Section 11-3 Exploring Mendelian Genetics
Dec 13, 2015
Wanted To Know If:Segregation Was Truly
Independent or Does The Segregation Of One Pair Of Alleles Affect
The Segregation Of Another Pair Of Alleles????
Mendel Performed ATwo Factor Cross
He Crossed
Round/Yellow RRYYWith Wrinkled/Green rryy
This Provided The F1 Hybrids That He Needed.
To make a Punnet square of a cross with two traits first figure out the possible gametes.
RRYY All gametes would be RYrryy All gametes would be ry
556556 Seeds ProducedSeeds Produced
315 Round/Yellow315 Round/Yellow FF11 Parental ParentalPhenotypesPhenotypes32 Wrinkled/Green32 Wrinkled/Green
PlusPlus
209 Unique Phenotypes209 Unique Phenotypes Can Only FormCan Only Form
ViaVia
9:3:3:19:3:3:1 IndependentIndependent
AssortmentAssortment
The Alleles For Seed Shape And Color Segregated
IndependentlyINDEPENDENT ASSORTMENT did occur.
Therefore These Alleles DO NOT
Influence Each Others Inheritance
The Principle Of Independent Assortment States That
Genes For Different TraitsCan Segregate
Independently During The Formation Of Gametes.
1. Inheritance of Biological Characteristics Is Determined By Individual Units Known As Genes.
In Organisms That Reproduce Sexually, Genes Are Passed From Parents To Their Offspring.
2. Where Two or More Forms Of The Alleles Exist,
Some Forms Of The Allele Many Be
DominantAnd Others May Be
Recessive.
3. In Most Sexually Reproducing Organisms, Each Adult Has Two Alleles In Each Gene – One From Each Parent
4. These Alleles Are Segregated From Each Other When Gametes Are Formed.
Key Concept:Some Alleles Are Neither Dominant Nor Recessive, And Many Traits Are Controlled By Multiple Alleles or Genes.
Red Flower Crossed With White Flower Results In Pink Flower.
In Incomplete Dominance The Heterozygous Phenotype Is Between The Homozygous
Phenotypes.(Both Alleles Expressed In One Cell)
Both Alleles Completely ExpressedRed Hair Cattle Crossed With White Haired Cattle Produce
Roan (Pink Brown) Cattle That Have Both Colored
Hairs.(Both Alleles Expressed Independently)
A Gene Is Controlled By >2 Alleles. Individuals Can Only Have 2 Alleles Populations Can Have More Than Two
Rabbit Fur Color Blood Types Eye Color