- Reproduction is the biological process of producing cew organisms. Living beings are capable of producing organisms of their own kinds.
Types:
- Asexual Reproduction: It is the reproduction without the formation of gametes in which the new organisms are formed from some part of parent body.
- Sexual reproduction: It is the reproduction by the fusion of male and female gametes.
Asexual Reproduction:
Fission: Amoeba, Paramecium, Chlaymydomonas Di-atoms
Budding: Yeast, Hydra
Fragmentation and Regeneration: Spirogyra, Marchantia, Tapeworm, Planeria
Sporulation: Mucor, Fern
Vegetative Propagation: The process of forming new plants by cutting sowing or grafting of any parts of a plants like roots, leaves etc is called vegetative propagation.
Vegetative Propagation:
By leaf: Bryophyllum, Begonia
By root: Dahlia, Sweet potato
By stem: Potato, Ginger
Advantages:
- Seedless plants can continue their generation
- It is quick and easy
- It preserves endangered species
Disadvantages:
- It results in overcrowding
- No genetic variation
- More prone to diseases
REASONABLE FACTS
1. A sexual reproduction is advantageous to farmers.
Ans- A sexual reproduction is advantageous to farmers because,
a. It is easier, cheaper and faster method of reproduction.
b. The plants which do not produce viable seeds (like: rose, sugarcane, bamboo, potato, banana etc) can easily be produced by asexual reproduction.
c. The plants produced by vegetative propagation beer flowers and fruits easier then those produced from seeds.
2. Sexual reproduction plays a very important role in making the no. of chromosomes diploid in offspring.
Ans- In sexual reproduction gametes are produced which possess haploid no. of chromosomes and fertilization takes place which involves fusion of male and female haploid gametes to make the diploid zygote. So, sexual reproduction plays a very important role in making the no. of chromosomes diploid in offspring.
3. Cross fertilization does not occur in closed flowers.
Ans- In the closed flowers, the female reproduction part and male reproductive part are present. So, the transfer of the pollen grains from the another to stigma is occurred within the some flowers. So, cross fertilization does not occur in closed flower.
4. The fertilization in fishes is called external fertilization.
Ans- In the case of fishes the male releases the sperms and female releases ovum. Which got fused externally outside the body of female. So, fertilization in fishes is called external fertilization.
5. Living things reproduce.
Ans- Living things reproduce their own kinds to maintain the life of their species on the earth.
6. Vegetative propagation by stem (rose) is more beneficial than other types of reproduction.
Ans- Vegetative propagation by stem is more beneficial than other types of reproduction due to the following reasons:
– A large no. of plants can be grown by this method.
– The plants which do not produce viable seeds like rose, sugarcane, potato, etc. can be easily produced by this method.
– The plants produced by this method bear flowers and fruit earlier than these produced from seeds.
7. Vegetative propagation by leaf (e.g. bryophyllum) is the asexual method of reproduction.
Ans- Vegetative propagation by leaf (e.g. bryophyllum) is the asexual method of reproduction because no gametes are formed and fused to produce new plants.
9. The fertilization in flowering plants is called double fertilization.
Ans- The fertilization in flowering plants involve the fusion of two male gametes separately i.e. one male gamete with the egg cell (ovum) and the another male gamete with the secondary nucleus. So the fertilization in flowering plants is called double fertilization.
10. Offspring produced by asexual and sexual reproduction process are dissimilar.
Ans- In asexual reproduction, identical offspring to the parents are formed due to absence of crossing over but the crossing over takes place in sexual reproduction that results re-shuffling of genetic material. Hence, variation occurs in offspring so offspring produced by asexual and sexual reproduction process are dissimilar.
