How does a gametophyte produce gametes? How does a spore grow into a gametophye? What is the purpose in a spore being able to travel far distances? I am going to answer your questions somewhat out of order because I think things will make a bit more sense that way.
A spore is a haploid cell produced by meiosis. Being able to disperse long distances, and be viable over long time frames, allows spores to colonize new habitats that may be terrific to grow in, but far from the parent plant. It also allows them to be able to wait a long time for favorable growing conditions to occur.
Both really important traits for plants. Once the spore lands in a good spot, it grown in the haploid gametophyte. Since the gametophyte is already haploid, it does not need to change the number of chromosomes to produce a gamete and so the haploid gametophyte produces haploid gametes by mitosis. Let me know if you have more questions or would like more clarification on any of this life cycle.
I see now! Is this correct: Once the male gametophyte is grown, then it will depend on external factors to disperse the pollen wind, insects etc. In Gymnosperms and Angiosperms, the male gametophyte and the pollen grain are two names for the same thing.
And yes, for the pollen grain to get to the egg or near enough to fertilize it , it relies on external factors wind, water, insects, birds, bats, etc. And you are also correct that once fertilization occurs, the sporophyte will grow. Let me know if there are other subjects that you would like a piece written on, and I will see what I can do. All Phyla of plants use both spores and gametes. Having a multicellular gametophyte generation AND a multicellular sporophyte generation is one of the defining traits of plants.
This was a great explanation but I would like to know what is the point for a plant to have both spores and gametes… Thank you! Each type of cell has pros and cons. Most plant gametes are fragile and do not remain viable for long; however, they are the mechanism for sexual recombination and so provide an important benefit for species adaptability and survival. Spores are very tough and can survive for long periods of time and through a wide range of very harsh conditions and so are very good for dispersal; however, they simply produce a clone of the sporophyte and so do not contribute much to adaptability.
By having both gametes and spores in their life cycles, plants benefit from the abilities to both disperse over large areas to find new regions to colonize, and also have the genetic flexibility to adapt to new conditions when they arise. Why gamete becomes sporophyte and spore becomes gametophyte Sound Amazing….
The single-celled structures are named according to what produces them. So a gametophyte, the multicellular 1n body, produces the gamete. The sporophyte, the multicellular 2n body, produces the spore. Hi Sadiq, I am glad this information was useful! Let me know if there are other topics that you would like information on. You are very welcome.
Let me know if there are other topics you would like discussed. I am happy to look into different topics and write about them if I can. Gametes are mature haploid cells which are able to unite with another mature haploid cell in sexual reproduction to form a zygote. The gametophyte stage of the plant life cycle has a haploid body. So to produce haploid gametes, the haploid gametophyte causes some cells to divide. No change in chromosome number is needed. A cell division with no change in chromosome number is a process called mitosis.
Does that address your question? Take single spore cell, whether a single-celled spore on its own dispersing thousands of miles, or part of a multi-cellular gametophyte, how is it different from a gamete? They are both haploid after all. Why can the spore not just be a gamete and join with another and be diploid? What happens in gametophyte when one of its cell turns into a gamete, or when a spore cell divides and becomes two gametes?
At a fundamental level, what has changed that now makes a gamete and allows it to fertilize or be fertilized by another? The growth of a gametophyte and the generation of a gamete are both by mitosis, so what changes?
Name three advantages of seeds over spores in terms of their ability to disperse. Compared to spores , seeds can store more resources, slow down their metabolism, and exhibit dormancy, all of which aid their dispersal. What is the name and function of the structure in each whorl of a flower? All flowering plants produce seeds. The seeds are a tiny part of a plant which gives rise to a new plant. Different seed is found in different shapes, sizes, and colors.
Not all plants produce seeds as a means of reproduction. Non-flowering plants, such as ferns, reproduce through the use of spores. While both seeds and spores produce the next generation, seeds are a more developed way of reproduction that offers many advantages. Ferns, Liverwarts, Mosses, Gymnosperms, and Horsetail. Fungi are not Plants but they also have spore. Here are some examples for you regarding spore bearing plants fungi.
Angiosperms are the flowering plants. Their seeds develop inside a female reproductive part of the flower, called the ovary, which usually ripens into a protective FRUIT. Gymnosperms conifers, Ginkgo, and cycads do not have flowers or ovaries.
Their seeds mature inside cones. Plants disperse their seeds in lots of different ways. Some seeds are transported by the wind and are shaped to float, glide or spin through the air. Some seed pods are designed to explode and throw the seeds a good distance from the parent plant.
Many plants also use animals to carry their seeds. Spores are one adaptation that made it possible for plants to reproduce on land. A is a young plant that is enclosed in a protective coating. Within the coating are enough nutrients to enable the plant to grow.
Seeds and spores can both withstand harsh conditions. Gymnosperm seeds are often configured as cones. The endosperm is a tissue produced inside the seeds of most of the flowering plants following fertilization. It is triploid in most species. It surrounds the embryo and provides nutrition in the form of starch, though it can also contain oils and protein. In meiosis, however, you start with a diploid cell that divides twice to produce four haploid cells.
They are produced in the meiosis of the sporangium of diploid sporophyte. Spores are produced by bacteria, algae, protozoa, fungi and plants. One of the most characteristic features in spores is that they are adapted to dispersal and survival in unfavorable conditions.
But under favorable conditions, spores develop into new organisms. They produce multicellular gametophytes by mitotic cell division which eventually produce gametes.
Bacteria produce spores as resistant units in order to survive under unfavorable conditions. Thus, bacterial spores are not sexually reproductive units. The spores of the seed plants are produced internally. The spores producing vascular plants can be divided into two groups: homosporous and heterosporous. Homosporous plants produce spores of same size and type. Heterosporous plants, usually seed plants, spikemosses, quillworts and aquatic ferns, produce spores in two different sizes.
Spores can be classified by their origin during the life cycle as meiospores and mitospores. Meiospores are haploid and are produced by meiosis. They are produced in the gametophytes of angiosperms or gymnosperms. Meiospores consist of megaspores and microspores. Mitospores can be either haploid or diploid. Fungi is also classified into several taxa depending on the spore producing structure.
Spores can also be classified by mobility and function. Fungal spores are shown in figure 1. Gametes are haploid reproductive cells, containing a half of the genetic material needed to form an individual of a particular species. Gametes are produced during meiosis. They need to be fused with reproductive gametes of the other type in the same species in order to form a complete organism. Gametes can be divided into two groips depending on the morphology: anisogamy and isogamy. Morphologically two distinct types of gametes can be identified in anisogamy : female gamete which is comparatively larger and male gamete which is smaller.
Female gamete is called ovum whereas the male gamete is called as the sperm. In humans, ovum is , times larger than the sperm in volume. Human gametes are shown in figure 2.
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