Question

Which of the following phenotypes shows up more often in human males than in human females?

1. Colorblindness

2. Huntington's Disease

3. Sickle Cell Anemia

4. Type B blood

Answer 1

Answer : 1 ; Colorblindness.

Explanation : It is more found in human males. Colorblindness is a one type of X-linked inheritance. In that case the gene responsible for colorblindness are located on the X chromosome, males have only one X chromosome whereas females have two X chromosomes. As males have only one X chromosome so if it defective then it enough close to cause colorblindness in males but in females have two X chromosomes, so in that case it requires two defective X chromosome to cause colorblindness. This type of inheritance pattern is called X-linked inheritance and it primarily affects males.