Class 8 Reproduction in Plants

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  1.  Reproduction means producing young ones of the same kind.
  2. In asexual reproduction, only one parent is involved.
  3. In sexual reproduction, two parents are involved.
  4. Budding is common in yeast.
  5. Spirogyra reproduces using fragmentation.
  6. Vegetative propagation can be either natural or artificial.
  7. The vegetative parts that give rise to new plants are called propagules.
  8. Ginger, potato, onion reproduce by stem.
  9. Bryophyllum reproduces by leaf.
  10. Sweet potato reproduces by root.
  11. The flower is the reproductive part of a plant.
  12. Stamens are the male reproductive parts of the flower.
  13. Carpels are the female reproductive parts of the flower.
  14. Lotus and Trapa are aquatic plants but they are pollinated by insects.
  15. Name two organisms in which one cell divides into 4 daughter cells.
    a) Chlorella
    b) Chlamydomonas
  16. What are the two types/modes of reproduction in plants?
    a) Asexual reproduction
    b) Sexual reproduction
  17. What is binary fission?
    In this method, the nucleus splits into two and then the cell splits to form two small daughter cells.
  18. What is budding?
    In this method, the parent cell produces a bud that grows and gets detached from the parent body to lead an independent life.
  19. What is fragmentation?
    In this method, one filament grows and breaks off into two or more fragments. Each fragment then grows into an individual.
  20. What is spore formation?
    Some plants and fungi bear spores that are light and can be carried away by wind or insects to different places. On suitable conditions, spores germinate to give rise to new plants.
  21. What is vegetative reproduction?
    In some plants, certain parts like leaf, stem, root are capable of giving rise to new plants. This is vegetative reproduction.
  22. Why is carrot known as a biennial plant?
    Because in the first year goes in root development and energy storage, and the second year goes in flowering, seed formation, and death.
  23. What are the advantages of vegetative reproduction?
    a) Reproduction takes place in a shorter time.
    b) New plants spread very fast in a small area.
    c) It is a surer method of propagation.
    d) The good characteristics of mother plant are retained by the daughter plants.
  24. What are the disadvantages of vegetative reproduction?
    a) They are likely to be affected simultaneously if a disease spreads in the farm.
    b) Dispersal of seeds does not take place on its own.
  25. Explain cutting.
    The stem is cut into small pieces with each bearing an axillary bud. The cut ends are planted in moist soil. After a few days, they grow into new plants. Example: rose, china rose, lemon, sugarcane.
  26. Explain layering.
    A portion of the lower branches of a plant with an axillary bud is bent down to the ground so that it touches the soil. A ring of bark is removed from this portion, which is then covered with soil. In a few days, when the branch gives out roots, it is cut off from the main plant. Example: mint, rose, jasmine.
  27. What is grafting?
    A small shoot of a plant is intimately fixed on the stem of another plant of the same or related species. The grafted points are bound together with tape. In a few days, the new cells develop and a new plant grows. Example: rose, mango, guava.
  28. What is micro-propagation?
    The tissue of suitable part of the plant is used as an explant. The explants are sterilized to prevent microbial growth and then cultured in a particular nutrient medium. Cells grow and divide to form a cell mass called callus. Some growth regulators are also added. The callus grows into a tiny plant called plantlet. After few weeks, the plantlets are transferred to the soil. Example: Gladiolus, Chrysanthemum.
  29. What are the benefits of plant tissue culture technique?
    a) Provides rapid propagation of identical individuals.
    b) Useful in cases where seeds are dormant.
  30. What are the limitations of tissue culture?
    a) Requires scientific expertise.
    b) Cannot be applied in all cases.
    c) Not easily applicable in remote agricultural areas.
  31. Name the 4 whorls of the flower.
    a) Calyx
    b) Corolla
    c) Androecium
    d) Gynoecium
  32. What is pollination?
    It is the process in which the pollen grains from the anthers are transferred to the stigma of a flower of the same species.
  33. What is self-pollination?
    It is a pollination that occurs either within the same flower or between two flowers on the same plant.
  34. What is cross pollination?
    It is a pollination that occurs between two flowers on different plants of the same species.
  35. What are the agents of cross pollination?
    a) Insects
    b) Wind
    c) Water
  36. What is fertilization?
    It is the fusion of the male cell with the female cell to produce a zygote.

Location: India

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