Form 4 Biology Complete Notes (Readable Full Notes)

FORM IV TOPICS 1. a) i) Define the term genetics the study of heredity(inheritance) and variation or study of mechanisms by which characteristics are passed from parents to offspring iii) List some characteristics which are inherited size height/length colour/type shape yield iii) State the importance of genetics helps to explain differences between organisms of t he same species helps to explain the transmission of characters fro m generation to generation improvement in livestock improvement in crops can be used to treat some difficult diseases b) i) Explain the meaning of the following terms Heredity the resemblance among individuals related by desce nt transmission of traits from parents to offspring Trait also called character A character of the organism e.g. type of ear, colou r of eyes, height, yield etc. Gene unit of inheritance it is the heredity factor which transmits traits fr om parents to offspring genes are located at fixed points on chromosomes each point is called a locus (loci) Allele genes can exist in a series of alternative forms at a particular locus allele refers to alternative forms of genes control ling a particular characteristic Chromosomes threadlike structures found in nuclei of all plants and animals they carry