Expressed sequence tags (ESTs) is an approach practiced in _____.

Statement (S): Less than $2\%$ of the human genome encodes for functional units called 'proteins'.

Reason (R): The majority of the human genome is regulatory in nature.

Which of the following is true?

Study the following statements
I) Gene that codes for the synthesis of dystrophin is the largest human gene
II) Chromosome $21$ contains the highest number of genes
III Endonucleases are used to cut the DNA at specific region
IV) Whole hereditary information encoded in DNA of an organism is called genome

Among the above identify the correct statements