Question

this karyotype has an extra chromosome on the 13th pair, indicating pataus syndrome. which genetic abnormality does this represent? 13 14 15 16 17 18 19 trisomy 18 monosomy 23 monosomy 21 trisomy 13

Explanation:

Trisomy means having three copies of a chromosome instead of two. Monosomy means having only one copy. Since there is an extra chromosome (three in total) on the 13th pair, it is trisomy 13. Trisomy 18 would be three chromosomes on pair 18. Monosomy 23 and 21 are having only one chromosome on pair 23 or 21 respectively, which is not the case here as there is an extra (not a missing) chromosome on pair 13.

Answer:

trisomy 13