Which of the following characters is NOT sex-linked?

The term "sex-linked" refers to genes that are located on the sex chromosomes (X and Y). In humans, females have two X chromosomes (XX) while males have one X and one Y chromosome (XY). Therefore, any gene located on the X chromosome will be present in two copies in females and only one copy in males. Out of the options given, albinism is not sex-linked. It is caused by a mutation in a gene on chromosome 11 and is inherited in an autosomal recessive manner. This means that both parents must carry a copy of the mutated gene for their child to inherit the condition. On the other hand, baldness, haemophilia, and colour blindness are all sex-linked conditions. Male-pattern baldness is caused by a gene on the X chromosome, while haemophilia and colour blindness are caused by genes located on the X chromosome. As a result, these conditions are more common in males than in females and can be inherited differently depending on the sex of the parent carrying the mutated gene.