Reproduction in Plants: Asexual MCQs Quiz | Class 10

Reproduction in Plants: Asexual Methods Explained

Reproduction is a fundamental biological process by which new individual organisms – “offspring” – are produced from their “parents”. In plants, reproduction can occur through sexual or asexual methods. Asexual reproduction in plants involves a single parent producing offspring that are genetically identical to itself, without the involvement of gametes or fertilization.

Key Asexual Reproduction Methods in Plants:

1. Vegetative Propagation: This is the most common form of asexual reproduction in plants, where new plants grow from vegetative parts like roots, stems, leaves, and buds.
   • Natural Vegetative Propagation: Occurs naturally in various ways:
     • Stems:
       • Runners/Stolons: Horizontal stems that grow along the ground, rooting at nodes to form new plants (e.g., Strawberry, Grass).
       • Rhizomes: Underground horizontal stems that store food and produce roots and shoots from their nodes (e.g., Ginger, Turmeric).
       • Tubers: Swollen underground stems that store food and have ‘eyes’ (buds) that can grow into new plants (e.g., Potato).
       • Bulbs: Underground modified stems with fleshy leaves that store food (e.g., Onion, Garlic).
       • Corms: Short, swollen underground stems that store food and produce buds (e.g., Gladiolus, Colocasia).
     • Roots: Some plants can develop new shoots from adventitious buds on their roots (e.g., Guava, Sweet potato, Dahlia).
     • Leaves: Leaves of some plants can develop adventitious buds that detach and grow into new plants (e.g., Bryophyllum).
   • Artificial Vegetative Propagation: Methods used by humans to grow plants.
     • Cutting: A part of a stem, root, or leaf is cut and planted, which then develops into a new plant (e.g., Rose, Sugarcane).
     • Layering: A branch of a plant is bent and covered with soil while still attached to the parent plant. Roots develop from the covered part, and then it is cut off to form a new plant (e.g., Jasmine, Lemon).
     • Grafting: Parts of two plants (scion and stock) are joined so that they grow as one plant, combining desirable traits (e.g., Mango, Apple).
     • Tissue Culture (Micropropagation): Growing new plants from small pieces of plant tissue or cells in a nutrient medium under sterile conditions. This allows rapid propagation of many plants (e.g., Orchids, Ornamental plants).
2. Budding: A common method in lower organisms like yeast, but also observed in some simple plants. A small outgrowth or bud develops on the parent body, which then detaches and grows into a new individual.
3. Spore Formation: Many non-flowering plants like fungi (e.g., Bread mould) and ferns reproduce through spores. Spores are tiny, resistant reproductive units that can be dispersed by wind and germinate into new individuals under favorable conditions.
4. Fragmentation: In simpler plants like Spirogyra (an alga), the plant body breaks into two or more fragments, and each fragment develops into a new individual.
5. Fission: In single-celled organisms like bacteria and some algae, the parent cell simply divides into two or more daughter cells.

Advantages of Asexual Reproduction:

• Produces offspring genetically identical to the parent, preserving desirable traits.
• Allows rapid propagation of plants, especially those that do not produce viable seeds.
• New plants mature faster compared to those grown from seeds.
• Requires only one parent.

Quick Revision List:

• Asexual reproduction involves one parent and produces identical offspring.
• Vegetative propagation uses plant parts like roots, stems, and leaves.
• Examples: Potato (tuber), Ginger (rhizome), Bryophyllum (leaves), Strawberry (runner).
• Artificial methods include cutting, layering, grafting, and tissue culture.
• Budding involves an outgrowth developing into a new individual (e.g., Yeast, some simple plants).
• Spore formation is common in fungi and ferns.
• Fragmentation is seen in algae like Spirogyra.

Further Practice Questions:

1. Which part of a potato plant is primarily involved in vegetative propagation?
2. Name two plants that can be propagated by stem cuttings.
3. How does a Bryophyllum leaf reproduce asexually?
4. What is the main difference between natural and artificial vegetative propagation?
5. Explain the process of grafting in brief.