Genetically modified mosquitoes to combat malaria

A research team at Imperial College London has developed genetically modified mosquitoes to combat malaria. By embedding an endonuclease enzyme in male mosquitoes, the X chromosome is shed during sperm production, resulting in predominantly male offspring. Tests showed that mosquito populations could be eradicated within six generations.

What is the significance of the X chromosome in the context of genetically modified mosquitoes?

In how many generations did the entire populations of mosquitoes wipe themselves out?