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 . . .

testicular feminism . . .

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 . . .