Chapter 9, Problem 4SQ

Summary Introduction

Introduction: The genes present on the chromosomes have alleles. They define the phenotypic and genotypic traits of the person. The types of alleles include dominant and recessive condition, which are depicted by a capital letter and a small letter for, example B for a dominant allele and b for a recessive allele of a gene. The combination of both the genes after recombination defines the phenotype or the external expression of the characters of a particular person. The dominant allele of a gene expresses to form a protein, whereas the recessive allele does not express and is not involved in the phenotypic expression of the characters of a person. The recessive allele is expressed only in the homozygous recessive state, when the genes for the dominant phenotype are not present.