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  2. Sperm - Wikipedia

    en.wikipedia.org/wiki/Sperm

    Sperm cells cannot divide and have a limited lifespan, but after fusion with egg cells during fertilization, a new organism begins developing, starting as a totipotent zygote. The human sperm cell is haploid, so that its 23 chromosomes can join the 23 chromosomes of the female egg to form a diploid cell with 46 paired chromosomes.

  3. Spermatocyte - Wikipedia

    en.wikipedia.org/wiki/Spermatocyte

    Spermatocyte. Spermatogenesis as the cells progress from spermatogium, to primary spermatocytes, to secondary spermatocytes, to spermatids and to sperm. Spermatocytes are a type of male gametocyte in animals. They derive from immature germ cells called spermatogonia. They are found in the testis, in a structure known as the seminiferous tubules ...

  4. Spermatozoon - Wikipedia

    en.wikipedia.org/wiki/Spermatozoon

    Sperm cells that give rise to female (XX) offspring after fertilization differ in that they carry an X-chromosome, while sperm cells that give rise to male (XY) offspring carry a Y-chromosome. [ 3 ] A human sperm cell consists of a flat, disc shaped head 5.1 μm by 3.1 μm and a tail known as a flagellum 50 μm long. [ 4 ]

  5. Spermatogenesis - Wikipedia

    en.wikipedia.org/wiki/Spermatogenesis

    Spermatozoa are the mature male gametes in many sexually reproducing organisms. Thus, spermatogenesis is the male version of gametogenesis, of which the female equivalent is oogenesis. In mammals it occurs in the seminiferous tubules of the male testes in a stepwise fashion.

  6. List of organisms by chromosome count - Wikipedia

    en.wikipedia.org/wiki/List_of_organisms_by...

    The list of organisms by chromosome count describes ploidy or numbers of chromosomes in the cells of various plants, animals, protists, and other living organisms. This number, along with the visual appearance of the chromosome, is known as the karyotype, [1][2][3] and can be found by looking at the chromosomes through a microscope.

  7. Human fertilization - Wikipedia

    en.wikipedia.org/wiki/Human_fertilization

    Usually 23 chromosomes from spermatozoon and 23 chromosomes from egg cell fuse (approximately half of spermatozoons carry X chromosome and the other half Y chromosome [27]). Their membranes dissolve, leaving no barriers between the male and female chromosomes. During this dissolution, a mitotic spindle forms between them. The spindle captures ...

  8. Sexual reproduction - Wikipedia

    en.wikipedia.org/wiki/Sexual_reproduction

    Sexual reproduction is a type of reproduction that involves a complex life cycle in which a gamete (haploid reproductive cells, such as a sperm or egg cell) with a single set of chromosomes combines with another gamete to produce a zygote that develops into an organism composed of cells with two sets of chromosomes (diploid). [1]

  9. Chromosome - Wikipedia

    en.wikipedia.org/wiki/Chromosome

    The autosomes contain the rest of the genetic hereditary information. All act in the same way during cell division. Human cells have 23 pairs of chromosomes (22 pairs of autosomes and one pair of sex chromosomes), giving a total of 46 per cell. In addition to these, human cells have many hundreds of copies of the mitochondrial genome.