A 42-year-old woman who is pragnant with her second child comes to the clinic to get the results of her amniocentesis. The amniocentesis chromosome analysis conftrms the offspring is 47 XV+ 21.
With regards to chromosome 21, how are his cells described?
A Diploid
B Haploid
C Pentoid
D Tetroid
Triploid
Explanation
Down’s syndrome is trisomy 21. where each cell contains three rather than two copies of chromosome 21. Mosa1c Downs also exists, where only some of the cells contain three rather than two copies of chromosome
Diploid, (Option A), is incorrect. Diploid cells contain two copies of the 09. " chromosome.
Haploid, (Option B). is incorrect Haploid cells contain one copy of the chromosome.
Pentoid, (Option C). is incorrect. Pentoid cells contain f1ve copies of the chromosome. Pentoid cells containing multiple copies of the x chromosome are rarely identified.
Tetroid, (Option D). is incorrect Tetroid cells contain four copies of the chromosome. Tetroid cells containing multiple copies of the x chromosome are also rarely identified.