Chapter 6.3, Problem 5TPSQ

(a)

Summary Introduction

To determine:

Whether these concordances suggest that trait X is influenced by genetic factors.

Introduction:

Comparisons of monozygotic and dizygotic twins can be used to assess the importance of environmental and genetic factors in producing differences in a particular characteristic. If both members of a twin pair have a common trait, then they are said to be concordant and if only a single member of the pair has the trait then, then the twins are said to be discordant. Concordance is the percentage possessed by twin pairs that are concordant for a particular trait.

(b)

Summary Introduction

To determine:

Whether these concordances suggest that trait X is influenced by environmental factors.

Introduction:

Comparisons of monozygotic and dizygotic twins can be used to assess the importance of environmental and genetic factors in producing differences in a particular characteristic. If both members of a twin pair have a common trait, then they are said to be concordant and if only a single member of the pair has the trait then, then the twins are said to be discordant. Concordance is the percentage possessed by twin pairs that are concordant for a particular trait.

(c)

Summary Introduction

To determine:

Whether these concordances suggest that trait X is influenced by both genetic and environmental factors.

Introduction:

Comparisons of monozygotic and dizygotic twins can be used to assess the importance of environmental and genetic factors in producing differences in a particular characteristic. If both members of a twin pair have a common trait, then they are said to be concordant and if only a single member of the pair has the trait then, then the twins are said to be discordant. Concordance is the percentage possessed by twin pairs that are concordant for a particular trait.