Unit 3A Human Diversity and Change Inheritance Polygenic and multi-allelic inheritance.

Slides:



Advertisements
Similar presentations
Human Genetics Inheritance Patterns for Autosomal and Sex-Linked Genes Variations in Genetic Patterns.
Advertisements

Inheritance HBS3A. Inheritance Organisms inherit characteristics from their parents Characteristics are controlled by DNA In asexual reproduction, organisms.
Biology 2B Inheritance. Organisms inherit characteristics from their parents Characteristics are controlled by DNA In asexual reproduction, organisms.
Mendelian Exceptions Chapter 12 Section 4.
Genetics Chapters 9-1 & 9-2. Incomplete dominance There is no dominant allele or recessive allele The 2 alleles are blended and make up a new physical.
Advanced Genetics.
Continuing Genetics DOMINANCE Unit 5: Mendelian Genetics
Patterns of Inheritance. Dominant Vs. Recessive Dominant gene will always be displayed Recessive gene can “Skip” Generations Need 2 copies of recessive.
Multiple Alleles Genetics Unit Biology 30 Mrs. S. Pipke-Painchaud.
Genetics – the branch of biology that studies heredity Heredity – the passing on of traits from parent to offspring Chromosomes – the genetic material.
CO-DOMINANT ALLELES: BLOOD TYPES.  BOTH alleles are expressed, even when the genotype is heterozygous  Both alleles are represented by capital lettersEX:
Variations of Inheritance Patterns Chapter 10, Section 3.
Chapter 4: Modification of Mendelian Ratios Allele *Wild-type allele *Mutant allele Conventional symbols for alleles: recessive allele - initial letter.
Chapter 11 Advanced Genetics
Blood Types and Sex-linkage
Ch. 10.3: Exceptions to Mendel’s Rules of Inheritance Objectives: 1.Describe how alleles interact in intermediate inheritance. 2.Describe inheritance patterns.
Variations of Inheritance Patterns
Variations to Inheritance Exceptions to Mendel’s Laws.
4/11/ 12 Bell Ringer 1.What does incomplete dominance mean? 2.If I had a Red Homozygous Flower and a White Homozygous Flower, what would the Heterozygous.
Recessive Alleles Takes two alleles to be expressed.
Non-Mendelian Genetics Thus far, all of the genes which we have studied have had only 2 possible forms or ALLELES. (Brown or white, tall or short, freckled.
Polygenetic inheritance
There is no dominant allele, There is no recessive allele. Both alleles “blend” to result in a third phenotype.
Blood Types.
1/6/12 Objective: What factors influence typical inheritance? Do Now: -Take out Cyclops problem.
Beyond Dominant and Recessive Alleles. The whole story... Not all phenotypes are dictated by dominant and recessive alleles (in fact, very few are). Some.
Chapter 4: Modification of Mendelian Ratios Allele *Wild-type allele *Mutant allele Conventional symbols for alleles: recessive allele- initial letter.
Chapter 11 Advanced Genetics Codominance Multiple Allele Traits Polygenic Inheritance Lethal Alleles Epistatic Alleles.
10.3 Variations of Inheritance Pg Codominance 1 gene with 2 allele variations 3 phenotypes ( outward appearance) Genotypes are written with capital.
Multiple Alleles Human Blood Types.
Chapters 6 and 7; Patterns of Heredity
6d. Blood Typing Chapter 7.1 & 7.2.
Polygenic inheritance
10.3 Polygenic Inheritance
& polygenic inheritance
28N Multiple Alleles.
Other Types of Inheritance
Polygenic Inheritance
Multiple Alleles & Polygenic Traits
Blood Typing (3R).
Genetic Inheritace.
Other Patterns of Inheritance
KEY CONCEPT Phenotype is affected by many different factors.
Can you figure out where our buzzwords go??
Punnett Squares: Part 2.
Variations of Inheritance
Complex Patterns of Inheritance
Complex Patterns of Inheritance
NonMendelian Genetics
COMPLEX PATTERNS OF HEREDITY
Exceptions to Mendel’s Discoveries
Exploring Mendelian Genetics
Can you figure out where our buzzwords go??
4/11/ 12 Bell Ringer What does incomplete dominance mean?
Other types of Inheritance
11.3: Other Patterns of Inheritance
Blood Type and Multiple Alleles
C-Notes: Patterns of Inheritance (Variations on Mendel’s Law)
The Post-Mendel Era Exceptions to Mendel.
Mendelian Exceptions Chapter 11 Section 3.
Simple Dominance One trait is completely dominant to the other
Chapter 6, Section 1 Human Inheritance.
Special Inheritance Patterns
Incomplete and Codominance
KEY CONCEPT Phenotype is affected by many different factors.
Blood Type and Multiple Alleles
NOTES 22 – Complex Inheritance Patterns
The Post-Mendel Era Exceptions to Mendel.
Probability and Punnett Squares
Incomplete & Co-dominance
Presentation transcript:

Unit 3A Human Diversity and Change Inheritance Polygenic and multi-allelic inheritance

Study Guide Read: Our Human Species (3 rd edtn) Chapter 10, section 16 Chapter 18, sections , 6.11 Complete: Human Biological Science Workbook Topic 16 – Modes of Inheritance

Polygenic inheritance Polygenic traits are determined by more than one pair of genes. Polygenic phenotypes exhibit continuous variation, since each different gene permutation results in just a small phenotypic change. Many medical conditions such as autism, cancer and type 2 diabetes are polygenic.

Polygenic phenotypes Polygenic inheritance is responsible for many phenotypic traits. Examples include skin pigmentation, height, intelligence and stature. ( note that these traits all result from the interaction of the genes with environmental factors )

Skin Colour Determination of skin colour is an example of polygenic inheritance. Skin colour is determined by at least three pairs of genes (possibly many more). For example, let the allelic forms of the three genes be: A/a, B/b, C/c Phenotype (skin colour) Genotype Dark skin Intermediate skin Light skin AA, BB, CC Aa, Bb, Cc aa,bb,cc

Multiple alleles Some genes have more than two allelic forms. These different forms of a single gene are referred to as multiple alleles. Multiple alleles can result in the blending of phenotypes.

ABO blood group system

The ABO blood group system The ABO blood group system is a way of classifying blood based on the presence or absence of two antigens on the red blood cells. Three allelic forms of a single gene are responsible for the ABO system. A person’s ABO blood group is determined by which two of the three possible alleles they inherit from their parents.

Possible phenotypes & genotypes PhenotypesGenotypes AI A I A, I A i O BI B I B, I B i O ABIAIBIAIB OiOiOiOiO The three alleles of the gene are represented by the symbols IA, IB & i o The IA & IB alleles are co-dominant – both are dominant to the i o allele (IA = IB > i o )

Blood group A – red blood cells carry A antigen Blood group B – red blood cells carry B antigen Blood group AB – red blood cells carry A & B antigens Blood group O– red blood cells carry no antigen Blood group ABlood group BBlood group ABBlood group O A A AABB B B B B AA

A person’s ABO blood group determines who they can donate blood to, or who’s blood they can receive. Blood group AntigensCan give blood to Can receive blood from AAA, ABA, O BBB, ABB, O ABA + BABA, B, AB, O OnoneA, B, AB, OO

The rhesus factor The most common blood type in Australia is O +, the rarest is AB -. The symbols + and – indicate whether the D (rhesus) antigen is present on the red blood cells: + indicates that the antigen is present and – indicates that it’s absent. The inheritance of the D antigen is polygenic and is determined by at least three pairs of genes at different loci on the same chromosome.