Chapter 21, Problem 21.7P

a.

Summary Introduction

To predict: The probability of the daughters to be carriers for the given X linked recessive disorder.

Introduction: Genetic disorders are caused due to abnormalities that occur in one or more genes. These abnormalities can be due to changes in number or structure of the chromosome. In some cases, the abnormal or mutant allele maybe present in sex chromosomes (usually X chromosomes). The disorders caused due to these sex chromosomes are called sex linked or X linked disorders.

b.

Summary Introduction

To determine: The probability of the daughters to be carriers for the given X linked recessive disorder.

Introduction: Sex linked dominant disorders can occur both in homozygous and heterozygous conditions while autosomal recessive disorder can occur only in homozygous condition.

c.

Summary Introduction

To determine: The probability of a son to be carrier for the given X linked recessive disorder.

Introduction: A carrier consists of a defective allele responsible for an autosomal recessive disorder while the other allele is normal.

d.

Summary Introduction

To determine: The probability of a son to be affected by the given X linked recessive disorder.

Introduction: X linked recessive disorders are common in males than females because, in females, X linked recessive disorders are expressed in homozygous condition only.