In autosomal recessive (AR) disorders, individuals need: A. ...

[V@ndy87]

In autosomal recessive (AR) disorders, individuals need:
 
  A. Only one mutated gene on the sex chromosomes to acquire the disease
  B. Only one mutated gene to acquire the disease
  C. Two mutated genes to acquire the disease
  D. Two mutated genes to become carriers

Question 2

When analyzing the pedigree for autosomal dominant disorders, it is common to see:
 
  A. Several generations of affected members
  B. Many consanguineous relationships
  C. More members of the maternal lineage affected than paternal
  D. More members of the paternal lineage affected than maternal

[aidanmbrowne]

Answer to Question 1

ANS: C
In autosomal recessive (AR) disorders, the offspring inherits the condition by receiving one copy of the gene mutation from each of the parents. Autosomal recessive disorders must be inherited through both parents (Nussbaum et al. 2007). Individuals who have an AR disorder have two mutated genes, one on each locus of the chromosome. Parents of an affected person are called carriers because each carries one copy of the mutation on one chromosome and a normal gene on the other chromosome. Carriers typically are not affected by the disease.

Answer to Question 2

ANS: A
Pedigrees associated with autosomal dominant (AD) disorders typically reveal multiple affected family members with the disease or syndrome. When analyzing the pedigree for AD disorders or syndromes, it is common to see a vertical pattern denoting several generations of affected members.