Reproduction: Definition, Examples, Types, Importance, Types Of Reproduction

Reproduction is the process by which organisms produce their offspring. It makes sure for the survival of their species. This process involves the transfer of genetic material. The Two modes of reproduction are asexual, which involves one parent and sexual reproduction, involving two parents.

This topic is covered in the Class 12 chapter of Reproduction in Biology. The NEET biology reproduction chapter involves two modes of reproduction, i.e., Asexual and Sexual modes of Reproduction, Reproduction in Plants and Animals. Questions on human reproduction, plant reproduction, and human reproductive health are often asked in exams like NEET, AIIMS, Nursing, and Paramedical.

This Story also Contains

1. What is Reproduction?
2. Asexual Mode of Reproduction
3. Methods of Asexual Reproduction in Animals
4. Asexual Reproduction In Plants
5. Sexual Mode of Reproduction
6. Sexual Reproduction in Animals
7. Sexual Reproduction in Plants
8. Recommended Video on Reproduction

What is Reproduction?

Reproduction can be explained as a fundamental biological process by which living organisms reproduce offspring for its continuation of their respective species. This can happen through various mechanisms, either in the form of reproduction by an independent single organism or with the combination of genetic material from two organisms.

It is through this process that the survival of the species is guaranteed by way of assurance of genetic variation, adaptability to changing environments, and persistence of the life forms over generations. Reproduction is a necessity if a species is to survive, and similarly, biodiversity cannot be sustained in its absence.

There are two types of reproduction: sexual and asexual. Sexual reproduction requires the fertilization of gametes from two parents and is characterized by genetically diverse offspring. Asexual reproduction, on the other hand, involves a single organism reproducing itself with no gametes being produced; hence, the offspring are genetically identical to the parent.

Also Read:

• Practice MCQ on Reproduction

• Reproduction in Organisms

• Difference Between Sexual and Asexual Reproduction

Asexual Mode of Reproduction

A method of reproduction that involves a single organism and gives rise to offspring with a replica of the parent's genetic material.

• Only one organism is needed to reproduce; there are no gametes involved in the process.

• The offspring is an exact genetic replica of the parent and identical; variation does not exist.

• Asexual reproduction is quick, and hence, there is rapid growth in the population.

Methods of Asexual Reproduction in Animals

Asexual reproduction in animals occurs in various forms within the animal kingdom. The methods of asexual reproduction are:

Binary Fission

• In Binary Fission, the parent cell divides and gives rise to two identical daughter cells.

• Examples: Bacteria, amoeba.

Budding

• In budding, a new organism develops from an outgrowth or bud on the parent.

• Examples: Yeast, hydra.

Fragmentation

• The parent organism breaks into fragments, each capable of growing into a new organism by the process of fragmentation.

• Examples: Starfish, planaria.

Spore Formation

• The parent produces spores that can develop into new individuals.

• Examples: Fungi, algae.

Vegetative Propagation

The process of vegetative propagation is as follows:

• Natural methods: New plants grow from parts of the parent plant, such as runners in strawberries.

• Artificial methods: Methods such as cuttings, grafting, layering, and tissue culture.

Asexual Reproduction In Plants

Asexual reproduction in plants occurs through different methods. It is mainly categorised into vegetative propagation, apomixis, and sporulation. Some of the major benefits are discussed below:

Advantages and Disadvantages of Asexual Reproduction

• Enables species to colonise environments quickly.

• Useful in areas where mates are in short supply.

• Offspring are identical clones, thus uniform.

• Lack of variation makes populations more susceptible to diseases or changing conditions.

Sexual Mode of Reproduction

Sexual Reproduction is the process by which genetic material from two parents combines, resulting in genetically varied offspring.

• Typically, a male and a female are required to produce offspring.

• In fertilization, male and female gametes combine to form a zygote.

• The resulting offspring contains a combination of genetic material from the two parents. This gives rise to variation.

Sexual Reproduction in Animals

Sexual reproduction in animals is the process by which animals produce offspring involving two parents. It includes the formation and fusion of male and female gametes, leading to the development of a new organism. The sexual reproduction process includes:

Pre-fertilisation Events: Gamete Formation (Meiosis)

• Cell division in which the number of chromosomes is halved, ending with four haploid cells.

Fertilisation

• Internal fertilisation: It occurs inside the body of the female. Common in mammals and birds.

• External fertilisation: It occurs outside the body. Common in fish and amphibians.

Post-fertilisation Events

• Zygote Formation: After the sperm and egg fuse, a zygote is formed.

• Embryo Development: The zygote starts dividing and growing into an embryo.

• Growth into a New Organism: The embryo keeps developing into a baby, which is later born (in mammals) or hatches from an egg (in birds, reptiles, etc.).

Types of Sexual Reproduction

Sexual reproduction can occur in different forms depending on the type of gametes involved. These types help us understand how various organisms reproduce and pass on their traits to the next generation. The types of sexual reproduction are:

Isogamy

• It is the fusion of morphologically similar gametes.

• Examples: Some algae and fungi.

Anisogamy

• It is the fusion of gametes that differ in size or form.

• Examples: Most animals and plants.

Oogamy

• It is a form of anisogamy where one gamete, the egg, is large and non-motile, and the other gamete, the sperm, is small and motile.

• Examples: Humans, many animals, and plants.

Sexual Reproduction in Plants

Fertilisation in plants is a biological process in which a male and a female gamete combine to form a genetically variable offspring. Such reproduction is necessary for maintaining genetic diversity within populations of plants and thus adjusting to changes in the environment. The process of sexual reproduction in plants is described below:

Pollination: It is the transfer of pollen from the anther to the stigma.

• Types: Self-pollination, Cross-pollination

• Mechanisms: Wind, water, animals

Fertilisation: The fusion of male and female gametes forms the zygote.

Post-fertilization Events: Seed and fruit formation occur when ovules develop into seeds, and ovaries form fruits after fertilization.

Advantages and Disadvantages of Sexual Reproduction

• Advantage: Genetic diversity and adaptability to changing environments.

• Disadvantage: Requires more energy, slower reproduction rate.

Also Read:

Recommended Video on Reproduction