Asexual Reproduction In Animals: Examples, Advantages, Disadvantages

What Is Asexual Reproduction?

Animals reproduce through two types of reproduction: a sexual method and the asexual mode of reproduction but mammal reproduces only by means of a sexual mode of reproduction that involves two gametes. In the asexual mode of reproduction, the plant does not need different gametes named as male and female gametes. In this kind of method of reproduction, the plant reproduces independently without the use of male and female gamete. Asexual reproduction is not time-consuming or tedious. This type of reproduction does not lead to the variation that changes between organisms so the plants produced by the asexual reproduction are genetically similar to the parent plant. This kind of reproduction takes place in almost every plant.

Another method animals make use for the process of reproduction is the sexual mode of reproduction. In the sexual mode of reproduction, the animal requires the occurrence of two different gametes one being the male gamete and the second being the female gamete and as a second step the fusion between these two gametes. The two different gametes are produced from the sperm of the male and the ovary of the female, which is an egg cell. The testes make the sperms that serve as the male gamete and the ovary helps in the secretion of the female gamete. Now fusion occurs in the isthmus region of the female reproductive tract and leads to the formation of embryos which get implanted into the uterus of female reproductive organs. Microorganisms such as the bacteria divide and reproduce only by the means of asexual reproduction.

Definition Of Asexual Reproduction

Asexual reproduction is defined as the mode of reproduction in which male and female gametes are called sperms and eggs are not involved. This type of reproduction does not need the fusion of male and female gametes. In plants asexual reproduction takes place by means of various methods that are named budding and fragmentation; sometimes vegetative propagation is also used.

Features of Asexual Reproduction:

• 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

Differences Between Asexual And Sexual Reproduction

• Genetic Variation: Under asexual reproduction, all the individuals are identical, while in sexual reproduction, the genetic material gets mixed from the two parents, leading to variations.

• Reproduction Rate: It is normally faster with asexual reproduction and uses less energy compared to sexual reproduction.

• Adaptation and Evolution: Sexual reproduction allows for more genetic variation, hence offering a better adaptation and more evolution in the long term.

Type of Asexual Reproduction

Asexual reproduction occurs in various forms within the animal kingdom. The significant ones include:

Binary Fission

It is defined as the 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. Her two divisions exist here. One is the nuclear division called karyokinesis and the other is the cytoplasmic division called karyokinesis called cytokinesis.

• Longitudinal Binary Fission:

When fission occurs through the longitudinal plane this type of fission is called longitudinal binary fission.

Examples include Euglena.

• Transverse Binary Fission:

When fission occurs through the transverse plane this is termed transverse binary fission.

Planaria and diatoms reproduce by this method of fission. The parent organism behaves as a new daughter cell and loses its identity.

Spore Formation

When Unfavorable 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 a 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 algae 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 it's both parts behave as individual cells.

Budding

It 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

In this 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

In this 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 asexual mode of reproduction.

Advantages And Disadvantages Of Asexual Reproduction

Advantages

• Higher Reproduction Rate: With asexual reproduction, a very large no of offspring can be produced within a very short period.

• No mate required: It does not need any mate for the reproduction process; this advantage is particularly useful where an organism is isolated.

• Energy Efficiency: Less energy is required compared to sexual reproduction as there is only one parent involved.

Disadvantages

• Lack of Genetic Variation: The offspring are genetically identical, so adaptation to changed conditions may be limited.

• Potential for Overcrowding: A quick act of reproduction can result in overcrowding and competition for the very same resources.

Ecological And Evolutionary Significance

Asexual reproduction has a huge part in the adaptation and survival of species, together with their 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 colonize 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.

Energy Investment

• Asexual Reproduction: It requires less energy investment because it involves only one parent.

• Sexual Reproduction: More investment in energy because two parents are required, and searching for a mate.

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.