Reroduction in Plants

REPRODUCTION IN PLANTS

1)What will happen if there will be a day when no trees will be left on earth?

Ans) No living being will be able to survive, there will be no rains, therefore no water, therefore no life.

2) How important is therefore the existence of plants on earth?

Ans) It is the most  important and integral part of earth, which aids the existence of all the other forms of life.

 3) Do you think that all the plants and trees that we see in our surroundings are the ones that were born during the origin of earth?

Ans) No

 If no, what must have been the aid for the re-growth of the plants?

Ans)By the  means of seeds, flowers, stem, roots, spores.

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--Reproduction- Giving birth to new offspring

-In case of plants, producing new plants is reproduction in plants.

--In some plants, new plants can be grown with the help of roots, stems, flowers, fruits, seeds and leaves. This form of reproduction is called as vegetative reproduction.  While most plants reproduce by the means of seeds.

® Some plants reproduce by producing spores.

- Among the seed bearing plants, the flowering plants dominate the non flowering.

PARTS OF THE FLOWER:

Petals: Often brightly coloured in order to attract birds and insects.

Sepals: Holds the petals and other parts of the flower.

These are small leaf like structures,

®  green in colour

®  at the base of the flower

®  protects the flower when it is in bud stage

®  form an outermost layer calyx

Stamen: Anther and the filament that holds the anther

®  stamen forms the male part of the flower

--The female part of the flower  is called as pistil or carpel.

® Pistil is composed of three parts

  Stigma- lies at the top and is sticky and has coarse surface

 ®  Style- holds the stigma and is hollow tube that reaches the base of the flower

®  Ovary-lies at the base and forms the core of the flower, tube of the style opens into ovary.

Parts of flower: 

à Stigma

à  Style

à  Ovary

à  Anther

à  Filament

à  Petal

à  Sepal

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4) Name the reproductive parts of the flower?

 Ans) Pistil and stamen.

5) What happens to the anther of the flower?

Ans)  It is carried to the stigma of the same or another flower of same type. 

6) How is the stigma of the flower useful in the process?

Ans)  After the anther  reaches the stigma the anther moves inside the tube like structure- style of the stigma, in order to reach the ovary.

7) How does the pollen and the ovary together form the seed?

 Ans) The ovule  present inside the ovary fuses with the pollen and fertilisation takes place that gives rise to the seed. 

8) What type of pollination is it when the pollen of one flower is transferred to  the stigma of another flower of same type?

Ans) Cross pollination 

9) What type of pollination is it when the pollen of the flower is transferred to the stigma of the same flower?

Ans) Self pollination

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Pollination is the process by which pollen is transferred from the anther to the stigma of the plant.

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The requirements of a seed in order to grow into a healthy plant: 

®  right type of soil

®  right amount of water

®  oxygen

®  sunlight

®  temperature

-- After everything is available to the seed in right proportions, the seed starts developing- this process is called germination.

10) What will happen if the seed is sowed in right kind of soil?

Ans) It will not grow properly or will not grow at all. 

11) What will happen if we over water a plant?

 Ans) The soil will get eroded or the seed will rot and therefore the plant will not grow.

12) What does a seed requires for growing?

Ans) Right kind of soil, right amount of water, right temperature, oxygen, sunlight

13)  What helps in pollination of a flower?

Ans) Wind, insects, animals.

---Seeds travel to places by natural forces that help them to reach to distinct places and grow there,

  this is called as seed dispersal.

14) Name the seeds shown in the visualiser.

 Ans) Coconut, dandelion, cocklebur, cucumber, apple 

15) Which out of the five seeds is the heaviest?

 Ans) Coconut 

16) Which out of the five seeds is the lightest in weight?

 Ans) Dandelion 

17 )What is the special characteristic of the cocklebur seed that makes it different from others?

 Ans) It has a rough/ has tiny spine like structures on its surface. 

18) How does this special feature of the seed help it in dispersal by animals?

 Ans) It helps the seed to cling on the animal body.

19)  How the hair like whorl on the dandelion seed helps it to disperse through wind?

Ans) It gives the seed the flight and remain in air, till it reaches the right place.

20)  Where do apples grow?

Ans )In orchards

 21) Do you think that wind or water dispersal is possible for these seeds?

 Ans) NO 

Why?

 Ans) Wind - because it is inside the fruit, therefore cannot fly in air, unless  open;

          Water- because apples do not grow near water bodies.