The 4 types of sex cells

Humans, like most other animals, are multicellular organisms that perpetuate our species through the type of reproduction we call sexual. This type of reproduction, which results in the emergence of individuals with genetic characteristics from two individuals, which gives the species a much greater variability than that offered by asexual reproduction.

In order for sexual reproduction to produce a new being, a certain type of cell will have to merge: sex cells or gametes. These are the ones we will talk about in this article.

    Gametes or sex cells

    They are called gametes or sex cells for a certain type of cell that its main function is to generate a new being, Perpetuate progenitor species and genes.

    The sex cells have different shapes, being concretely of two types the union will be the one that generates the zygote from which it will eventually develop a new individual. The specific name of these cells depends on the type of living things we are talking about, there is a man and a woman.

    This type of cell it has half of the chromosomes of the species in questionSomething which when the new being appears before the union or fusion of two cells from two different individuals allows the child organism to end up having the same number of chromosomes as its parents, although with information genetics different from any of the above. After their union, a genetic recombination of the genetic information from the two cells takes place, generating a unique genetic code thanks to this recombination.

    In the case of humans, we have a total of 46 chromosomes divided into 23 pairs. Of these, 22 of the pairs correspond to somatic chromosomes and are equal regardless of sex. however pair 23 differs between men and womenIt is the sex chromosomes that mark our genetic sex. Specifically, the man has one X chromosome and one I chromosome, while the woman has two X chromosomes.

      Sex cells in animals

      When we talk about sex or sex cells, the first thing we think of is the type of reproduction and the cells we have that also have the rest of the animal species: sperm and eggs.

      semen

      Sperm named in male sex cells, and who have half of the genetic information necessary to form a new living being. It is a type of cell of very small size, smaller than that of female gametes, and formed in large numbers in the testes of males of each species.

      In order for fertilization to occur, it is necessary for the sperm to move to the egg, only one of which (usually, although there are exceptions) has managed to enter the egg and combine its genetic material with him. This is why the sperm presents morphological adaptations which allow this displacement.

      Its basic morphology is as follows:

      We can first observe the existence of a large head (most of the sperm) in which we can find the nucleus, In which the genetic information in question can be found, and the acrosome or the layer formed by various enzymes that allow them to allow sperm to enter female gametes. In addition to this, we can find different substances that help nourish and allow the movement of sperm.

      The other main part is the tail or flagellum, through which sperm can move around inside the woman’s body until they reach the egg. Inside, we find first a small neck through which it joins the head, then an intermediate piece in which we can find different mitochondria, Which make it possible to produce enough energy (through the substances present both in the own sperm and in the rest of the sperm) and finally the flagellum or final part, which moves to allow the displacement.

        eggs

        Eggs are female sex cells, which carry half of the genetic information necessary for the genesis of a new being. It is a type of large cell, which has the shape of a sphere and which they are produced by the ovaries of females of different species.

        The ova have the characteristic that they are not always available for fertilization, there is a whole cycle during which an ovum is produced, matures, remains available for possible reproduction and becomes detached in the event of non-fertilization, that is is the menstrual cycle. It is generated about once a month (in fact, it’s usually 28 days).

        Also, unlike sperm present in large quantities throughout life, there are only a certain number in each female. During reproduction itself, the egg remains immobile, until the sperm reach it and finally unite manage to penetrate it (in case it is reached).

        The structure of this cell is as follows, from the inside to the outside:

        First, it highlights the nucleus in which is the genetic information that would allow the formation of a new being to bind to a sperm. We also find the Vitelio inside, A series of substances as a reservoir of energy that would allow the survival of the zygote until the formation of a placenta. All of this would be surrounded by a plasma membrane that limits the cell and through which chemical elements can enter and exit that allow its interior to be chemically balanced.

        Around the membrane you can find a gelatinous protective layer, called the pellucida layer, Which acts as a protection while allowing the entry of a first semen and eventually hardens to prevent more than one from entering. A final, outermost layer is the radiata crown. This will be particularly relevant for regulating sex hormones and generating the placenta in the event of fertilization.

        Sex cells in plants

        Semen and eggs are not the only types of sex cells that exist, being only those of animals. Plants and other plants also reproduce sexually in many cases, Being its sex cells, the oosphere and pollen.

        the oosphere

        It is called an oosphere in the female sex cell type of plants that have the ability to reproduce sexually. This type of cell can be found inside the so-called seminal rudiments located in the embryo sacs of plants, located in flowers.

        Like animal eggs, it has half as many chromosomes as other cells of its parents. The male or gamete pollen at the level of the plant comes into contact with it through the stigma of the flowers.

        The Polish guy

        Pollen is the plant equivalent of sperm: the male sex cell of plants. These are small particles in the form of grains that form in the stamens of plants. It binds to the oosphere in the process known as pollination (For this they need wind or the help of animals.

        These grains, the content of which is half of the genetic information necessary to produce a new being, come under stigma and bind to the oosphere. To do this, once in the stigma, the pollen generates a small extension called the pollen tube in order to transport its genetic material to the oosphere.

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