Given below are two statements : Statement I : Down's syndrome is caused by the absence of one of the X-chromosomes. Statement II : Turner's syndrome is caused by the presence of an additional copy of the chromosomes. In the light of the above statements, choose the correct answer from the options given below :

Step-by-step solution

Down's syndrome is an autosomal aneuploidy caused by the presence of an additional copy of chromosome number 21 (Trisomy 21 ). Therefore, Statement I is incorrect. Turner's syndrome is a sex chromosomal aneuploidy caused by the absence of one of the X-chromosomes, resulting in a karyotype of 45 with XO . Therefore, Statement II is also incorrect. Both Statement I and Statement II are incorrect. Answer: Both Statement I and Statement II are incorrect