Syngamy: Definition, Meaning, Types, Difference Between, Video

Syngamy is the biological process that marks the start of sexual reproduction in organisms. It involves the fusion of sperm and the egg to form a diploid zygote. This not only initiates the development of a new individual but also makes sure that the mixing of genetic material from both parents leads to genetic diversity within a species. It is an important topic in biology.

This Story also Contains

1. What Is Syngamy?
2. Types Of Syngamy
3. Process Of Syngamy
4. Importance Of Syngamy
5. Syngamy In Various Organisms
6. Factors Affecting Syngamy
7. Recommended Video On 'Syngamy'

In this article, what syngamy truly is, types of syngamy, its process with different events, importance of syngamy, significance of syngamy in different organisms, and the factors that affect the process are explained in detail.

What Is Syngamy?

Fertilisation, otherwise known as syngamy, refers to a process of sexual reproduction wherein two gametes, the sperm and the egg cells, combine to form one zygote. Following the fusion, the development of a new individual ensues, and the combination of the genetic material from both parents occurs. Through syngamy, a continuation of the species happens in that it brings forth offspring that are genetically diverse.

The importance of syngamy rests in the fact that this process is part of any organism's life cycle. On one hand, it provides a combination of genetic material to enhance variation and adaptation, while on the other, it also serves as an inducer of the embryogeny process, which gives rise to the growth of a new individual.

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• Pollination

• Difference Between Self-Pollination and Cross-Pollination

Types Of Syngamy

Syngamy based on the similarity or difference between the fusing gametes can be classified into three main types: isogamy, heterogamy, and oogamy, where each type shows a unique adaptation observed in different organisms. Here are the three types of syngamy:

Isogamy

• Merging of gametes that are morphologically similar but may differ physiologically.

• Examples: Some species of algae and fungi.

Heterogamy

• Fusion of gametes that differ in size or form.

• Examples: Most animals and some plants have this type where the egg cells are larger in size and the corresponding sperm cells are smaller.

Oogamy

• A type of anisogamy where a large non-motile egg fuses with a small motile sperm.

• Examples: Very common in reproduction in animals, most plants, and protists.

Process Of Syngamy

Syngamy is an important part of sexual reproduction, which marks the beginning of a new organism and makes sure that the genetic material from both parents gets combined. Understanding the process explains how fertilisation leads to the formation of embryos in both plants and animals. The process of Syngamy can be understood with the help of the events given below:

Pre-fertilisation Events

• Gametogenesis: Formation of male and female gametophytes by mitotic cell division and stages of meiosis

Mechanism Of Fertilisation

• Gamete contact and recognition: Gametes recognise and attach.

• Gamete membrane fusion: Plasma membranes of the gametes fuse.

• Nuclear fusion or karyogamy: Gamete nuclei fuse to form a zygote.

Post-Fertilisation Events

• Zygote formation: The combined genetic material is then enclosed within a single cell.

• Early stages of zygote development: Cell division and differentiation mark the initiation of the zygote's development.

Importance Of Syngamy

Syngamy isn't only a process of fusion of two gametes but also a cause behind genetic continuity in living organisms. This process guarantees the transfer and recombination of genetic material from both parents, which leads to genetic uniqueness in the offspring. The process of syngamy holds importance due to the following reasons:

Genetic Diversity

• Syngamy and genetic variation: The genetic material from two parents comes together to increase the resulting genetic diversity.

• Genetic diversity and its benefit for populations: A population's survival opportunities and adaptability to changing environments rise considerably.

Evolutionary Implications

• Natural selection and adaptation based on genetic variation further the evolution. Case studies of evolutionary adaptations try to include antibiotic resistance of bacteria and colouration patterns in animals.

• Syngamy also increases the chances of survival by producing offspring with advantageous traits. These traits may enhance reproduction under a changing environment.

Syngamy In Various Organisms

From the members of the Plantae Kingdom to the Animalia Kingdom, protists to fungi, each group has its own mechanism of fertilisation that suits its habitat and structure. Syngamy in various organisms is given below:

Syngamy In Plants

• Fertilisation process in flowering plants: The structure of pollen grain transfers sperm to the ovule.

• Double fertilisation in angiosperms: One sperm fertilises the egg; another fertilises the central cell to form the endosperm.

Syngamy In Animals

• Fertilisation in different animal phyla: Ranges from external—aquatic animals to internal—terrestrial animals.

• Internal vs. external fertilisation: Internal fertilisation gives more protection, and fertilisation that happens externally mostly takes place in water.

Syngamy In Protists And Fungi

• Special mechanisms of syngamy in protists and the kingdom fungi: Pluriform, mostly with complex life cycles and specialised fertilisation techniques.

Factors Affecting Syngamy

The process of syngamy is affected by many factors, whether environmental or biological. The slightest change in these factors can lead to a bigger impact. That’s why understanding these factors becomes really important to clearly understand the whole mechanism of syngamy. Syngamy is affected by the following factors:

Environmental Factors: Temperature, pH, and other abiotic factors. Environmental factors impact fertilisation.

Biological Factors: Gamete compatibility and vitality. On this basis, the compatibility and vitality of gametes depend on the success of syngamy. Example: in flowering plants, the pollen-pistil interaction & outbreeding devices.

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Recommended Video On 'Syngamy'