Friday, November 23, 2012

7th Reproduction in plants solved Questions,

7th Reproduction in plants solved Questions,MCQ,For Summative assessments

1.What is meant by reproduction?

Ans: The process of producing new individuals of same kind of the same species is called reproduction.

2. Why reproduction is a essential life process?

Ans: Reproduction is essential for continuation of the species from generation to generation.

3. What are the different modes of unisexual reproduction?

Ans: modes of reproduction evolve only one parent is called unisexual reproduction.
(a) Fission: The mode of reproduction in which unicellular organism split into two equal halves and produce new ones is called binary fission. For example amoeba and bacteria
(b) Fragmentation: The mode of reproduction in which body of plant breaks up into smaller fragments and each fragment grows into a new individual is known as Fragmentation e.g. Spirogyra , algae
(c) Budding: The mode of reproduction in which small buds when develop get separated and mature into new organisms is called Budding. E.g. Yeast, Hydra, Bryophyllum
(d) Spore formation: The mode of reproduction takes place by means of spores is called spore algae and fungi
The spores are covered by thick walls that protect them until they come into  contact with another moist surface and can begin to grow.

4. Mention some of the spores of asexual reproduction.

Ans:  Aplanospores, Zoospores, Akinetes and Conidia

5. What do you mean by vegetative propagation?

Ans:  Vegetative propagation is the ability of plants to reproduce by using vegetative parts like root ,stem and leaves is called vegetative propagation.

6.  Why there are so many methods of reproduction?

Ans:  It is due to complexity of the body design of organisms.

7.What is sexual reproduction?

Ans:  Sexual reproduction is the process in which two components ( male and female) are involved to produce offspring of their own kind.

8. Name the reproductive organ of a flowering plant

Ans: The flower is a reproductive organ of a flowering plant

9. Name the male and female part of flower.

Androecium is the male part of a flower,and Gynoecium is the female part.

Androecium is a group of stamens. Each Stamen consists of a stalk called the filament and a small bag like structure called the anther at the tip. The pollen grains are contained in the anther within the pollen sacs

Gynoceium is the female part of the flower and consists of the carpels or ovary. 

Gynoceium has three parts 
1) Stigma 
2) Style and 
3) Ovary. 
The ovary contains the ovules and each ovule carries within it an embryo sac, within which lies the egg cell or the female gamete.

10.How does sexual reproduction take place in flowering plants?

Ans:  The sexual reproduction in flowering plants involves
1. Pollination 2. Fertilization
Transfer of pollen grains from the anther to the stigma is called pollination.
Pollen grains are transferred mainly by wind, water and insects. They are called as pollinating agents.
The fusion of a male gamete with egg is known as fertilization. The fertilized egg is known as zygote which develops into embryo.

11.Why are there so many varieties of fruits?

Fruits develop by many ways so there are many varieties of fruits. For example, some fruits develop without the act of fertilization. Such fruits are called arthenocarpic fruits. E.g. seedless grapes, guava, mango etc.

12.Explain different parts of flower?

Ans: Following are the parts of flowers:
a)Sepal: Green leafy part of flower that protect flower in bud condition.
b) Petal: Coloured leafy part of flower that attract insect for pollination
c) Stamen: The male parts of flower that contain pollen grain
d)pistil: The female parts of flower that contain ovary at bottom
what are the various methods of vegetative propagation?

13.Explain three artificial  methods of Vegetative Propagation

Ans:  Cutting: Here the cuttings of the "parent" plant are removed and placed in a suitable environment so that they can grow into a whole new plant. For example rose cutting.
Layering: The stem is bent down and the target region buried in the soil. The buried part of stem develops roots and is detached from the plant and develops into new plant.
Grafting: In grafting a shoot or bud of a selected, desired plant (scion) is grafted onto the stock of another type of plant.
Plant tissue culture: Tissue culture is the artificial method of reproduction where a small cutting of plant such as root or stem is taken and is grown in laboratory condition by providing it with suitable nutrients in a media and growing them in a petri plate or test tubes. The plant is provided with the most hygienic condition.

14. What are the various methods of vegetative propagation?

  • Vegetative Propagation by Roots- Eg. Dalbergia sissoo (Shishan) 
  • Vegetative Propagaton by Stem- Eg. Banana
  • Vegetative Propagation by Leaf- Eg. Bryophyllum.
  • Cutting- Eg. Sugarcane
  • Grafting- Eg. Desi Mango
  • Budding- Eg. Rose
  • Layering- Eg. Jasmine
  • Micropropagation or Tissue Culture- Eg. Dahlia
15.What are the advantages of vegetative reproduction?

Ans:  a) It allows them to produce new plants quickly without any reproductive organs.
b) The plants produced by this method are exact copies of the parent plant
c) New varieties of plants having required characteristics can be developed by this method.

16.How is zygote formed in plants?

Ans:  When male gamete present in pollen grain moves into ovules and fuse with female egg cell inside ovules and zygote is formed .This process is called fertilization.

17.What are the different types of pollination found in flowering plants?

Ans: Pollination is of two types. They are
1. Self pollination: The transfer of pollen grains from the anther of a flower to the stigma of the same flower or another flower of the same plant is known as self pollination or autogamy.
2. Cross pollination: The transfer of pollen grains of a flower to the stigma of another flower of a different plant of the same species is called cross pollination or allogamy

18. What is the roll of pollen grains in flowering plants?

Ans: Male gametes are produced inside pollen grains.

19.How does fertilization occur in flower?

Ans:  After pollination pollen grain germinate on the stigma and moves through style to reach into ovules and fuse with female gamete. Thus fertilization occur.
Where and how are seeds formed in plants?
In side ovary, the ovule develops into seed. As seed form, the ovary increases in size and became fruit.

20. Name two kinds of gametes in flower?

Ans: Pollen grain and egg cell

21. What are pollen grains

Ans: Male reproductive cell

22.What is found in embryo sac

Ans: Female reproductive egg cell

23. Name the plant form colonies by budding?

Ans: Duckweed or hydra

24. Why are spore formed?

Ans: Spores are formed to help over coming unfavorable condition for reproduction

25. How is Bryophyllum plants propagated?

Ans: By leaves

26. How does spirogyra reproduce?

Ans: Fragmentation

27. What is grafting ?

Ans : Grafting is a method of vegetative propagation in which two parts of two different plants are joined together in a specific manner so that they unite to grow as one plant.

28.What is 'scion' ?

Ans : The portion of the plant which is grafted on other plant is called scion.

29.What is 'stock' ?

Ans : The plant on which grafting is performed is called stock.

30.Fill in the blanks

(a) Pollination by animals and birds is known as --------------

Ans: Zoophily.

(b) Pollination by birds is called ----------------

Ans: Ornithophily

(c) The egg cell or the female gamete lies within ----------------

Ans: embryo sac

(d) Flowers pollinated by wind are called -----------------

Ans: Anemophilous

(e) The Pollination by Water is known as ----------------------


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