The process by which a gamete, or sex cell, divides; the resulting cells have half the number of chromosomes.
A special method of cell division, occurring in maturation of the germ cells, by means of which each daughter nucleus receives half the number of chromosomes characteristic of the somatic cells of the species.
Discovered by Edouard Van Beneden in the 1870s, meiosis is the sequence of complex cell nucleus changes resulting in the production of cells (as gametes) with half the number of chromosomes present in the original cell, and typically involving an actual reduction division in which the chromosomes without undergoing prior splitting join in pairs with homologous chromosomes (of maternal and paternal origin) and then separate so that one member of each pair enters each product cell nucleus and undergoes a second division not involving reduction. Occurs by two successive divisions (meiosis I and II) that reduce the starting number of 4n chromosomes to 1n each of four product cells. Product cells may mature to germ cells (sperm or eggs).
Process of two successive cell divisions, producing cells, egg or sperm, that contain half the number of chromosomes in somatic cells. When fertilization occurs, the nuclei of the sperm and ovum fuse and produce a zygote with the full chromosome complement.
A form of cell division that takes place in the germ cells resulting in daughter cells containing one- half the chromosomes of the mother cell. Also called reduction division.
The process of cell division which results in two pairs of haploid cells, i.e. cells with only one set of chromosomes.
Process by which the sperm and egg (ovum) divide to obtain the genetic material each will contribute to a new being if the egg is fertilized.
Type of cell division that produces daughter cells with the haploid chromosome number. It occurs during the production of mature sperm and ova; the diploid chromosome number characteristic of the species is restored at fertilization. Meiosis consists of two consecutive divisions, each divided into four phases. Also called reduction division.
Division of a sex cell whereby the nucleus has 23 chromosomes.
A type of cell division that takes place during germ cell (egg or sperm cell) formation and produces four daughter cells, each with half the number of chromosomes of the original cell. In meiosis, which occurs during the formation of gametes (mature male or female germ cells) in humans, the 46 chromosomes in the germ cell divide to make two new cells, each with 23 chromosomes that pair with corresponding chromosomes to exchange bits of genetic material. In women, X chromosomes inherited from both parents form a pair, while in men, one X chromosome inherited from the mother pairs with one Y chromosome inherited from the father. Once the genetic exchange is complete, meiosis continues. When the chromosomes of a cell duplicate in a single division to produce two new daughter cells each with the same number of chromosomes as the parent cell, the process is called mitosis.
A type of cell division that produces four daughter cells, each having half the number of chromosomes of the original cell. It occurs before the formation of sperm and ova and the normal (diploid) number of chromosomes is restored after fertilization. Meiosis also produces genetic variation in the daughter cells, brought about by the process of crossing over. Meiosis consists of two successive divisions, each divided into four stages.
Meiosis, or reduction division, is the form of cell division that only occurs in the gonads that is, the testis and the ovary giving rise to the germ cells (gametes) of the sperms and the ova.
A process of two successive cell divisions, producing cells, egg or sperm, that contain half the number of chromosomes (haploid) in somatic cells. When fertilization occurs, the nuclei of the sperm and ovum fuse and produce a zygote with the full chromosome complement (diploid).
Meiosis is a form of cell division taking place in the ovaries and testes for creating egg and sperm cells. In humans, during meiosis, a cell with 23 chromosome pairs (totaling 46) splits to produce four sperm or egg cells, each containing 23 individual chromosomes.
Initially, every chromosome is replicated, resulting in a total of 92. These duplicated chromosomes connect at a location known as the centromere. Pairs of these duplicated chromosomes align and swap genetic information. Following this, the cell undergoes two divisions, creating four offspring cells, each inheriting a single version of every chromosome.
Egg and sperm cells each contain 23 individual chromosomes, which is half the typical chromosome count found in a body cell. As a result, each parent provides half of the genetic material for their offspring. Due to the genetic exchange between chromosomes, every resulting cell possesses a distinct genetic composition.
Excessive narrowing of the eye’s pupil.
A unique cell division process that results in a reduced number of chromosomes.