Asexual Reproduction In Animals: Examples, Advantages, Disadvantages
Asexual reproduction is a natural process through which living beings give rise to offspring without two parents involved. One parent is sufficient for such reproduction, and the new organism is normally a replica, or clone, of the parent. Asexual reproduction is found in simple life forms such as bacteria, fungi, algae, and some plants. For example, bacteria reproduce quickly through a method called binary fission, where one cell divides into two identical cells. This helps the population grow rapidly, especially in favourable conditions.
This Story also Contains
- Asexual Reproduction in Animals
- Definition of Asexual Reproduction
- Type of Asexual Reproduction
- Advantages and Disadvantages of Asexual Reproduction
- Ecological and Evolutionary Significance
- Recommended Video on Asexual Mode of Reproduction
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There are various forms of asexual reproduction including budding, fragmentation, spore formation, and vegetative propagation. Budding in sponges and hydra enables a portion of the body to develop into a new organism. Vegetative structures such as stems, roots, or leaves in plants contribute to the formation of new plants, as in the case of potatoes and ginger. Asexual reproduction does not include gametes (egg or sperm cells) and typically is slower and less energy requiring than sexual reproduction.
Asexual Reproduction in Animals
Animals reproduce through either sexual or asexual reproduction. In Zoology, the only mode of reproduction for mammals is sexual reproduction, whereby two different gametes; the male sperm and female egg fuse to form an embryo, and this process takes place within the body of the female reproductive system. Instead, asexual reproduction, which is dominant in plants and microorganisms such as bacteria, requires no gametes. It allows organisms to reproduce independently and very rapidly, and often all offspring are genetically identical to the parent. Unlike the case with sexual reproduction, asexual reproduction does not result in variation among offspring.
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Definition of Asexual Reproduction
Asexual reproduction is defined as the mode of reproduction in which male and female gametes are called sperm and eggs are not involved. This type of reproduction does not need the fusion of male and female gametes.
It does not require the presence of both gametes, that is, male and female gametes
It does not require the fusion of sperm and egg
It takes less time to form offspring
Offspring produced by asexual reproduction grow at a very fast rate
Organisms produced by asexual reproduction are exact copies of each other and also copies of the parent plant.
There is no variation seen in asexual reproduction
Type of Asexual Reproduction
Asexual reproduction occurs in various forms within the animal kingdom. The significant ones include:
Binary Fission
Binary Fission is defined as a mode of asexual reproduction. In this type of reproduction, the entire body of the amoeba divides into her two daughter cells with the help of mitosis. This is an even split. Two divisions exist here. One is the nuclear division called karyokinesis, and the other is the cytoplasmic division called karyokinesis called cytokinesis.
| Type of Binary Fission | Plane of Division | Key Feature | Examples |
|---|---|---|---|
| Longitudinal Binary Fission | Division occurs along the longitudinal plane (lengthwise) | The organism splits from head to tail direction | Euglena |
| Transverse Binary Fission | Division occurs along the transverse plane (across the width) | The organism divides at right angles to its length; parent loses identity | Planaria, Diatoms |
Spore Formation
When unfavourable conditions in the environment, then the amoeba and many fungi, such as Rhizopus reproduce with the help of a process called spore formation.
In this reproduction, breakage of the nuclear membrane takes place, and some of the chromatin blocks get released into the cytoplasm. Each chromatin block formed in the cytoplasm now gets inside the nuclear membrane. These blocks now become small daughter nuclei. This is the most adapted mode of sexual reproduction.
Fragmentation
Fragmentation is defined as the process of asexual reproduction. In this form of reproduction, the lost parts of the organism act and function as new organisms. Spirogyra is an alga with the ability to fragment. H. The Lost Spirogyra part works like one Spirogyra. When a Spirogyra is cut down into two pieces by natural means or accidentally, then its two parts behave as individual cells.
Budding
Budding is defined as a mode of asexual reproduction and can be observed in many organisms. In this type of reproduction, new plants or new individuals develop from the shoot growth itself. This bud detaches from the parent plant and has the property of behaving like a new plant. Buds generally form during the process of cell division. It is A process of nuclear and cytoplasmic division that occurs at specific plant locations. Found in hydra and yeast.
Regeneration
Regeneration is a type of asexual reproduction, organisms retain and redevelop lost parts. An organism that has now evolved the missing part becomes a complete individual. This is seen in the case of planarians.
Parthenogenesis
Parthenogenesis is a type of asexual reproduction, female organisms produce eggs without fertilising the female egg. This is also termed false fertilisation. Lizards and many different insects reproduce by an asexual mode of reproduction.
Advantages and Disadvantages of Asexual Reproduction
Asexual reproduction has both positive and negative impacts that influence how organisms live and propagate. It enables living organisms to give birth quickly without a mate, but it restricts genetic diversity. Asexual reproduction is perfect in constant environments but could be dangerous in a change of conditions. The advantages and disadvantages of asexual reproduction in animals are given below:
- Asexual reproduction facilitates fast population increase.
- It requires a single parent, hence no need to find a mate.
- The process is less energy-intensive than sexual reproduction.
- Offspring are genetic replicas of the parent, keeping successful characteristics intact.
- It is efficient in constant environments where conditions remain unaltered.
- Reduced genetic diversity makes organisms susceptible to disease.
- Offspring can hardly survive if the environment rapidly changes.
- Harmful characteristics can accumulate in the population over time with a lack of variation.
Ecological and Evolutionary Significance
Asexual reproduction has a huge part in the adaptation and survival of species, together with its effects on population dynamics.
Role in Adaptation and Survival
Adaptation to Stable Environments: Asexual reproduction is advantageous in stable environments where the genetic variation of a population is not of prime importance.
Rapid Colonisation: The members of a species can rapidly colonise new environments since the process of reproduction is very fast.
Effects on the Dynamics of Population
Rise in Population: The population can rise rapidly, thus increasing the chance for survival when the conditions are favourable.
Ecological Balance: Asexual reproduction helps in the maintenance of the balance of the populations within an ecosystem.
Comparison with Sexual Reproduction
Sexual reproduction differs from asexual reproduction in many significant ways.
Genetic Variation
Asexual Reproduction: The offspring produced are genetically identical.
Sexual Reproduction: The genetic material from two parents combines to give rise to a person with a unique gene combination, leading to genetic variability.
Evolutionary Advantages
Asexual Reproduction: It is advantageous in stable environments where the ability for rapid growth of a population is advantageous.
Sexual Reproduction: Increases genetic diversity, a precondition to adaptation and evolution in the long run.
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Recommended Video on Asexual Mode of Reproduction
Frequently Asked Questions (FAQs)
The major types of asexual reproduction in animals include binary fission, budding, fragmentation, regeneration, and parthenogenesis.
While most higher animals reproduce sexually, some are capable of asexual reproduction under certain conditions. For example, parthenogenesis occurs in some species of lizards and sharks.
Yes, plants can also reproduce asexually. One such method is vegetative propagation. It is a type of asexual reproduction found in all plants such as jasmine and roses. In this reproduction, new plants are created with the help of vegetative plant parts. Vegetative plant parts include roots, stems and buds.
This process can be natural or man-made.
Fragmentation is defined as the process of asexual reproduction. In this form of reproduction, the lost parts of the organism act and function as new organisms. Spirogyra is an algae with the ability to fragment. The Lost Spirogyra part works like one Spirogyra.
Asexual reproduction takes less time because it does not require the presence of motile gametes, male sperm and female gametes, and fusion between the two gametes. This is a time-consuming process because sexual reproduction requires the presence of male and female gametes and mating between them.