Chapter 16 Section 1 Genes and Variation

1. Chapter 16 Section 1Genes and Variation Biology pgs. 393-396

2. Objectives _____________what a gene pool is _____________the main sources of inheritable variation in a population ___________what determines how a phenotype is expressed Explain Identify State

3. Gene Pool • A ____________is a group of individuals of the same species that interbreed. • A _____________consists of all genes, including all the different alleles, that are present in a population. population gene pool

4. Relative Frequency The ________________of an allele is the number of times the allele occurs in a gene pool, compared with the number of times other alleles for the same gene occur. relative frequency

5. Genetic Variation • In genetic terms, evolution is any ____________in the relative frequency of alleles in a population. • The two main sources of genetic variation are ____________and the genetic shuffling that results from sexual reproduction. change mutations

6. The number of ____________produced for a given trait depends on how many genes control the trait. phenotypes