What is Gametophyte?
The gameto means gametes and phytate means plants. The generation of planets that form gametes is called gametophytes. Plants produce gametes with the help of their sex organs. Every plant such as bryophyte, angiosperms, gymnosperms, algae, etc. goes through this. For example, algae produce simple and non-motile gametes inside its body. Spirogyra produces gametes inside their bodies and transfers gametes to another spirogyra through conjugation.
Bryophyta has antheridia and archegonia which are sex organs to make gametes. Similarly, pteridophytes and gymnosperms also consist of archegonia which are developed in different manners. Angiosperms make gametes when pollen grain development takes place. Thus, the gametophyte generation is experienced by most of these plants.
(Image will be uploaded soon)
What is Sporophyte?
Sporo means spores and phytate means plants. The generation of plants that produce spores is called sporophytes. Algae, bryophytes, angiosperms, and gymnosperms make spores. A spore is a tiny structure that leads to a new plant after its germination. Spores can be of two types, namely mitotic spore and meiotic spore. Mitosis and meiosis are types of cell divisions that lead to the formation of these spores. Mitotic spores are asexual spores and meiotic spores are called sexual spores.
Sporophyte can make both kinds of spores; algae is a simplified organism and forms mitotic or asexual spores, similarly, Chlamydomonas also form asexual spores. Bryophytes from meiotic or sexual spores, homosporous pteridophytes form the same size of spores from spore mother cell and heterosporous pteridophytes form two different kinds of spores, namely microspore from microspore mother cell and megaspore from the megaspore mother cell. Similarly, heterosporous gymnosperms and angiosperms from their spores.
(Image will be uploaded soon)
Alternation of Generation
Alternation of generations is a life cycle that includes both haploid and diploid multicellular stages. It is divided into two parts N haploid and 2n diploid. It was discovered by Strasburger. It is the conversion of gametophyte generation into sporophyte generation and vice versa.
Diploid means two sets of chromosomes (2n), one set of chromosomes from male parents, and another set of chromosomes from female parents. On the other hand, a haploid means one set of chromosomes (n) (that carry genetic information). Multicellular contains more than one cell and unicellular is containing only one cell. In plants, the lifecycle is completed by multicellular haploid cells whereas, in humans, it is undergone through unicellular haploid cells.
(Image will be uploaded soon)
Difference between Sporophyte and Gametophyte
Below is a tabular representation highlighting some of the differences between the sporophyte and gametophyte stages of the plant life cycle.
(Image will be uploaded soon)
Summary
In the life cycle of plants, generation change is a common occurrence. As a result, the life cycle is divided into two different phases: asexual and sexual. The sporophyte generation is represented by the asexual phase, while the gametophyte generation is represented by the sexual phase. Furthermore, sporophytes are diploid, meaning they have two sets of chromosomes. Gametophytes, on the other hand, are haploid and have only one set of chromosomes. This is the most important distinction between sporophyte and gametophyte. Additionally, although the sporophyte generates haploid spores, the gametophyte produces male and female gametes. Gametophyte generation is dominant in bryophytes and algae, whereas gametophyte generation is dominating in pteridophytes, gymnosperms, and angiosperms. The distinction between sporophyte and gametophyte is thus summarised.
FAQs on Difference Between Sporophyte and Gametophyte
1. What does it mean that gametophytes are dominant?
It means that the gametophytes phase of the plant can prepare its own food and doesn’t depend upon sporophytes for any nutrient. On the other hand, sporophytes depend upon gametophytes for food and are weaker than the gametophytic phase.
2. Explain the event in the life cycle of a flowering plant.
Following events take place during the life cycle of a flowering plant.
Germination: It is the stage when a plant begins to grow or germinate from a seed where roots are formed below the soil and the leaves, stem, and roots appear above the soil.
Pollination: It is the process where the pollen grains carried by wind or insects travel to another flower.
Fertilization: When the pollen reaches the ovary of another flower, the fusion of male gametes and female gametes takes place and the process is called fertilization.
Dispersal: It is the scattering of seeds by wind or animals and where some of these seeds may emerge into a new plant.
All of these stages in the lifecycle of a flowering plant lead to the beginning of a new plant through a seed. Here, the seed sprouts from a seedling which in turn is converted into a new plant. It forms new seeds and this way the cycle continues.
3. What are the different stages in the alternation of generations?
Alternation of generations between sporophyte and gametophyte takes in the following stages:
Sporangium present in diploid sporophytes undergoes meiosis to form haploid spores.
The spore develops into a gametophyte which is haploid in nature.
The gametophyte consisting of reproductive organs undergo mitosis to form haploid gametes.
These gametes fertilize to produce a haploid zygote which matures into a mature sporophyte.
Thus, the cycle keeps repeating, and one generation after the other keeps coming, this is called alternation of generations.
