Chapter 11, Problem 19A

Summary Introduction

To evaluate:

The difficulties in performing genetic analysis in humans

Introduction:

The traditional methods used by geneticist to investigate genetics of plants, animals and microbes are not suitable to be used on humans. A pedigree is a useful tool for investigating human inheritance.

Answer to Problem 19A

Scientists are limited by time, ethics and circumstances. There are social, legal and medical implications of genetic testing. So study of human genetics is difficult.

Explanation of Solution

Pedigrees are used to infer genotypes from the observation of phenotypes. By knowing physical traits genealogists can determine which genes would be present in an individual. Phenotypes of entire families are analyzed in order to determine family genotypes.

It is very important therefore, to maintain records within the families so that disorders in future offspring can be predicted. More accurate predictions can be made if several individuals from the family are evaluated. This is very time consuming and requires several decades for each generation to mature and have offspring. There are ethical concerns also in knowing about the genetic disorders.

There are many difficulties in conducting genetic tests especially in new born babies and fetus. Scientists are limited by the circumstances under which these tests should be used, how much data must be used and for what purpose. Study of human genetics is an evolving field so there are conflicts in its research and clinical trials. There are legal issues as well.