Biology Honors I! ! Name ___________________ Period ___ Worksheet 13.3: Mutations (pages 372-376; iBooks pages 630-637) 1. What are mutations? ______________________________________ ! _____________________________________________________ 2. __________ True or False: Chromosomal mutations result from changes in a single gene 3. Mutations that occur at a single point in the DNA sequence are called ! _________________________________________. 4. A mutation involving the insertion or deletion of a nucleotide is a(n) ______________ mutation. 5. Fill in the concept map. Point Mutations Substitution 6. Use the words in the box to add headings to the three lower parts of the diagram. insertion deletion substitution 1 Biology Honors I! ! Name ___________________ Period ___ Complete the following sentences by using the terms in the box found in the previous question. 7. In a(n) _________________________, one base is changed to a different base. 8. In a(n) _________________________, a base is inserted into the DNA sequence. 9. In a(n) _________________________, one base is removed from the DNA sequence. 10. Which of the following can result in a frameshift mutation? Circle each correct answer. A. deletion B. substitution C. insertion 11. Why is a frameshift mutation more damaging than a substitution? ! ________________________________________________________________ ! ________________________________________________________________ 12. Write the name of the chromosomal mutation underneath each chromosome in the left column. ! Original Chromosome!! AB C ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! _____________________ ! ! ! ! ! JK LDE F _____________________ A B B C ! CB F _____________________ ABC DE F ! DE F AE D DE F AB C ! ! Mutation A C DE F AB C ! ! DE F AB C ! ! DE F _____________________ 2 Biology Honors I! ! Name ___________________ Period ___ 13. Use the above diagram to help you fill in the table. Chromosomal Mutation Description Part of the chromosome is lost. Extra copies of a part of a chromosome are made. Part of a chromosome breaks off and attaches to another chromosome. Sections of a chromosome are reversed. 14. Which types of chromosomal mutations can add genes to a chromosome? ! ! _________________________ 15. Which type of chromosomal mutation can take genes away from a chromosome? ! ! _________________________ 16. Which type of chromosomal mutation changes the order of the genes, but not the number of genes in a chromosome? ! ! ! ! ! ! ! _______________________________ 17. What is polyploidy? __________________________________________________ ! ________________________________________________________________ 18. Using your notes, explain how a silent mutation occurs. ! ________________________________________________________________ ! ________________________________________________________________ ! ________________________________________________________________ ! ________________________________________________________________ 3