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WHAT IS AUTOSOMAL RECESSIVE

INHERITANCE IN BIRDS?

Autosomal genes are located on non-sex chromosomes. (autosomal inheritance = free inheritance). In contrast to the sex-linked inheritance male and female have two chromosomes for the location of the genes. Both male and female can either be double-factor or single-factor. If a bird is double-factor the autosomale recessive factor is visible. If a bird is single-factor it is split for the autosomal recessive factor and the factor is not visible.
    Here are some mating examples:     R = the factor is present     r  = the factor is not present
MALE (rr)
F E M A L E
r
R
R
R
r
r
r
r
r
(Rr)
r
r
r
MALE (Rr)
F E M A L E
r
r
r
r
r
r
R
R
r
(rr)
r
R
r
MALE (Rr)
F E M A L E
r
R
R
R
r
r
R
R
r
(Rr)
r
R
r
Male: without the recessive factor Female: single-factor = split for the recessive factor Results:  50 % single-factor = split for the recessive factor (Rr) 50 % without the recessive factor (rr)
Male: single-factor = split for the recessive factor Female: without the recessive factor Results:  50 % single-factor = split for the recessive factor (rR) 50 % without the recessive factor (rr)
Male: single-factor = split for the recessive factor Female: single-factor = split for the recessive factor Results:  25 % double-factor = visible for the recessive factor (RR) 50 % single-factor = split for the recessive factor (rR/Rr) 25 % without the recessive factor (rr)
MALE (RR)
F E M A L E
R
R
R
R
R
r
R
R
r
(Rr)
r
R
R
MALE (Rr)
F E M A L E
r
R
R
R
r
R
R
R
R
(RR)
R
R
r
MALE (RR)
F E M A L E
R
R
R
R
R
R
R
R
R
(RR)
R
R
R
Male: double-factor = visible for the recessive factor Female: double-factor = visible for the recessive factor Results:  100 % double-factor = visible for the recessive factor (RR)
Male: double-factor = visible for the recessive factor Female: single-factor = split for the recessive factor Results:  50 % double-factor = visible for the recessive factor (RR) 50 % single-factor = split for the recessive factor (rR)                   
Male: single-factor = split for the recessive factor Female: double-factor = visible for the recessive factor Results:  50 % double-factor = visible for the recessive factor (RR) 50 % single-factor = split for the recessive factor (Rr)