Question

an infant has a small nose, upward slant eyes, and abnormally shaped ears. the doctor suspects that the infant has down syndrome and asks the parents to consent to genetic testing of the child. which method would be used to determine if the infant has down syndrome?

○ linkage map
○ punnett square
○ pedigree analysis
○ karyotype analysis

Explanation:

Down syndrome is a chromosomal disorder (trisomy 21). A karyotype analysis is a technique that arranges chromosomes in a standard format. It can clearly show if there is an extra chromosome (in the case of Down syndrome, an extra copy of chromosome 21). A linkage map shows the relative positions of genes on a chromosome, a Punnett square is used for predicting genetic crosses (like Mendelian genetics for traits), and a pedigree analysis is used to study the inheritance pattern of traits in families over generations. None of these other methods directly visualize the number of chromosomes like a karyotype analysis does.

Answer:

karyotype analysis