Life Process || Reproduction || asexual and sexual reproduction || fragmentation || vegetative propagation
Ans: The biological process in which living organism produce their own kinds by sexual and asexual method is called reproduction.
2. List the types of reproduction.
Ans: There are two types of reproduction. They are:
i) Sexual Reproduction
ii) Asexual Reproduction
3. Define asexual reproduction with its example.
Ans: A type of reproduction which takes place from a single parent without the fusion of male and female gametes, is called asexual reproduction. For an example: tapeworm, amoeba, star fish, etc. reproduce by this process.
4. Mention any three features of asexual reproduction.
Ans: The following are the features of asexual reproductions:
i) The produced offspring is genetically similar to its parents.
ii) Only one organism is involved in asexual reproduction.
iii) Mitosis cell division occurs during asexual reproduction.
5. List the different modes of asexual reproduction in plants? Name an organism that reproduces by each mode?
Ans: The list of different modes of asexual reproduction is plants are given below:
a) Fission : Chlyamydomonas
b) Budding : Yeast
c) Fragmentaton : Spirogyra
d) Sporulation : Fern
e) Vegetative propagation : Dahlia
6. Define the following with two examples each.
a) Fission:
Fission is a method of asexual reproduction, which mainly occurs in unicellular organisms. In this method, an organism divides into two approximately equal parts when it gets matured. This process is called binary fission. And in some organisms, large number of daughter cells are formed from a single mother cell under unfavourable condition, which is termed as multiple fission.
For example: In amoeba, bacteria, etc. reproduction takes place by binary fussion.
In Plasmodium and Chlamydomonas reproduction takes place by multiple fission.
b) Budding:
The method of asexual reproduction which takes place by the formation of bud is called budding. Thus, in this process small outgrowth froms at one side of an organism called bud, and division takes place. The divided nucleus of parents migrate towards the bud. Moreover, the bud enlarges its size and later detaches from parent body which ultimately grows into new daughter organism.
For example: hydra and yeast.
7. What is fragmentation? Describe the process with two examples.
Ans: The method of asexual reproduction in which a multicellular organism breaks into two or more fragments and each fragments develops into a new complete organism is called fragmentation.
This process takes place due to different factors like heat, wind, etc. This process is also called regeneration because when an organism divides into two parts, the mother organism can also replace its lost part.
For example: Spirogyra, tapeworm, etc. reproduce by this process.
8. Define sporulation with suitable examples.
Ans: The type of asexual reproduction, which takes place by means of spores is called sporulation. Sporangium of flowers consist numbers of small, unicellular reproductive structure called spores. When this sporangium gets matured it bursts and these spores germinate into new plants under favorable conditions. This process occurs mainly in non-flowering plants like mushroom, mucor, fern, etc.
9. What is vegetative propagation? Why is it useful to farmers?
Ans: Vegetative propagation is the method of asexual reproduction in which new plants are produced by cutting, sowing or grafting of the vegetative parts of the plants like stem, root or leaf. For example: bryophyllum potato, mint, dahlia, etc. reproduce by this process.
Vegetative propagation is very useful to farmers because it is cheap and rapid method. The plants produced by vegetative propagation bear flowers and fruits earlier than those produced from seeds. For example: orange, mango, etc.
10. Mention any three advantages of vegetative propagation.
Ans: The following are the three advantages of vegetative propagation:
i) It is rapid method of propagation in plant and is cheap.
ii) It gives rise to genetically uniform population.
iii) Plants which are produced from vegetative propagation bear flowers and fruits earlier than those produced from seeds.
11. Amoeba is immortal. Explain.
Ans: Amoeba reproduces asexually by binary fission under favorable conditions. The amoeba divides into two identical parts when it gets matured. And under unfavorable condition a thick covering called cyst is formed around the cell, and a number of nuclei is formed from a single nucleus. And on return of favorable condition, the cyst burst and the number of nuclei formed before now forms a separate amoeba. Thus, amoeba is not dead even under unfavorable condition, which means there is no natural death of amoeba, it may die only accidentally. So, amoeba is immortal.
12. List out the advantages of asexual reproduction.
Ans: The following are the advantages of asexual reproduction:
i) It is rapid and cheap method as it does not require male and female gametes.
ii) New organism produced are identical to the parents thus large number of organism can be produced having similar characteristic.
13. “Tapeworm is a hermaphrodite.” Explain.
Ans: Hermaphrodites are those organisms which bear both male and female reproductive organs. As tape worm has both male and female reproductive organs, it is a hermaphrodite.
14. Define sexual reproduction with some example.
Ans: A type of reproduction, which takes place by the fusion of male and female gametes is called sexual reproduction.
15. Mention any three characteristics of sexual reproduction.
Ans: The following are the three characteristics of sexual reproduction:
i) Both male and female take part in sexual reproduction.
ii) Offsprinbg produced exhibit both the characteristics of male and female.
iii) Meiosis cell division is followed by mitosis cell division.
16. Differentiate between unisexual and bisexual animals.
Ans: The following are the difference between unisexual and bisexual animals:
| Unisexual Animal | Bisexual Animal |
| Animals having only one sex organ i.e. either male sex or female sex organ is termed as unisexual animal. | Animals having both male and female sex organs is termed as bisexual animals. |
| For example: Frog, man, crow, monkey, etc. | For example: Earthworm, hydra, tapeworm, leech, etc. |
17. Differentiate between binary fission and multiple fission.
Ans: The following are the difference between binary fission and multiple fission:
| Binary Fission | Multiple Fission |
| When an organism is fully matured, it is divided into two daughter organisms. This process is called binary fission. | The fission in which a parent organism splits into two or more than two daughter organism at same time is called multiple fission. |
| It occurs in favorable condition. | It occurs under unfavorable conditions. |
| It does not form cyst. For example: amoeba, diatoms, etc. reproduce through binary fission. | It forms cyst. For example: plasmodium, chlamydomonas, etc. reproduce through multiple fission. |