12.4 Mutations Changes in the genetic material Mistake in copying (carcinogens) *Single gene or *Entire chromosome

Gene Mutations Changes in a single gene 1. Explain what a POINT MUTATION is 2. Explain THREE types of P.M. 3. Explain what a FRAMESHIFT MUTATION IS 4. Which P.M. are frameshifts?

Chromosomal Mutations -Changes in the no. or structure of chromosomes 5. Explain what a chromosomal mutation is. 6. What are the four types of chromosomal mutations?

7. Explain three possible consequences of mutations. 8. Describe a polyploid plant. What would it look like? Describe its genetic makeup.

Point Mutations Changes in 1 or a few nucleotides Substitutions – affect no more than a single amino acid

Insertions and deletions Frameshift Mutations Insertions and deletions They shift the reading frame of the genetic message… remember bases are read in groups of three Entire protein can be ruined

Chromosomal Mutations Changes in the number or structure of chromosomes Can change locations of genes on chromosomes or number of copies of some genes

Chromosomal Mutations

Are mutations harmful? Most have little to no effect on gene expression or protein function Some harmful…genetic disorders Source of genetic variability in species Polyploidy – set of chromosomes does not separate (nondisjunction)

12.5 Gene Regulation Expressed gene is one that is transcribed into RNA Regulatory site is where other proteins binding to the DNA can regulate transcription Promoter is the RNA polymerase binding site Operon is a group of genes that operate together

Eukaryotic Gene Expression

Differentiation Cells become specialized in structure and function Hox genes-control differentiation of cells and tissues in the embryo