- They degrade organic wastes and pollutants.
- They even help remove heavy metals from industrial wastes.
- Many antibiotics (penicillin, amoxicillin) come from fungi, saving lives.
- Do you know any fungus that can degrade plastic?
✅ Test Yourself
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Which type of reproduction needs only one parent?
Show Answer
Asexual reproduction — the offspring are genetically identical. -
Name three methods of vegetative propagation used in farming.
Show Answer
Cutting, grafting and layering (tissue culture too). -
What is budding?
Show Answer
A small outgrowth forms on the parent, enlarges and separates — as in yeast and hydra. -
How does bread mould reproduce?
Show Answer
By forming huge numbers of light spores that float through the air. -
Which cell division lies behind all asexual reproduction?
Show Answer
Mitosis — it makes two identical daughter cells, so the offspring are clones .
Important Definitions
- Asexual reproduction — reproduction involving a single parent, producing genetically identical offspring.
- Vegetative propagation — new plants arising from the vegetative parts (roots, stems, leaves) of a plant.
- Cutting — growing a new plant from a cut piece of shoot or stem planted in soil.
- Grafting — joining a stem piece of one plant onto a rooted plant so they grow as one.
- Layering — burying part of a twig until it roots, then cutting it to grow as a new plant.
- Tissue culture — growing many plantlets from shoot-tip cells in the laboratory.
- Budding — a bud grows on the parent body, enlarges and separates to live independently.
- Spore — a light, usually single-celled reproductive unit of fungi that germinates into a new individual.
- Mitosis — cell division giving two daughter cells identical to the parent cell.
- Clone — an offspring genetically identical to its single parent.
Important Definitions
- Vegetative propagation — growing a new plant from a vegetative part — a root, stem or leaf — of the parent.
- Cutting — planting a cut piece of shoot in soil so that it grows roots and becomes a new plant.
- Grafting — joining a stem piece of one plant into a slit on the rooted stem of another so the two grow together.
- Layering — burying the middle of a flexible twig in soil until it roots, then cutting it free as a new plant.
- Tissue culture — growing many identical, disease-free plantlets in the laboratory from a tiny piece of a plant.
