What object has the same object as a dna molecule

Why has two different alleles for the same trait?

Color blindedness is a sex-linked trait. if we could see the pedigree chart for several more generations of the family illustrated here, we would expect a) more males to be color blind. eliminate b) more females to be color blind. c) no females to ever be color blind. d) an equal number of males and females that are color blind.

Adistinctive characteristic of mammals that is not observed in other vertebrates is