genetics - fd.valenciacollege.edufd.valenciacollege.edu/file/sclark/genetics (14-18).pdfgenetics...
TRANSCRIPT
genetics(chapters 14 - 18)
genetics terminology . . .
allele - alternative form of a gene
dominant allele - always expresses itself
recessive allele - only expresses itself in the absenceof a dominant allele; only expresses when alone
homozygous - identical alleles for a given trait
heteozygous - different alleles for a given trait
genotype - actual allelic composition for a trait
phenotype - physical expression of genotypes
allele - alternative form of a gene
dominant allele - always expresses itself
recessive allele - only expresses itself in the absenceof a dominant allele; only expresses when alone
homozygous - identical alleles for a given trait
heteozygous - different alleles for a given trait
genotype - actual allelic composition for a trait
phenotype - physical expression of genotypes
genetics terminology . . .
monohybrid cross results . . .
phenotypic ratio
3:1
genotypic ratio
1:2:1
between two heterozygotes
testcross phenotypic ratio
1:1
dihybrid cross results . . .
phenotypic ratio
9:3:3:1
genotypic ratio
N/A
between two heterozygotes (for both traits)
testcross phenotypic ratio
1:1:1:1
IA & IB
arecodominate
multiple alleles . . .
establishing paternity using blood test . . .
IA ____ x
IAIB
is this possible?
IA ____
♀type A
♂type A
type AB
incomplete dominance . . .
polygenic inheritance . . .
epistasis . . .
pleiotropic . . .
environmental effects . .
sex determination . . .
X-linked characteristics . . .colorblindness; hemophilia
XcY
XY
XX
XcX
XcXc
normal male
colorblind male
normal female
normal female; carrier
colorblind female
sex influenced genetic traits . . .male pattern baldness
genotype ♀ phenotype♂ phenotype
BB
Bb
bb
chromosomal mutations . . .structure
e.g. translocation . . .
chromosomal mutations . . .number
aneuploidy (2n + 1; 2n - 1)
polyploidy (3n; 4n)
excess or deficiency of one chromosome
diploid sperm and/or ovum
sex chromosome aneuploides . . .
XXY
XY XX
XYY double Y
normal male
Kleinfelter’s
normal female
Turner’s
metafemale
X
XXX
polyploidy . . .
chromosomal nondisjunction . . .
DNA research . . .
Feulgen (early 1900s)
Griffithdeveloped nucleic acid stain
bacterial transformation
Miescher (1869)
Chargaff
Wilkins & Franklin
witnessed nuclear contents
[A] = [T]; [G] = [C]
X-ray diffraction
Watson & Crickcompiled all previous data into model
Griffith . . .
Feulgen (early 1900s)
Griffithdeveloped nucleic acid stain
bacterial transformation
Miescher (1869)
Chargaff
Wilkins & Franklin
witnessed nuclear contents
[A] = [T]; [G] = [C]
X-ray diffraction
Watson & Crickcompiled all previous data into model
DNA research . . .
Chargaff . . .
Feulgen (early 1900s)
Griffithdeveloped nucleic acid stain
bacterial transformation
Miescher (1869)
Chargaff
Wilkins & Franklin
witnessed nuclear contents
[A] = [T]; [G] = [C]
X-ray diffraction
Watson & Crickcompiled all previous data into model
DNA research . . .
Wilkins & Franklin . . .
1.0 nm 0.34 nm 3.4 nm
Feulgen (early 1900s)
Griffithdeveloped nucleic acid stain
bacterial transformation
Miescher (1869)
Chargaff
Wilkins & Franklin
witnessed nuclear contents
[A] = [T]; [G] = [C]
X-ray diffraction
Watson & Crickcompiled all previous data into model
DNA research . . .
DNA replication . . .
DNA replication & Okazaki fragments . . .
gene to protein . . .transcription & translation
transcription . . .
chromosomal puffs . . .
mRNA processing . . .
transcription to translation . . .
the genetic code . . .
tRNA . . .
translation . . .
initiation of translation . . .
elongation . . .
termination of translation . . .
transcription & translation recap. . .
polyribosomes . . .
point & frameshift mutations . . .
e.g. point mutation . . .
lac operon . . .