Question

If the characteristic depicted in the pedigree below is subject to complete penetrance, which of the following is true?

1. 3. 1 2 3 4 100 IV

a. The characteristic can NOT be dominant because III-4 did not pass it to any of her children.

b.The characteristic can NOT be dominant because individuals I-1 and I-2 are not affected.

Answer 1

If generation is skipped than it is recessive not dominant character

> To find desorder Recessue Dominant - . Skipping of genearon than disorder Cannot be dominant (assuming full Penetration) Generation not skipped can be dominant of can be recessive. at I gener nowe Dise I 2 3 TL Dise Generation not skipped Dominant of Recessive

Generation skipped SS Recessive not dominant Generation skipped Recessive Autosoma Recessive X linked Recessive = Mostly only males are affected > Jf female diseased xdxd father must be diseased af not & hes progeny male child will be diseased No Generation skip but also can be recessive n Dominant Autosomal dominant ! x linked Dominant If male xly is diseared his mother must be diseased & his progeny female child must be diseased
In the given question generation 2 Individual show disease but neither of his parents show disease hence generation is skipped it cannot be dominant hence option b statement is true

option b is not true because parents with dominant character affected can have cenaffected progeny affected Lets take genotype of Individual 4 of generahan & Individual 5 0 I ho

They can have progeny with genotyre. themarahan TJ Aa x Ia aa a 7 - Coanetes A Aa Aa aal aa aa Taa (aa) Unaffected 50% (Aa) affected soy. Hence option a is false as they can be dominant without passing it to their ker children