Characters determined by a gene located on only the X-chromosome are said to be sex-linked. Such traits show a different pattern of inheritance in males and females. For example, a recessive allele on the X-chromosome
• would be masked in a female if the corresponding allele on the other X-chromosome is dominant;
• would always be expressed in a male because the Y-chromosome does not have a corresponding(active) allele.
Thus, the female may posses a homozygous or heterozygous allelic pair for a sex-linked character, but a male will only have one allele for it.
The proposed kingdom of euglenozoa includes protists with one or two flagella emerging from an anterior pocket This flagella give them the ability to swim/moved throughout the water where they usually live
