SEE Science (Reproduction in plants through spores) Notes

Reproduction in Plants Through Spores

1.     What do you mean by 'alternation of generation' in context of the cycle of fern plant?

Ans: The sporophytic and gametophytic generation of fern plant alternating one after other in a life cycle is called alternation of generation.

2.     Which stages in life cycle of fern plant are called sporophyte and gametophyte? Give reason.

Ans: The fern plant itself is called a sporophyte as it produces spores by asexual reproduction whereas the prothallus is called a gametophyte as it produces male and female gametes.

3.    Name the stage of life cycle of fern plant shown in the diagram. Label the parts A and B. Also write down the functions of part C.

Ans: Prothallus of fern plant is shown in the given diagram this represents the gametophytic generation.

In the figure:

Part A → Archegonia

Part B → Antheridia

Functions of part C i.e. rhizoids:

i) Rhizoids absorb water and minerals from soil.

ii) Rhizoids fix the prothallus in the soil.

 

4.     Draw a neat diagram of prothallus and label its reproductive organs.

Ans:

 

5.    Answer the following questions by studying the given figure.

 

i) What does the figure represent?

Ans: Section of sorus of fern plant.

ii) Label A, B and c. Mention also the function of 'C'.

Ans: In the given figure,

          A→ Covered indusium

          B→ Placenta

          C→ Sporangium

Function of C: Sporangium produces spores.

6.     What is sporangium? Where is it located in a fern plant?

Ans: Sporangium is a tiny sac like structure in which spores are formed in organism. It is       locates inside the spores of a fern plant. 

7.     What type of mushroom is not edible?

Ans: All species of mushroom are not edible. Some black or bright coloured wild                     mushrooms like Amanita Verna, Amanita phalloides, Agaricus silvicola, Amanita               Muscaria etc. are poisonous. So, they are not edible.

8.     Which stage of its life cycle is shown in the following figure? How is this structure developed? What is the number of nucleus in each cell of it? What is produced from its growth?

Ans: Secondary mycelium of mushroom is shown in the given figure. It is formed by the fusion of two primary mycelia of the opposite strain.

9.    Write any two names of edible mushroom.

Ans: Two edible mushrooms:

a)    Agaricus Bisporus

b)    Pleurotus

c)    Agaricus Campestris

d)    Agaricus Brunnescen

10.  What is meant by basidiospore?

Ans: The spore produced by gills of mushroom is called basidiospore.

11.  How many stages is the life cycle of fern plant divided into? What are they?

Ans: Life cycle of fern plant divided into two stages. They are:

a) Sporophytic stage.

b) Gametophytic stage.

12.  Why is mushroom known as a type of fungus?

Ans: Mushroom is a non-green plant. It cannot manufacture its own food. It obtains its own food from dead and decaying organic matter. Therefore, mushroom known as a type of fungus.

13.  Write the name of the plant shown in the diagram. Name A, B and C. what is the function of A?

Ans: Mushroom is shown in the diagram.

        Here, A – Pileus

                  B – Gills

                  C – Stipe

Function of A: It protects the gills.

14.  Which acid is produced by archegonium? What is its function?

Ans: Malic acid is produced by archegonium. Malic acid attracts antherozoids towards archegonium.

15.  What are the functions of mycelium, stipe and gills in mushroom?

Ans: Function of

Mycelium – It absorbs water and nutrients from the soil.

Stipe – It support the pileus.

Gills - It produce basidiospore.

16.  Write any two features of asexual reproduction.

Ans: Features of asexual reproduction are:

a)    There is involvement of a single individual.

b)    It completes in a short period.

c)    It produces new offspring genetically similar to the parent.

d)    In asexual reproduction, gametes are not produced.

17.  Write any two symptoms seen after eating poisonous mushroom.

Ans: Symptoms seen after eating poisonous mushroom are:

a)    Gastric disorder, severe headache and vomiting.

b)    Paralysis of central nervous system.

c)    Causes pain and diarrhea.

19.  Mushroom is known as saprophyte, why?

Ans: Mushroom is known as saprophyte it obtained required nutrients from dead and decaying organic matter.

20.  Through potato is seed bearing plant it reproduced through vegetative propagation, why?

Ans: Through potato is seed bearing plant it reproduced through vegetative propagation because potato does not produce viable seeds.

21.  What is antherozoid?

Ans: A male gamete produced by an antheridium is called antherozoid.

22.  Differences between primary and secondary mycelium.

Primary mycelium	Secondary mycelium
It is formed by the germination of basidiospore.	It is formed by the fusion of two primary mycelium of opposite strain.
It is a thread like structure having uni-nucleated cells.	It is a branched structure having bi-nucleated cells.
It is temporary stage.	It is a permanent stage.

23.  What is fertilization?

Ans: The process in which the nuclei of male and female gametes fuse together is called fertilization.

24.  Differences between internal and external fertilization.

Internal fertilization	External fertilization
The fusion of male and female gametes takes place inside the body of female.	The fusion of male and female gametes takes place outside the body of female.
Mating of male and female is necessary.	Mating of male and female is not necessary.
Water is not required during internal fertilization.	Water is required during external fertilization.
This process is common in reptiles, birds and mammals.	This process is common in frogs and fishes.

25.  Which stage in the fern is called prothallus?

Ans: Gametophytic stage in the fern is called prothallus because it bears gametes i.e. antherozoid and ovum and reproduces sexually.

26.  Write the importance of mushroom.

Ans: The important of mushroom are:

a)    Mushroom is taken as nutritious food because it contains protein, vitamins and minerals in a remarkable amount.

b)    It helps to prevent high blood pressure, blood cholesterol, heart diseases, diabetes, cancer, etc.

c)    It helps to increase the fertility of soil.

d)    It can be used as a cash crop.

27.  In which part of plants pollen grain are produced?

Ans: Pollen grains are produced in anther of androecium.

28.  Write the differences between gamete and zygote.

Gamete	Zygote
It is haploid (n).	It is diploid (2n).
It is formed by gametogenesis.	It is formed after fertilization.

29.  What is binary and multiple fissions?

Ans: The type of asexual reproduction in which a parent body divides into two daughter organism is called binary fissions.

The type of asexual reproduction is which a parent organism splits into more than two daughter organisms is called multiple fission.

30.  Differences between binary and multiple fissions.

Binary fission	Multiple fission
It occurs during favourable condition.	It occurs during unfavourable condition.
It results only two offspring at once.	It results more than two offspring's at once.
No protective coat or cyst is formed around the cell.	A cyst or a protective coat is formed around the cell.