To make chromosomal studies easier, chromosomes are classified into certain groups. So, the chromosome number 21,22 and Y are listed in

Step-by-step solution

To make chromosomal studies easier, chromosomes are classified into certain groups like A to G. So chromosome number 21, 22 and Y are listed in G. Group A contains 1-3 chromosomes B contains 4-5 chromosomes C contains 6-12 chromosomes and X-chromosome D contains 13-15 chromosomes E contains 16-18 chromosomes F contains 19-20 chromosomes G contains 21-22 chromosomes and Y chromosome