One reason is something called trisomy 31 which is a birth defect. Polydactyly is very uncommon but some families do pass it on as it is a dominate gene. But only about 500 cases are seen per year.
People of Asian and Caucasian decent are more likely to have radial (on the thumb side) polydactyly. Ulnar (on the little finger side) polydactylism is more common in people of African decent.
Yes having 6 fingers on your hand is a dominant trait. Most people who have this trait get the extra finger cut off after birth. There is a small group in the world where the people there have 6 fingers.
Dominant trait
True
Yes, some individuals are born with a condition known as polydactyly, where they have extra fingers or toes. There are pictures and documented cases of people with six fingers and six toes, although it is a rare occurrence.
The recessive trait phenotype disappears in a one-trait test cross in the F1 generation. This phenotype can reappear in the F2 generation.
recessive trait
DOMINANT-K-
reappears in some plants in the F2 generation
A dominant trait.
the dominant trait
Recessive trait carried by a hybrid or heterozygote.
recessive trait