Gamete
Developmental Biology · Genetics · Cell Biology
Say it: GAM-eet
A gamete is a haploid reproductive cell, such as a sperm or an egg, that fuses with a gamete of the opposite type at fertilization to form a zygote.
Also: gametes, sex cell, reproductive cell
Definition
What is a gamete?
Gametes are the cells that carry genes from one generation to the next in sexual reproduction. In animals the male gamete is the sperm and the female gamete is the egg, or ovum; plants make gametes too, in pollen and in ovules. Gametes are haploid, carrying one copy of each chromosome instead of the two copies found in most body cells.
Gametes are made by meiosis, a pair of divisions that halves the chromosome number and shuffles the parents' chromosomes through crossing over and independent assortment, so almost every gamete is genetically unique. When two gametes fuse at fertilization, the resulting zygote is diploid again. In humans the sperm is small and mobile, driven by a flagellum, while the egg is far larger, stocked with cytoplasm and nutrients, and does not swim. This difference in size between the two gametes is called anisogamy; some algae and fungi instead make gametes that look alike.
Mistakes in meiosis can leave a gamete with an extra or missing chromosome, which is the usual cause of conditions such as Down syndrome.
Word parts
Where does the word “gamete” come from?
- gamet-
- spouse (wife or husband)Greek gamete and gametes, from gamos (marriage)
Practice it
Where you'll meet it
Related
Terms that go with it
- MeiosisMeiosis is a two-stage cell division that turns one diploid cell into four genetically different haploid cells, the precursors of eggs and sperm.
- FertilizationFertilization is the fusion of a sperm and an egg, the male and female gametes, into a single diploid cell, the zygote, that can develop into a new organism.
- ChromosomeA chromosome is a thread-like structure of DNA and protein that carries an organism's genes; most human cells hold 46 of them in 23 pairs.
- AlleleAn allele is any of the alternative forms of a gene or DNA sequence that can occupy the same position, or locus, on a chromosome.
- Mendelian inheritanceMendelian inheritance is the pattern by which single genes pass from parents to offspring, following the laws of segregation and independent assortment.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
- NHGRI Talking Glossary: Gamete
- OpenStax Biology 2e, 43.6 Fertilization and Early Embryonic Development
- OpenStax Anatomy and Physiology 2e, 28.1 Fertilization
Last updated
Spotted a mistake? Tell us and we'll correct it.
Practice Developmental Biology
Free developmental biology quizzes, with an explanation for every answer.
See the Quizzes