Human Genetic Traits
description
Transcript of Human Genetic Traits
![Page 1: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/1.jpg)
![Page 2: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/2.jpg)
Importance of geneticsImportance of genetics• Understanding hereditary diseases and to Understanding hereditary diseases and to
develop new treatmentsdevelop new treatments• Organ donor matchesOrgan donor matches• PaternityPaternity• ForensicsForensics• EvolutionEvolution
![Page 3: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/3.jpg)
Genes- genetic material on a chromosome that codes for a specific traitGenotype- the genetic makeup of the organism for a trait
Phenotype- the physically expressed trait (what you look like)
Allele- alternative forms of a gene (comes in dominant & recessive)
![Page 4: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/4.jpg)
Gregor Mendel’s Law of Complete Dominance
• Two alleles are carried for each trait• In true-breeding individuals, both
alleles are the same (homozygous).• Hybrids, on the other hand, have one
of each kind of allele (heterozygous).• The dominant allele form covers the
recessive allele form
![Page 5: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/5.jpg)
Genetic InformationGenes produce proteins
Proteins (brown eye pigment, hair shape)
Trait (how you look; phenotype)
![Page 6: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/6.jpg)
Homologous Chromosomes-pair of chromosomes that contain the same genes (one from mom/one dad)
QuickTime™ and a decompressor
are needed to see this picture.
![Page 7: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/7.jpg)
Allele ExampleGene = “eye color”
Alleles (gene forms possible)
brownbluegreenlavender
![Page 8: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/8.jpg)
Allele Examples
appearance
eye color:Homozygous (both alleles same)
![Page 9: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/9.jpg)
Allele Examples
appearance
eye color:Heterozygous (Bb),Two different alleles (brown dominant over blue)
![Page 10: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/10.jpg)
Genotype vs Phenotype
homozygous(dominant)
heterozygous
homozygous(recessive)
genotype phenotype
QuickTime™ and a decompressorare needed to see this picture.
QuickTime™ and a decompressorare needed to see this picture.
QuickTime™ and a decompressorare needed to see this picture.
![Page 11: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/11.jpg)
STOP HERE
![Page 12: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/12.jpg)
Punnett SquareIf male & female are heterozygous for eye color
X
brown: 3/4 offspringblue: 1/4 offspring
male
female
![Page 13: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/13.jpg)
PKUEach parent carries one gene for PKU.
P p
P pX
P
p
pP
PP
Pp
pP
pp
Possible genotypes: 1PP 2Pp 1pp
Possible phenotypes:no PKU PKU
![Page 14: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/14.jpg)
Compare this to what would have happened if one parent was homozygous for sickle cell.
HbA HbA
HbS HbSX
HbS
HbS
HbAHbA
HbA
HbS
HbA
HbS
HbS
HbA
HbS
HbA
all offspring are carriers of sickle cell trait
![Page 15: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/15.jpg)
Autosomes and Sex Chromosomes
![Page 16: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/16.jpg)
Red-Green Color BlindnessSex-linked trait
XC Y
XC Xc
X
XC
Xc
YXC
XC
XC
XC
Y
Xc
XC
Y
Xc
Normal male
Normal female recessive gene
Possible outcomes: XCXC XCXc XCY XcYNormal female
Normal Female(carrier)
Normal male
Color-blind male
![Page 17: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/17.jpg)
Dominance
Most traits show complete dominance
Blending unexpected
![Page 18: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/18.jpg)
E unconnected earlobee connected earlobe
allele gene
P EE x ee
gametes E e
F1 Ee
unconnected
connected
![Page 19: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/19.jpg)
F1 Ee x Ee
gametes1/2 E 1/2 e1/2 E 1/2 e
E
e
E e
EE Ee
Ee ee
F2 1 EE 2 Ee 1 ee
PunnettSquare
![Page 20: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/20.jpg)
P
F1
F2
EE, ee
Ee
EE, 2 Ee, ee
50%
100%
75%
1:1
1:1
1:1
generation genotypes unconnected E:e
Basis of the Castle-Hardy-Weinberg Law
phenotypes
ratio of alleles in the population
![Page 21: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/21.jpg)
Genotypes Phenotypes
Experiment to determinedominant vs. recessive
![Page 22: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/22.jpg)
Genetic Sleuthing
My eye color phenotype is brown.
What is my genotype?
![Page 23: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/23.jpg)
Pedigree phenotypes
infer genotypes
Alternative:look directly at the DNA
![Page 24: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/24.jpg)
Complexities
Multiple genes for one trait
Example: eye color
Blended traits (“incomplete dominance”)
Influence of the environment
![Page 25: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/25.jpg)
Disorders
Down’s Syndrome (chrom 21)
Huntington’s (chrom 4)
Alzheimer’s (chrom 1, 10, 14, 19, 21)
![Page 26: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/26.jpg)
![Page 27: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/27.jpg)
Tongue RollerTongue Roller
R = Tongue Rollerr = Unable to Roll Tongue
![Page 28: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/28.jpg)
Widow’s PeakWidow’s Peak
W = Widows Peakw = Lack of Widow’s Peak
![Page 29: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/29.jpg)
Free Ear LobeFree Ear Lobe Attached Ear Lobe
E = Free Ear Lobee = Attached Ear Lobe
![Page 30: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/30.jpg)
Hitchhiker’s ThumbHitchhiker’s Thumb
Hi = Straight Thumbhi = Hitchhiker’s Thumb
![Page 31: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/31.jpg)
Bent Little FingerBent Little Finger
Bf = Bent Little Fingerbf = Straight Little Finger
![Page 32: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/32.jpg)
Mid-digital HairMid-digital Hair
M = Mid-Digital Hairm = Absence of Mid-Digital Hair
![Page 33: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/33.jpg)
DimplesDimples
D = Dimplesd = Absence of Dimples
![Page 34: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/34.jpg)
Short HalluxShort Hallux
Ha = Short Halluxha = Long Hallux
![Page 35: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/35.jpg)
Short Index FingerShort Index Finger
Ss = Short Index FingerS1 = Long Index Finger
*Sex-Influenced Trait*Sex-Influenced Trait
![Page 36: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/36.jpg)
Presentation created by J. Kenyon
Pttttthhhhhhhtttt!
Kiss me, you fool.
![Page 37: Human Genetic Traits](https://reader035.fdocuments.us/reader035/viewer/2022062810/56815d4a550346895dcb52c6/html5/thumbnails/37.jpg)
Genetic Testing
Would you want to know?
• Ethical concerns• Cost• Insurance companies
see GATTACA