1. MUTATIONS
Chapter 11.3, Chapter 12

2. Mutations Mutation = change in DNA sequence
Mutations can be caused by errors in replication, transcription, translation, cell division, or external agents
Mutations in reproductive cells can affect potential offspring (ex: inheritable genetic disorders)
Mutations in body cells do not get passed onto offspring (ex: if an individual develops skin cancer)

4. Types of Mutations
Point Mutations (base substitutions)= a change in a single DNA base pair
Frameshift Mutations (addition or deletion)= a single base is added or deleted from DNA

5. If a mutation causes a change in the a. a
If a mutation causes a change in the a.a. it’s called a missense mutation
If a mutation does not change the a.a. it’s called a silent mutation
If a mutation changes the a.a. to a ‘stop’ codon it’s called a nonsense mutation.

6. Point Mutations (Base Substitutions)
THE BOY CUT HIS LIP AND ATE THE HOT DOG
Point mutation
THE BOY BUT HIS LIP AND ATE THE HOT DOG
GAC  TAC
GAC  GAG
Silent mutation is when mutation makes no amino acid change
CTT  CTG
Leucine  Leucine (No change!)
Animation Quiz 14 - Mutation by Base Substitution

7. Frameshift Mutations THE BOY CUT HIS LIP AND ATE THE HOT DOG
Insertion:
THE BOY CUT HIS SLI PAN DAT ETH EHO TDO G
Deletion:
THE BOY CUT HIS LIP ANA TET HEH OTD OG

9. Chromosomal Mutations = missing or extra pieces of chromosomes, switched pieces, extra chromosomes
occurs frequently in plants, “super sized strawberries”
Few C.M.’s get passed onto offpring because the zygote dies and doesn’t develop or the mature offspring cannot reproduce

11. Mutation of genetic material will affect the proteins produced

12. Cause & Repair Some mutations are spontaneous
Mutagen = any agent that causes DNA change (ex: chemicals, radiation)
Cells have repair mechanisms and special enzymes that can fix incorrect DNA

13. HUMAN TRAITS
Chapter 12, Section 1

14. Pedigree
Pedigree = map of inheritance of genetic traits from generation to generation

17. Karyotype Chromosomes come in pairs, inherited from parents
Karyotype = a chart of chromosome pairs, can be used to visualize chromosomal abnormalities
Humans have 23 pairs of chromosomes, 46 total chromosomes

19. Autosomes = any chromosome that isn’t a sex chromosome
Human has 22 pairs (44 chromosomes)
Sex Chromosome = genes that determine an individuals gender (X and Y)
Male= XY Female= XX
Sex chromosomes are the last pair on the karyotype
Human has 1 pair (2 chromosomes)

21. Common Chromosomal Disorders
Chromosome Abnormality
Patau Syndrome
Trisomy 13
Edwards Syndrome
Trisomy 18
Down Syndrome
Trisomy 21
Jacobs Syndrome
XYY
Turner Syndrome XO
Kleinfelter Syndrome
XXY
Triple X
XXX

22. Recessive Heredity Caused by recessive alleles
Attached earlobes, Cystic fibrosis (defective protein leads to excessive mucus production in lungs), Albinism
Individual will only display the recessive phenotype if its genotype is homozygous recessive

23. Dominant Heredity Caused by dominant allele
Freckles, Widow’s peak, Hitchhickers thumb, Huntington’s disease (brain degeneration, doesn’t appear until later in age), immunity to poison ivy
Individual will display the dominant phenotype if its genotype is heterozygous or homozygous dominant

24. When Heredity Follows Different Rules
Chapter 12, Section 2

25. Incomplete Dominance
Complete Dominance = one allele completely dominates over another
Incomplete Dominance = phenotype of a heterozygote is in between the homozygous phenotypes, appearance of a third phenotype
Do not use lower case letters, use prime instead (‘) apostrophe

27. Codominance & Multiple Alleles
Both alleles for a gene are expressed in a heterozygous individual
Neither allele is dominant or recessive
Ex: Blood type
BLOOD TYPE.ppt
Blood type also shows multiple alleles, more than 2 alleles: A, B, O
Eye color also shows multiple alleles

28. Sex Determination & Sex-linked Inheritance
Combination of sex chromosomes (X and Y) determine an individual’s gender
Males XY, X chromosome comes from mom & Y chromosome comes from dad
Females XX, both mom & dad give an X chromosome
Sex-linked Traits = traits controlled by genes on sex chromosomes

29. Red-Green colorblindness
Hemophilia (blood doesn’t clot properly)
Male Pattern Baldness
Duchenne Muscular Distrophy (muscular degeneration leading to eventual paralysis)

31. Most sex-linked traits are found on genes on the X chromosome (X-linked trait) because it is larger than the Y chromosome
X-linked traits display more in males because they only have 1 X chromosome, whereas females get 2 X chromosomes so they can be carriers of the trait but not display the phenotype

32. Polygenic Inheritance
Characteristics that are influenced by several genes