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Sexual and asexual reproduction are two different process of reproduction through which a new organism is produced which is done by the transmission of genetic material from one generation to another. Moreover, the reproduction process is done by the living organisms in order to perpetuate the next generation. Thus, it helps in increasing their population and maintaining life on this planet.
Asexual Reproduction
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The organisms which reproduce only by one organisms is known as asexual reproduction. In this reproduction, organisms reproduce through mitotic divisions resulting in the birth of offspring that are identical to their parents. In other words, an ordinary cell body undergoes cellular divisions, leading to a new individual.
Types of Asexual Reproduction in Animals
Below are given some the ways by organisms may reproduce asexually
Asexual Budding
Asexual budding is similar to fission except for the division of cytoplasmic organisms which is not equal. In this a new individual arises from a bud or grown up from their parents. This asexual reproduction has been found in multicellular organisms like yeasts in which the cell does not divide into two cells instead it reproduce two cells, one is parental cell and another a small daughter cell.
Asexual Budding in Hydra
Fission Reproduction
The process in which a single cell is divided into two equal halves is called fission reproduction. This is the most common type of asexual reproduction among unicellular organisms like bacteria. Fission is the result of mitotic divisions of the nucleus in which a new individual is reproduced by breaking the parents' cells into two equally sized daughter cells.
Binary Fission in Bacteria
Fragmentation
The process of reproduction in which a new organism is formed by the splitting of their parents' cells into two or more parts. It is mostly found in multicellular organisms such as marine worms, starfish (echinoderms).
Fragmentation
Along with this there are different types of asexual reproduction like budding of hydra, parthenogenis, spore formation, vegetative formation and many more.
Sexual Reproduction
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The process of combination of two reproductive cells to produce a new individual is known as sexual reproduction. This is the result of mitotic divisions of germ cells which lead to the production of two haploid gametes: ova and sperm. They involve each other to form two sets of chromosomes or a zygote. It is divided by mitotic divisions to produce a new organism.
Sexual Reproduction
The sexual reproduction is done by two different multicellular organisms divided into two categories
- Germ Cells: The cells which give rise to gametes (cells which combine in sexual reproduction to form new organisms) are called germ cells.
- Somatic cells: All the cells of the body other than germ cells are called somatic cells.
Difference between Sexual and Asexual Reproduction
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The asexual reproduction involved between one parents whereas the sexual reproduction requires the involvement of two parents. This is the basic difference of sexual and asexual reproduction. Below we have the difference of asexual reproduction and sexual reproduction on various parameters.
| Parameters | Asexual Reproduction | Sexual Reproduction |
|---|---|---|
| Meaning | It is process in which a new organisms is developed by the involvement of only one parent | The kind of reproduction where there is an involvement of one or two parents |
| Gamete formation | Does not occur | Occurs |
| Sex organs | It doesn't form any sex organs | It forms sex organs |
| Zygote | The zygote doesn't form | Zygote formation occurs due to fusion of gametes |
| Found In | Lower organisms | Higher invertebrates and all vertebrates |
| Fertilization | Occurred | Does not occur |
| Inheritance | Offspring inherits the characteristics of both parents | Offspring inherits the characteristics of only one parent |
| Cells | Germ cells are involved | Parents somatic cells are involved |
| Cell Division | Mitosis type of cell division occurs | Both Meiosis and mitosis type of cell division |
| Offspring | Two or more | One or two |
| Progeny | Parents are genetically similar | Genetically different parents |
| Example | Fragmentation, bacterial fission, spore formation, etc | Syngamy, external fertilization, conjugation |
Points to Remember
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- Sexual and Asexual Reproduction is a part of Unit 2 World of Living chapter 8 How do Organisms Reproduce.
- It carries a total of 12 to 14 periods and 5 to 6 marks.
- Sexual and Asexual Reproduction both help in the maintainance of generations of the organisms.
- Organisms born through sexual reproduction have a better chance of survival since they contain the DNA of two different parents.
- In asexual reproduction only one parent is involved and offsrings are exact copy of their parent known as clones.
Sample Questions
Ques 1. What can reproduce sexually or asexually? (1 mark)
Ans. Aphids, slime molds, sea anemones, some species of starfish (by fragmentation), and many plants etc are some of the examples of organisms which can reproduce both sexually and asexually.
Ques 2. What are 5 types of asexual reproduction? (1 mark)
Ans. There are various types of asexual reproduction such as binary fission, fragmentation, parthenogenesis, budding, vegetative propagation, spore formation (sporogenesis), and apomixis.
Ques 3. Why is sexual reproduction better than asexual reproduction? (2 marks)
Ans. The sexual method of reproduction is better than the asexual mode. Sexual reproduction gives variety in the hereditary makeup of the posterity. This is because of the mix of qualities from two distinct people. Nonetheless, this isn't the situation with asexual reproduction since only one parent is involved.
Ques 4. What are disadvantages of asexual reproduction? (2 marks)
Ans. The disadvantage of asexual reproduction is that it restricts the evolutionary interaction. The posterity that is made through this cycle is for all intents and purposes indistinguishable from the parent, quite often having a place with similar animal varieties.
Ques 5. What is the process of Budding hydra? (2 marks)
Ans. The hydra reproduces asexually by producing buds in the body wall. Due to repeated cell division on the body leads to the development of a bud as an outgrowth. It mainly occurs when it is fully matured. After maturation, the offspring detach himself from the parent body.
Ques 6. What do you mean by sporangium? (1 mark)
Ans. The spores are formed mainly by the budding process. Fungi are developed by spore formation and the spores contained within the structure of the body is known as sporangium.
Ques 7. What is Vegetative Propagation? (2 marks)
Ans. The process in which plants reproduce asexually through the means of its roots, stems and leaves are known as vegetative propagation. The parent parts of the plant will be useful to produce a new plant species instead of its seeds. Bananas, sweet potatoes, cassava, and pineapple are some examples of vegetative propagation.
Ques 8. What is a Zygote and its importance in the cycle of reproduction in humans? (2 marks)
Ans. A Zygote is the association of the sperm cell in and the egg cell. It is also known as a fertilized ovum, the zygote starts as a single cell however isolates quickly through the course of mitosis soon after fertilization. The zygote is enriched with the qualities from two guardians, and in this way it is diploid(carrying two arrangements of chromosomes). Zygote fills in as an essential link ensuring species continuation from the present to the next generation.
Previous Year Question
Ques 1. Draw a labelled diagram in the proper sequence to show budding in hydra. (2019)
Ans.
Ques 2. Write one main difference between the asexual and sexual mode of reproduction. Which species is likely to have comparatively better chances of survival, the one reproducing asexually or the one reproducing sexually ? Give reasons to justify your answer. (2018)
Ans. In asexual reproduction only one parent is involved and the offsprings are identical to their parents known as clones.
In sexual reproduction two parents are involved and the offsprings are different from their parents.
Offsprings produced through sexual reproduction have a better chance of survival than when produced through sexual reproduction.
Babies produced through sexual reproduction will have the DNA of both the parents as two parents are involved in the reproduction procedure, hence will have better adaptability capacity.
Ques 3. Name the method by which spirogyra reproduces under favourable conditions. Is this method sexual or asexual? (2017)
Ans. Through the process of fragmentation which is an asexual method of reproduction spirogyra reproduces.
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