Suppose polymerase chain reaction (PCR) is used to amplify a single DNA marker on human chromosome 21. Further suppose that a couple who have a child with Down syndrome (trisomy 21) is examined for this marker. The mother has marker alleles of 310 and 380 bp. Her mate has marker alleles of 290 and 340 bp.

PART 1) What PCR bands are present in their child with Down syndrome if nondisjunction occurred in maternal meiosis I?

Select all the possible PCR marker combinations.

A. 290 bp, 310 bp
B. 290 bp, 310 bp, 380 bp
C. 290 bp, 380 bp
D. 310 bp, 340 bp
E. 310 bp, 340 bp, 380 bp
F. 340 bp, 380 bp

PART 2) What PCR bands are present in their child with Down syndrome if nondisjunction occurred in maternal meiosis II?

Select all the possible PCR marker combinations.

A. 290 bp, 310 bp
B. 290 bp, 310 bp, 380 bp
C. 290 bp, 380 bp
D. 310 bp, 340 bp
E. 310 bp, 340 bp, 380 bp
F. 340 bp, 380 bp
PART 3) What PCR bands are present in their child with Down syndrome if nondisjunction occurred in paternal meiosis I?

Select all the possible PCR marker combinations.

A. 290 bp, 310 bp
B. 290 bp, 310 bp, 340 bp
C. 290 bp, 340 bp, 380 bp
D. 290 bp, 380 bp
E. 310 bp, 340 bp
F. 340 bp, 380 bp
What PCR bands are present in their child with Down syndrome if nondisjunction occurred in paternal meiosis II?

Select all the possible PCR marker combinations.

A. 290 bp, 310 bp
B. 290 bp, 310 bp, 340 bp
C. 290 bp, 340 bp, 380 bp
D. 290 bp, 380 bp
E. 310 bp, 340 bp
F. 340 bp, 380 bp