Psst

Biology

Report: Heredity and variation
Mendeleian heredity law
The first Mendel law: There is called he to this law also a Law of the uniformity of the hybrids of the first generation F 1, andsays that when there cross two varieties individuals of pure race, both homocigotos, for a certain character, all the hybrids of the first generation are equal.
The individuals of this firstsubsidiary generation F1 are heterocigóticos or hybrids, since its genes alelos take information of two pure races or homocigóticas: the domineering one, which is evident, and the recessive one, whichdoes not do it.
Mendel came to this conclusion working with a pure variety of plants of peas that were producing the yellow seeds and with a variety that was producing the green seeds. Onhaving done a crossing between these plants, it was always obtaining plants with yellow seeds.

Third Mendel law. This law knows each other like that of the heredity independent of characters, and itrefers to the case of that contemplate two different characters. Each of them is transmitted following the previous laws with independence of the presence of another character.
Experiment of Mendel.Mendel crossed plants of peas of yellow and smooth seed with plants of green and rough seed (Homocigóticas both for two characters).
The seeds obtained in this crossing were all yellow and smoothones, the first law being fulfilled this way for each of the considered characters, and revealing us also that the domineering alelos for these characters are those who determine the yellow color andthe smooth form.
The obtained plants and that constitute the F1 are dihíbridates (AaBb).
These plants of the F1 cross between themselves, bearing in mind the sperm cells that each of the plants willform. It is possible to appreciate that the alelos of the different genes are transmitted by independence some of others, since in the second subsidiary generation F2 there appear yellow and rough...