Types Of Blood Cells - Μελετούμε το αίμα

Μαθήμα κληρονομικότητας - Παρατηρώ τα περιστέρια

Ενα γονίδιο με τέσσερα αλληλόμορφα καθορίζει τις μορφές στο φτέρωμα των περιστεριών που παρατηρούμε γύρω μας. Παρατηρήστε τα περιστέρια και αναγνωρίστε τον "αγριο" τύπο (bar type)  όπως και  τους υπόλοιπους τύπους για την μελέτη της κληρονομικότητας. 

Pigeons can have 4 different wing patterns: bar, barless, check, or t-check.

Bar is Wing pattern is controlled by a single gene, which comes in 4 different versions, or alleles.

Bar is considered "wild type," because it was the pattern in the wild ancestor to domestic pigeons. The other patterns are due to natural genetic variations, which were selected and propagated by breeders. Barless is the rarest wing pattern, available in just a small number of breeds.

The birds pictured on the right are all colored blue, but each has a different wing pattern.

The term wild-type implies nothing about an allele's dominance. It simply refers to the allele that was most commonly found in the wild ancestor. Depending on the gene, the wild-type allele can be dominant or recessive to other alleles. In fact, 'bar', the wild-type allele for wing pattern, is dominant to 'barless' and recessive to 't-check' and 'check'.

http://learn.genetics.utah.edu/content/pigeons/pattern/