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  2. Meiosis - Wikipedia

    en.wikipedia.org/wiki/Meiosis

    Meiosis produces haploid gametes (ova or sperm) that contain one set of 23 chromosomes. When two gametes (an egg and a sperm) fuse, the resulting zygote is once again diploid, with the mother and father each contributing 23 chromosomes. This same pattern, but not the same number of chromosomes, occurs in all organisms that utilize meiosis.

  3. Origin and function of meiosis - Wikipedia

    en.wikipedia.org/wiki/Origin_and_function_of_meiosis

    Meiosis generates genetic variation in the diploid cell, in part by the exchange of genetic information between the pairs of chromosomes after they align (recombination). Thus, on this view, [28] an advantage of meiosis is that it facilitates the generation of genomic diversity among progeny, allowing adaptation to adverse changes in the ...

  4. Human fertilization - Wikipedia

    en.wikipedia.org/wiki/Human_fertilization

    The sperm plasma then fuses with the egg's plasma membrane and their nuclei fuse, triggering the sperm head to disconnect from its flagellum as the egg travels down the fallopian tube to reach the uterus. In vitro fertilization (IVF) is a process by which egg cells are fertilized by sperm outside the womb, in vitro.

  5. 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 . [1]

  6. Reproduction - Wikipedia

    en.wikipedia.org/wiki/Reproduction

    Sexual reproduction typically requires the sexual interaction of two specialized reproductive cells, called gametes, which contain half the number of chromosomes of normal cells and are created by meiosis, with typically a male fertilizing a female of the same species to create a fertilized zygote. This produces offspring organisms whose ...

  7. Spermatogenesis - Wikipedia

    en.wikipedia.org/wiki/Spermatogenesis

    The spermatids are transformed into spermatozoa (sperm) by the process of spermiogenesis. These develop into mature spermatozoa, also known as sperm cells. [2] Thus, the primary spermatocyte gives rise to two cells, the secondary spermatocytes, and the two secondary spermatocytes by their subdivision produce four spermatozoa and four haploid ...

  8. Human reproductive system - Wikipedia

    en.wikipedia.org/wiki/Human_reproductive_system

    Each ovary contains hundreds of egg cells or ova (singular ovum). Approximately every 28 days, the pituitary gland releases a hormone that stimulates some of the ova to develop and grow. One ovum is released and it passes through the fallopian tube into the uterus. Hormones produced by the ovaries prepare the uterus to receive the ovum.

  9. Pronucleus - Wikipedia

    en.wikipedia.org/wiki/Pronucleus

    The purpose of the cell membrane was to protect the DNA from the acidic vaginal fluid, and the purpose of the tail of the sperm was to help move the sperm cell to the egg cell. The formation of the female egg is asymmetrical, while the formation of the male sperm is symmetrical. Typically in a female mammal, meiosis starts with one diploid cell ...