Biology I

1. Biology I • Chapter 11—DNA: The Molecule of Heredity

2. 11.3 Section Objectives – page 296 Chapter 11 Section 3 Objectives: • Categorize the different kinds of mutations that can occur in DNA. • Compare the effects of different kinds of mutations on cells and organisms.

3. New Vocabulary • Mutation • Point mutation • Frameshift mutation • Chromosomal mutation • Mutagen

4. 11.3 Section Summary 6.3 – pages 296 - 301 Mutations • Any change in a DNA sequence is called a ________________ • Example… Circle the mutation! Normal blood cells GGG CTT CTT TTT Sickle cells GGG CAT CTT TTT mutation

5. Mutations can be caused by errors in… • _______________ • _______________ • _______________ DNA replication transcription Cell division

6. external Nuclear radiation • They also can be caused by _______________ agents like… • __________________________ • __________________________ • __________________________ • __________________________ • Any agent that can cause a change in DNA is called a __________________ Ultraviolet radiation chemicals High temperatures Nuclear power plant workers wear film badges that monitor their exposure to radiation mutagen

7. Be harmful • Mutations may… • ______________ • ______________ • ______________ (rare) • A mutation causes the American Wirehair cat to have crimped fur…what kind of effect will this mutation have on the cat? Have no effect Be beneficial Have no effect

8. Beneficial mutations help a species to ____________ • Mutations can affect… • _________________ • _________________ evolve Reproductive cells Somatic (Body) cells

9. Mutations in Reproductive Cells • If the sequence of nucleotides in a gene of ___________ or _______ cells is changed, a mutation may affect an _____________ • Examples… • ____________ or _________ problems • Often can result in the death of the ____________ sperm egg offspring structural functional zygote

10. Mutations in Somatic (Body) Cells • Mutations to genes in your body cells, like _____, ____________, or __________ cells, will affect that _________________ • They are _____ passed on to offspring • Examples… • A cell in your stomach may lose the ability to make digestive ____________ • A skin cell may lose its ______________ • Ultraviolet radiation may cause your skin cells to reproduce too quickly, causing ___________ skin muscle lung individual not enzymes elasticity cancer

11. DNA & Mutations Animation

12. Gene Mutations • There are two types of ________ mutations that affect the production of your _____________ • _____________________ • A change in a ___________ base pair • _____________________ • A single base is ________ or _________ gene proteins Point Mutation single Frameshift mutation added deleted

13. The effects of Point Mutations • Circle the single base pair that is changed • What is it changed to? • How does this affect the protein that is made? G to A Glycine changes to serine

14. Frameshift Mutations • If the U was not deleted, what codon would be in place of UUG? • What amino acid was replaced with leucine? UUU Phenylalanine

15. Frameshift Mutations • How many amino acids were affected by the deletion? • Deleting or __________ a base causes the entire mRNA strand to ___________ 5 adding shift

16. Which type of gene mutation seems more serious…a point or frameshift mutation? Why? Frameshift, as it affects the amino acid and the order of all those that come after it.

17. 11.3 Section Summary 6.3 – pages 296 - 301 Chromosomal Mutations structural • Chromosomal mutations result in _____________ changes to a chromosome • They usually occur during errors in __________ and ___________________ • Rarely passed on to new generations because… • The zygote usually ________ • The offspring is __________ mitosis meiosis dies sterile

18. Chromosomal Mutations • Four types • _________________________ • _________________________ • _________________________ • _________________________ Deletion Insertion Inversion Translocation

19. Deletion • When a part of a chromosome is ________ out • Which gene was deleted? left D ABCDEFGH A B C E F G H Deletion

20. 11.3 Section Summary 6.3 – pages 296 - 301 • Insertion • When part of a chromatid breaks off and attaches to its ____________ chromatid • Sister chromatids have the same _______ • Results in a _____________ of genes on one chromosome • Which genes were inserted? sister genes copy B C A B C D E F G H A B C B C D E F G H Insertion

21. 11.3 Section Summary 6.3 – pages 296 - 301 • Inversion • When part of a chromosome breaks off and reattaches ______________ • Which genes were inverted? backwards B D A D C B E F G H A B C D E F G H Inversion

22. 11.3 Section Summary 6.3 – pages 296 - 301 • Translocation • When part of one chromosome breaks off and is added to a different ____________ • Different chromosomes have ___________ genes • Which genes were translocated? chromosome different W X A B C D E F G H X A B C D E F G H W Translocation Y Z W X Y Z

23. 11.3 Section Summary 6.3 – pages 296 - 301 Repairing DNA • _____________ proofread the DNA and replace incorrect nucleotides Enzymes • The greater the exposure to a mutagen, it is more likely that a mistake will ______ be corrected • Ex: Too much sun damage, will likely cause skin cancer not

24. Objective 1 • Categorize the different kinds of mutations that can occur in DNA. Point mutation Frameshift mutation Chromosomal mutation

25. Objective 2 • Compare the effects of different kinds of mutations on cells and organisms. Somatic cell – Reproductive cell – Affects the individual Example: skin cancer Affects the offspring Examples: cystic fibrosis, death to embryo