Study the following and pick up the correct statements:
I. Sex linked inheritance due to dominant genes follow criss-cross inheritance.
II. Gene responsible for haemophilia-C lies in autosomes.
III. In sickle cell anaemia in the $\beta$-chain of haemoglobin, valine is replaced by glutamic acid at 6th position.
IV. Cystic fibrosis is due to mutation in the gene located in 7th chromosome.