Section outline

    • Q1. Fill in the blanks:

      Ans:

      a. Production of new individuals from the vegetative part of parent is called vegetative propagation.

      b. A flower may have either male or female reproductive parts. Such a flower is called unisexual.

      c. The transfer of pollen grains from the anther to the stigma of the same or of another flower of the same kind is known as pollination.

      d. The fusion of male and female gametes is termed as fertilization.

      e. Seed dispersal takes place by means of wind, water, and animals.

      Q2. Describe the different methods of asexual reproduction. Give examples.

      Ans: 

      The different methods of asexual reproduction are:

      1. Vegetative propagation: In this type of reproduction, new plants are produced from the vegetative parts of the plant like the stems, roots, leaves buds. Eg: tuber of potato, rhizome of ginger
      2. Budding: A small projection called as bud, gradually grows gets detached from the parent cell to form daughter cell. The new daughter cell grows produces more new cells. Eg: yeast.
      3. Fragmentation: in this method the reproduction takes place through breaking down the parent plant into two or more fragments. Each fragment grows into a new plant when sufficient amount of water nutrients are available. Eg: Spirogyra.
      4. Spore formation: in this method reproduction is done by spores which under favourable conditions germinate develop into new plants. Eg: ferns, mosses, fungi
      5. Fission: In this method, a unicellular organism splits to form new organisms. Eg:  Amoeba, plasmodium.
      Q3. Explain what you understand by sexual reproduction.

      Ans: 

      1. Sexual reproduction in plants is formation of new plants by fusion of male female gametes.
      2. Flower is the reproductive organ in this method.
      3. Stamen which consist of filament anther are the male reproductive organs.
      4. Pistil which contain stigma, style ovary are the female reproductive organs.
      Q4. State the main difference between asexual and sexual reproduction.

      Ans:

      Asexual Reproduction Sexual Reproduction
      It requires only one parent. It requires both male & female parents.
      No gametes are required. Gametes are required.
      Seeds are not formed. Seeds are formed.
      New organisms formed  are identical to parent. New organisms formed are not identical to parent.
      Eg: Potato, rose. Eg: Mango, hibiscus.
      Q5. Sketch the reproductive parts of a flower.

      Ans:

      Q6. Explain the difference between self-pollination and cross-pollination.

      Ans:

      Self-Pollination Cross-Pollination
      The pollen grain is transferred to the stigma of the same flower or another flower on the same plant. The pollen grain is transferred to the stigma a flower of a different plant of the same kind.
      Does not depend on pollinating agents. Depends on pollinating agents like water, wind, insects, etc.
      Results in less genetic diversity. Results in more genetic diversity.
      Eg: peas, rice, wheat, etc. Eg: apple, sunflower, coconut, etc.
      Q7. How does the process of fertilization take place in flowers?

      Ans:

      1. Anther contain pollen grains which produce male gametes.
      2. During pollination, the pollen grains reach the stigma of the flower. 
      3. Then a pollen tube is formed which grows down the style to the ovary.
      4. Male gametes are released in the pollen tube which reach the ovule.
      5. The ovule contains female gametes.
      6. The male & female gametes fuse together in the ovule to form zygote.
      Q8. Describe the various ways by which seeds are dispersed.
      1. Wind: Seeds dispersed by wind are smaller in size, lightweight & have wings or hair like structure. Due to this they are easily blown away by the wind. Eg: drumstick, dandelion, maple, etc.
      2. Water: The fruits or seeds of aquatic plant or plants that live near water can be carried away with water as they develop the ability to float & have a spongy or fibrous outer coat. Eg: coconut.
      3. Animals: Animals and birds disperse seeds in many ways. They eat fruits & excrete the seeds away from the parent plant. Some seeds have spines or hooks which get attached to the animals body or fur. Eg: xanthium, urena
      4. Explosion: Some seeds are dispersed when the fruits burst with sudden jerks. Eg: pea, castor, balsam, etc.
      Q9. Match the items in Column I with those in Column II:

      Ans:

      (a) Bud - (iii) Yeast

      (b) Eyes - (v) Potato

      (c) Fragmentation - (ii) Spirogyra

      (d) Wings - (i) Maple

      (e) Spores - (iv) Bread mould

      Q10. Tick the correct answer:

      Ans:

      (a) The reproductive part of a plant is the (iv) flower.

      (b) The process of fusion of the male and the female gametes is called (i) fertilization.

      (c) Mature ovary forms the (iv) fruit

      (d) A spore producing organism is (ii) bread mould

      (e) Bryophyllum can reproduce by its (ii) leaves