In 1911 the American geneticist Thomas Hunt Morgan observed crossover in Drosophila melanogaster meiosis and provided the first genetic evidence that genes are transmitted on chromosomes.
meiosis |
This method of reproduction is found for example in conidial fungi and the red alga Polysiphonia, and involves sporogenesis without meiosis.
Hybridogenesis implies that gametes of hybrids don't contain mixed parental genomes, as normally occurs by independent chromosome segregation and crossover in meiosis (see also second Mendel's law, recombination), but intact one of them or two.
Van Beneden elucidated, together with Walther Flemming and Eduard Strasburger, the essential facts of mitosis, where, in contrast to meiosis, there is a qualitative and quantitative equality of chromosome distribution to daughter cells.
The work was the result of a study in Leipzig of the testicles of the Firebug Pyrrhocoris during which Henking noticed that one chromosome did not take part in meiosis.
Scott Hawley, "Meiosis as an "M"Thing: Twenty-Five Years of Meiotic Mutants in Drosophila", Genetics (1993)