Exam 24: Genetics and Genomics

A gene typically has many alleles because

Gene expression profiling catalogues the mutations in a cell.

A person normally has two alleles of a gene because

An allele that masks the effect of another is

A human cell with 46 chromosomes is

A trait determined by more than one gene is polygenic.

In a simple dominant-recessive inheritance pattern, what percentage of the offspring would exhibit the dominant trait if one parent is heterozygous and the other is homozygous recessive?

Ultrasound and maternal serum marker tests are less informative than amniocentesis or chorionic villus sampling (CVS) in diagnosing trisomy 21 because