non-mendelian inheritance

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Non-Mendelian Inheritance

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Non-Mendelian Inheritance. . AaBbCc. AaBbCc. Sperm. 1 / 8. 1 / 8. 1 / 8. 1 / 8. 1 / 8. 1 / 8. 1 / 8. 1 / 8. 1 / 8. 1 / 8. 1 / 8. 1 / 8. Eggs. 1 / 8. 1 / 8. 1 / 8. 1 / 8. Phenotypes:. 1 / 64. 6 / 64. 15 / 64. 20 / 64. 15 / 64. 1 / 64. 6 / 64. Number of - PowerPoint PPT Presentation

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Page 1: Non-Mendelian Inheritance

Non-Mendelian Inheritance

Page 2: Non-Mendelian Inheritance

Eggs

Sperm

Phenotypes:Number ofdark-skin alleles: 0 1 2 3 4 5 6

1/646/64

15/6420/64

15/646/64

1/64

1/8

1/8

1/8

1/8

1/8

1/8

1/8

1/8

1/81/8

1/81/8

1/81/8

1/81/8

AaBbCc AaBbCc

Polygenetic Inheritance-a trait is controlled by more than two alleles. Each

dominant allele has a

quantitative effect

Ex. Skin color

Page 3: Non-Mendelian Inheritance

3

Height in Human Beings

Page 4: Non-Mendelian Inheritance

4

Frequency Distributions in

Polygenic Inheritance

Page 5: Non-Mendelian Inheritance

Sex Determination-out of 46 only 2 are sex chromosomes = X &

Y-  XX = female, XY = male-44 are autosomes- code for everything else

Page 6: Non-Mendelian Inheritance
Page 7: Non-Mendelian Inheritance

Sex Linked Genes- Carried on only the X or Y chromosome - Ex: Color blindness is a recessive trait carried

only on the X chromosome (XC or Xc ). A female needs to be Xc Xc to get it, but a male only has to be Xc Y to get it. So more males are color blind.

XC XC XC Xc

XC Y Xc Y

XC Xc

XC

Y

Page 8: Non-Mendelian Inheritance

Numbers That You Should See If You Are In One Of The FollowingFour Categories: [Some Letter Choices Show No Visible Numbers]

                                            

4 Sex-Linked Traits:

 1. Normal Color Vision: A: 29,  B: 45,  C: --,  D: 26

 2. Red-Green Color-Blind: A: 70,  B: --,  C: 5,  D: --

 3. Red Color-blind: A: 70,  B: --,  C: 5,  D: 6

 4. Green Color-Blind: A: 70,  B: --,  C: 5,  D: 2

Page 9: Non-Mendelian Inheritance

Pedigree- a chart showing genetic inheritance

Page 10: Non-Mendelian Inheritance

10

Autosomal Recessive Pedigree Chart

Page 11: Non-Mendelian Inheritance

11

Autosomal Dominant Pedigree Chart

Page 12: Non-Mendelian Inheritance

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Autosomal Recessive Disorders• Tay-Sachs Disease

– Progressive deterioration of psychomotor functions. Lipid accumulation in brain cells. Death in childhood

• Cystic Fibrosis

– Mucus in bronchial tubes and pancreatic ducts is particularly thick and viscous

• Phenylketonuria (PKU)

– Lack enzyme for normal metabolism of phenylalanine. Mental retardation

Albinism- lack of pigment (melanin)

Sickle Cell (homozygous)

Page 13: Non-Mendelian Inheritance

13

Cystic Fibrosis Therapy

Page 14: Non-Mendelian Inheritance

14

Autosomal Dominant Disorders• Alzheimers (mental deterioration)

• Achondroplasia (dwarfism)

• Neurofibromatosis Tan or dark spots develop on skin and darken Small, benign tumors may arise from fibrous nerve coverings

• Huntington Disease Neurological disorder Progressive degeneration of brain cells

• Severe muscle spasms

• Personality disorders

Page 15: Non-Mendelian Inheritance

15

A Victim of Huntington Disease

Page 16: Non-Mendelian Inheritance

16

Huntington Disease:Normal and Diseased

Brain

Page 17: Non-Mendelian Inheritance

Incomplete Dominancethe alleles are blended together to form an

intermediate phenotype -    example:snap dragon color (red, white or pink)

Page 18: Non-Mendelian Inheritance

Co-Dominance- Both alleles are expressed in the

phenotype (ex. Sickle cell anemia) BB= normal cell bb=sickle cell Bb Both (carrier)

Page 19: Non-Mendelian Inheritance

Blood Type-Co-dominant:-caused by multiple alleles – 3 or more

typesA = has only A carbs. B = has only B carbs.AB = both AB carbs.O = no carbs.

GenotypeRed blood cell

appearancePhenotype

(blood group)

A

B

AB

O

Page 20: Non-Mendelian Inheritance

Fig. 14-11

IA

IB

i

A

B

none(a) The three alleles for the ABO blood groups and their associated carbohydrates

Allele Carbohydrate

GenotypeRed blood cell

appearancePhenotype

(blood group)

IAIA or IA i A

BIBIB or IB i

IAIB AB

ii O

(b) Blood group genotypes and phenotypes

Page 21: Non-Mendelian Inheritance

RH factor-Rhesus factor- antigens on the surface of blood cells that

can cause an immune response

- Positive (+) blood has antigens

- Negative (-) blood has no antigens

-a negative mother could harm a positive fetus.

-a negative person getting positive blood can be harmed

Page 22: Non-Mendelian Inheritance

Epistasis • One gene alters the expression of another gene

BbCc BbCc

Sperm

EggsBC bC Bc bc

BC

bC

Bc

bc

BBCC

1/41/4

1/41/4

1/4

1/4

1/4

1/4

BbCC BBCc BbCc

BbCC bbCC BbCc bbCc

BBCc BbCc

BbCc bbCc

BBcc Bbcc

Bbcc bbcc

9 : 3 : 4

Page 23: Non-Mendelian Inheritance

Pleiotrophy• Some genes control more than one trait. (ex. Pea

flower and seed color are controlled by one gene)

Page 24: Non-Mendelian Inheritance

Multifactorial genetics• Multifactorial traits are affected by genotype and the

environment

• Norm of reaction-phenotype range (more acid or aluminum results in darker flowers

Page 25: Non-Mendelian Inheritance

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Himalayan Rabbits