Frank Brothers Solutions for ICSE Class 9 Biology Chapter 5 Vegetative Propagation

PAGE NO : 49

Solution 1:
(i) Cutting - In this method, stems are cut into pieces and planted in the soil. This is the easiest and most frequently used method of artificially propagating plants, Eg. - Sugarcane, grapes, rose etc.
(ii) Layering - Here, an intact branch is bent into the soil and is covered with moist soil. The growing tip remains above the soil. When roots arise in the branch region in contact with soil, it is separated from the parent plant. Within a few weeks, a new plant can be propagated by this method. Eg. - Cherry, jasmine and grapevine
(iii) Grafting - Here a detached part of one plant called scion, is inserted into the stem of a rooted plant called stock. Scion is a short piece of detached shoot containing several buds. Stock is the lower portion of the plant fixed in the soil. The scion is cut and placed face to face with stock. After a few days, vascular connection is established between the joined parts and parenchyma tissue develops at the junction of the graft. Eg. - Apple, pear, mango, guava.
These artificial methods allow us to grow new plants from parts of the parent plant like stems or branches. They are widely used in agriculture and gardening because they produce new plants much faster than growing them from seeds.
Teacher's Tip: In Grafting, remember "Scion" is the top part (starts with 'S' for Sky) and "Stock" is the bottom part (starts with 'S' for Soil).
Exam Tip: Draw simple labeled diagrams for layering and grafting to demonstrate a clear understanding and earn full marks.

Solution 1 (iv):
Budding - Here a single bud instead of a branch is grafted on the stock. In about two weeks, the bud unites with the stock after which the stock just above the bud is cut off. Eg. - Lemon and hibiscus
Budding is a specialized form of grafting where only one bud is used to create a new plant variety. This method is highly effective for fruit trees to ensure consistent fruit quality across an entire orchard.
Teacher's Tip: Budding is basically "mini-grafting" using a single "eye" or bud instead of a large twig.
Exam Tip: Always mention that budding is most successful when performed during the rainy season when the plant's sap is flowing freely.

Solution 2:
Advantages of vegetative propagation are:
1. Vegetative propagation is the only method to obtain new plants in those plants where seed formation does not occur.
2. This method is cheaper, convenient and rapid method of plant multiplication.
3. It is the only method of reproduction in plants like grapes, roses, pineapple etc. which do not form viable seeds.
4. Plants raised through vegetative propagation from a single plant form a genetically uniform population called a clone.
This process is very beneficial for farmers because it creates "clones," meaning every new plant is an exact copy of the parent. It allows for the quick mass production of crops that might otherwise take years to grow from seeds.
Teacher's Tip: Remember the word "Clone" to help you recall that the offspring are genetically identical to the parent.
Exam Tip: Use the term "genetically uniform" when discussing clones to show scientific precision in your answers.

Solution 3:
(i) Cutting - In this method, stems are cut into pieces and planted in the soil. This is the easiest and most frequently used method of artificially propagating plants, Eg. - Sugarcane, grapes, rose etc.
(ii) Layering - Here, an intact branch is bent into the soil and is covered with moist soil. The growing tip remains above the soil. When roots arise in the branch region in contact with soil, it is separated from the parent plant. Within a few weeks, a new plant can be propagated by this method. Eg. - Cherry, jasmine and grapevine
(iii) Grafting - Here a detached part of one plant called scion, is inserted into the stem of a rooted plant called stock. Scion is a short piece of detached shoot containing several buds. Stock is the lower portion of the plant fixed in the soil. The scion is cut and placed face to face with stock. After a few days, vascular connection is established between the joined parts and parenchyma tissue develops at the junction of the graft. Eg. - Apple, pear, mango, guava.
These techniques are essential for propagating high-value plants that do not produce seeds easily. By using these methods, we can preserve the best characteristics of a plant, such as sweet fruit or beautiful flowers.
Teacher's Tip: Think of "Cutting" as a simple transplant and "Layering" as a plant doing a push-up into the dirt.
Exam Tip: For Grafting questions, emphasize that the "vascular connection" must be established for the graft to be successful.

Solution 3 (iv):
Budding - Here a single bud instead of branch is grafted on the stock. In about two weeks, the bud unites with the stock after which the stock just above the bud is cut off. Eg. - Lemon and hibiscus
Budding is a very efficient way to multiply plants because it uses very little material from the donor plant. It is commonly used to produce citrus fruits like lemons and oranges with reliable traits.
Teacher's Tip: The T-shaped slit is the signature cut used for inserting the bud in this method.
Exam Tip: Provide examples like "Lemon" and "Hibiscus" to ensure you receive full credit for your answer.

Solution 4:
Orchids, Rose
Roses and orchids are popular choices for artificial propagation because they are difficult to grow uniformly from seeds. Using these methods ensures that every flower in a garden has the exact same color and fragrance.
Teacher's Tip: Think of these as "Luxury Flowers" that need special propagation care.
Exam Tip: If asked for examples of decorative plants that use these methods, Rose and Orchid are the best standard answers.

Solution 5:
Plants propagated through root cuttings are:
1. Roses
2. Raspberries
3. Blackberries
4. Crabapple
5. Fig
6. Lilac
Plants propagated through stem cuttings are:
1. Blackberries
2. Cannabis
3. Grapes
4. Pineapple
5. Sugarcane
(Write any four of each)
Root cuttings involve taking a part of the root system to grow a whole new organism, whereas stem cuttings use pieces of the branch. Both methods rely on the plant's ability to regenerate its entire body from just a small fragment.
Teacher's Tip: Stem cutting is much more common in daily gardening than root cutting.
Exam Tip: When a question specifies "Write any four," list them clearly with numbers to make your answer easy for the examiner to read.

Solution 6:
(a) Budding - Here a single bud instead of a branch is grafted on the stock. In about two weeks, the bud unites with the stock after which the stock just above the bud is cut off. Budding is usually done in rainy season. Budding is carried out in plants like lemon and hibiscus.
(b) Grafting - Here a detached part of one plant called scion, is inserted into the stem of a rooted plant called stock. Scion is a short piece of detached shoot containing several buds. After a few days, vascular connection is established between the joined parts and parenchyma tissue develops at the junction of the graft. Examples of plants in which grafting is carried out are apple, pear, mango and guava.
(c) Layering - In layering, an intact branch is bent into the soil and is covered with moist soil. The growing tip remains above the soil. When roots arise in the branch region in contact with soil, it is separated from the parent plant. Within a few weeks, a new plant can be propagated by this method. Examples of plants in which layering is carried out are cherry, jasmine and grapevine.
These three methods are the most common "artificial" ways people help plants reproduce. They are vital tools for horticulturists who want to improve crop yields and produce beautiful ornamental gardens.
Teacher's Tip: Remember: Budding uses one bud, Grafting uses a shoot (Scion), and Layering stays attached to the parent until roots grow.
Exam Tip: Use the specific vocabulary from the definitions, like "Scion" and "Stock," to demonstrate a deep understanding of the subject.

Solution 7:
(a) Tubers
(b) Stem cutting
(c) Bulb
(d) Corm
(e) Stem cutting
These terms identify the specific part of the plant or the exact method used to create a new individual. Understanding these classifications helps in choosing the right way to grow different types of vegetables and flowers.
Teacher's Tip: Tubers (like potatoes) and Bulbs (like onions) are essentially underground storage containers.
Exam Tip: Match "Potato" to "Tuber" and "Onion" to "Bulb" for quick one-mark questions.

Solution 8:
(a) Sugarcane
(b) Agave/ Oxalis
(c) Bryophyllum
(d) Potato
(e) Apple
This list shows the variety of plants that can be grown without using any seeds at all. Bryophyllum is particularly famous because it can grow entire new plantlets right along the edges of its leaves.
Teacher's Tip: Bryophyllum is the "leaf propagation" champion of the plant world.
Exam Tip: If an exam asks for a plant that reproduces via its leaves, Bryophyllum is almost always the answer.

Solution 9:
Hybridisation is the crossing of two plants differing in one or more genetic characters to obtain a new individual or variety.
Hybridization is like "mixing and matching" the best traits from two different parent plants. The goal is to create a "super plant" that might produce more food or resist diseases better than its parents.
Teacher's Tip: Think of hybridisation as plant "engineering" to combine strengths.
Exam Tip: Define it specifically as a cross between "differing genetic characters" for a complete definition.

Solution 10:
Plant hybridisation is a time consuming process and is carried out between two plants of different species or between two varieties of the same species. Two parent plants are selected of which one parent has the desired characters. On the female plant, emasculation is carried out i.e. stamens are removed to prevent undesirable fertilization. Then pollen of the male plant is collected and artificially brushed on stigma of emasculated flower. The emasculated flower is kept bagged before and after fertilization to prevent any unwanted cross pollination. After pollination, fertilization takes place and seeds of desired variety are produced.
Emasculation is a key step because it stops the plant from pollinating itself, allowing the scientist to choose the father. "Bagging" ensures that the wind or insects don't bring in "wrong" pollen from other nearby plants.
Teacher's Tip: Emasculation means removing the male parts (stamens) to leave only the female parts (pistil) active.
Exam Tip: List the steps in order: selection, emasculation, pollination, and bagging to get full marks for the process.

Solution 11:
Vegetative propagation is economically important in the following ways:
1. Vegetative propagation is helpful in the improvement of food crops, cash crops and ornamentals.
2. Plants raised through vegetative propagation are totally identical to the parent plants (clones) and are genetically similar.
3. Vegetative propagation is the only method to multiply those plants where seed formation does not occur.
4. This is a cheaper, convenient and rapid method of plant multiplication.
5. It is the only method of reproduction in plants like grapes, roses, Chrysanthemums, pineapples etc. which do not form viable seeds i.e. seeds do not germinate.
These methods are vital for the economy because they allow farmers to produce food faster and more reliably. It also allows us to enjoy seedless fruits like pineapples and grapes which would be impossible to grow from traditional seeds.
Teacher's Tip: "Rapid" and "Cheap" are the two best words to describe why businesses love vegetative propagation.
Exam Tip: Mention that it is the "only method" for seedless plants to secure full marks on its economic importance.

Solution 12:
The objectives of plant hybridisation are:
1. Development of hybrid vigour
2. Accumulation of desired traits of two or more plants in a single hybrid.
Plant hybridization is beneficial to us in the following ways:
1. It is useful in obtaining clones and genetic experimental plants.
2. It is a quick and convenient method.
3. Hybrid plants are stronger than either parent plant in general and have a higher yield.
4. Crop plants giving a much higher yield can be developed using this technique.
5. Plants resistant to diseases, pests and climatic factors can be produced by hybridization with desired plants or wild species.
6. The hybrid plants (especially ornamentals) have more colourful or fragrant flowers that enhance their commercial value.
Hybrid vigour, also called heterosis, makes the new plant much more robust and productive than its parents. This technique is responsible for many of the high-yielding grains and beautiful garden flowers we see today.
Teacher's Tip: Hybrid Vigour means the offspring is "bigger, better, and faster" than its parents.
Exam Tip: Use the phrase "disease resistant" when discussing the benefits of hybridization to show practical knowledge.

Solution 13:
Micropropagation is a technique of propagating plants by culturing cells, tissues or organs. This technique uses a very small amount of the stock plant.
Micropropagation is the ultimate way to grow thousands of plants from just a few tiny cells in a laboratory. It is also known as "tissue culture" and is used to save endangered species or produce medicine.
Teacher's Tip: "Micro" means tiny - you only need a tiny piece to grow a whole forest!
Exam Tip: Define it as using "cells, tissues, or organs" to ensure scientific accuracy.

Solution 14:
In micropropagation, a piece of tissue such as bud or shoot tip is removed from a plant, sterilized and placed onto a culture medium. The tissue multiplies into an undifferentiated mass of cells called callus. Later it is transferred to a nutrient medium where this tissue differentiates and produces a number of plantlets. The plantlets are then transplanted into pots kept in green houses and then placed in fields to see their performance.
The "culture medium" is like a nutritional soup that gives the tiny cells everything they need to grow into roots and leaves. The "callus" stage is very important because it's when the single cells start to multiply into a large group.
Teacher's Tip: A Callus is like a "blob" of baby cells before they decide to become roots or shoots.
Exam Tip: Remember the sequence: Sterilization -> Culture Medium -> Callus -> Differentiation -> Greenhouse.

Solution 15:
1. (b) layering
2. (c) lack cambium
3. (a) agamospermy
4. (b) both genetically and morphologically similar to parent-plants.
These multiple-choice answers summarize key concepts, such as why monocots cannot be grafted. Monocots lack the "cambium" layer, which is the tissue that acts like glue to fuse two plants together.
Teacher's Tip: "Morphologically" just means they look the same on the outside.
Exam Tip: For MCQ questions, always write both the option letter and the text (e.g., 1. (b) layering) for absolute clarity.