Why is human genome project called a mega project ?

In history of biology, human genome project led to development of :

What is human genome project? Write down four goals of human genome project.

What is Human genome project ? Briefly write about the salient features of Human Genome project.

Why is human heart called autorhythmic heart?

What is Human Genome Project? Discuss the application and future challenges of Human Genome Project.

What do 'Y' and 'B' stand for in 'YAC' and 'BAC' used in Human Genome Project (HGP). Mention their role in project.