Question

During a medical investigation, an infant was found to possess an extra  chromosome-21. Describe the symptoms the child is likely to develop later in the life.          (3) 

CBSE Class XII Biology Question Paper 2017

Answer 1

Down's Syndrome, the cause of this genetic disorder is the presence of an additional copy of the chromosome 21. This disorder was first described by Langdom Down. The affected individual is short statured with small round head furrowed tounge and partialy open mouth. Palm is broad with characterstic palm crease. Physical psychomotor and mental development is retarted.