However, they should not be used interchangeably as they have hugely different meanings. The difference between gamete and zygote lies in the number of chromosomal sets within their nucleus.
The gametes are products of gametogenesis , which incorporates the process of meiosis. In particular, the sperm cells are produced by male gametogenesis called spermatogenesis whereas the egg cells are produced by female gametogenesis called oogenesis.
Both of these processes produce haploid sex cells. By haploid, it means the cell would have half of the usual set of chromosomes of a typical non-sex cell of the organism. For example, in humans, the gametes have 23 chromosomes whereas non-sex cells somatic cells have It should be noted though that the latter stage of oogenesis in humans occurs during fertilization. Thus, the female gamete will not fully complete oogenesis and it will not attain maturity in the absence of fertilization.
Instead, it disintegrates and is released during menstruation. Gametes are produced by gametogenesis; the zygote is produced by the fusion of the male and female gametes. The successful entry of a sperm cell inside the egg cell leads to a series of events, particularly plasmogamy i.
Thus, the result is a cell with twice the number of chromosomes. This condition is called diploidy. Gametes are essentially haploid for reproductive purposes. The chromosomal set of the gametes has to be reduced to half so that when the gametes combine at fertilization the integrity of the chromosomal set can be maintained across generations.
In some plants, the zygote can consist of more than two sets of chromosomes. This condition is referred to as polyploidy. In unicellular animals, the zygote can next undergo asexual reproduction to produce offspring. What does zygote mean? How does it differ from an embryo and a fetus?
A zygote is basically a fertilized cell. Although a zygote is a product of the two cells joining together, it is a single cell with a nucleus consisting of chromosomes combined from the two parents. The zygote stage is apparently the first stage of development of a multicellular eukaryote.
In humans, the zygote stage is on Day 1 of week one post-fertilization until the cell will cleave into two new cells. In humans, the embryo stage is the first eight weeks post-fertilization. An embryo is a living form consisting of many cells as a result of a zygote that underwent a series of mitosis and will soon develop a set of tubes. When does a zygote become an embryo?
In humans, at week one post-fertilization, the cells undergo extensive and rapid growth. As they continue to divide, they eventually form a solid mass of cells, called a morula. This mass of cells is not going to be a full solid sphere but a sphere with distinct layers i. The inner cell mass will differentiate into cells that will later define an embryo. The trophoblast , in turn, will give rise to cells that will become the structures essential during the uterine wall implantation and the developmental growth of the embryo to the fetus in the uterus.
Thus, the zygote not only forms the embryo but it will also be the source of the subsequent outer fetal membranes i. Because the cells divide fast, with no time to grow, the morula tends to have the same size as the zygote. See the diagram below. From one-celled, it will soon become multicellular, as each cell will undergo mitosis. This stage is crucial because the dividing cells are more sensitive to the effects of mutagens. Once a sperm has safely docked inside an egg cell, the egg takes steps to keep other sperm out.
The egg cell, which had been suspended in the middle of meiosis, now resumes this process. Meiosis is the process that creates gametes -- sperm and egg cells -- containing only one, or a haploid, set of chromosomes. Fertilization establishes the regular diploid number of chromosomes in the zygote. Meiosis occurs over two cycles of cell division, which sperm cells complete before fertilization. Meiosis in the egg cell stops during metaphase of the second cycle.
At fertilization, meiosis II resumes and the duplicate copies of each chromosome are pulled apart. The egg retains a set, while the other is dispatched to a polar body that separates from the egg and eventually degrades. The tightly packed chromosomes in the sperm now begin to decondense and are surrounded by a temporary membrane that forms the paternal pronucleus. Enzymes from the egg cell assist in the formation of the paternal pronucleus.
Gametes are produced by mitosis not meiosis and after fertilization a diploid zygote is created. The single zygote cell never grows or divides my mitosis. It can only divide by meiosis to produce haploid cells once more, which then produce the main adult body.
In plants and some algae, there is a multicellular diploid and a multicellular haploid period of the life cycle. Most common flowering plants are diploid for the majority of their existence called the "sporophyte" phase , produce haploid "spores", which develop into small, but multinucleate haploid structures the "gametophyte" phase , which in turn produce the haploid gametes often just nuclei used in fertilization and zygote formation.
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