Complete Dominance Pattern of Inheritance and Punnett Squares
Pattern of Inheritance a description of how contrasting genes on homologous chromosomes interact with one another when two alleles are different, how do they affect the phenotype
Complete Dominance Pattern when different genes are present in one organism (a heterozygous individual), only one gene is visible in the organism’s phenotype the dominant gene is visible while the recessive gene is “hidden”
Punnett Square a diagram that predicts the outcome of a genetic cross by considering all possible combinations of gametes in the cross
Punnett Square
Studying Heredity Holt Biology, pg. 170
Monohybrid Cross examining the offspring genotype and phenotype possibilities for one gene
Punnett Squares and the Law of Segregation Punnett Squares show two alleles from one parent splitting up demonstrates Mendel’s Law of Segregation homologous chromosomes that carry the same genes split during Meiosis 1 allows offspring created to have one allele for each gene from each parent
Studying Heredity Holt Biology, pg. 170
Punnett Square
Mendel’s Pea Plants’ Flowers Parent Generation Cross Identification of Alleles P = purple p = white Parent Genotype Identification Purple parent: PP White parent: pp
Parent Generation Cross Punnett Square
Parent Generation Cross Punnett Square
Parent Generation Cross Punnett Square
Parent Generation Cross Punnett Square Pp p p
Parent Generation Cross Punnett Square Pp p p
Parent Generation Cross Punnett Square Pp p p
Parent Generation Cross Punnett Square Pp p p
Parent Generation Cross Offspring Genotypic Ratio 4/4 or all or 100 % Pp Offspring Phenotypic Ratio 4/4 or all or 100 % purple
Studying Heredity Holt Biology, pg. 164
Mendel’s Pea Plants’ Flowers F1 Generation Cross Identification of Alleles P = purple p = white Parent Genotype Identification F1 Generation Purple Plant 1: Pp F1 Generation Purple Plant 2: Pp
F1 Generation Cross Punnett Square
F1 Generation Cross Punnett Square
F1 Generation Cross Punnett Square
F1 Generation Cross Punnett Square PP P p
F1 Generation Cross Punnett Square PP Pp P p
F1 Generation Cross Punnett Square PP Pp P p
F1 Generation Cross Punnett Square PP Pp pp P p
F1 Generation Cross Offspring Genotypic Ratio 1 PP : 2 Pp : 1 pp Offspring Phenotypic Ratio 3 purple : 1 white
What would the offspring represented in these boxes be called What would the offspring represented in these boxes be called? Punnett Square P p PP Pp pp P p F2 Generation
In garden peas, long stems (L) are dominant and short stems (l) are recessive. If a homozygous long plant is crossed with a homozygous short plant, what will the genotypic and phenotypic ratios be? Identification of Alleles L = long stems l = short stems Parent Genotype Identification LL ll
In garden peas, long stems (L) are dominant and short stems (l) are recessive. If a homozygous long plant is crossed with a homozygous short plant, what will the genotypic and phenotypic ratios be? Punnett Square L L l l
In garden peas, long stems (L) are dominant and short stems (l) are recessive. If a homozygous long plant is crossed with a homozygous short plant, what will the genotypic and phenotypic ratios be? Punnett Square L L Ll l l
In garden peas, long stems (L) are dominant and short stems (l) are recessive. If a homozygous long plant is crossed with a homozygous short plant, what will the genotypic and phenotypic ratios be? Punnett Square L L Ll l l
In garden peas, long stems (L) are dominant and short stems (l) are recessive. If a homozygous long plant is crossed with a homozygous short plant, what will the genotypic and phenotypic ratios be? Punnett Square L L Ll l l
In garden peas, long stems (L) are dominant and short stems (l) are recessive. If a homozygous long plant is crossed with a homozygous short plant, what will the genotypic and phenotypic ratios be? Punnett Square L L Ll l l
In garden peas, long stems (L) are dominant and short stems (l) are recessive. If a homozygous long plant is crossed with a homozygous short plant, what will the genotypic and phenotypic ratios be? Offspring Genotypic Ratio 4/4 or all or 100% Ll Offspring Phenotypic Ratio 4/4 or all or 100% long stems
What will the genotypic and phenotypic ratios be if we cross the F1 (offspring) from the previous problem? Identification of Alleles L = long stems l = short stems Parent Genotype Identification Ll
What will the genotypic and phenotypic ratios be if we cross the F1 (offspring) from the previous problem? Punnett Square L l L l
What will the genotypic and phenotypic ratios be if we cross the F1 (offspring) from the previous problem? Punnett Square L l LL L l
What will the genotypic and phenotypic ratios be if we cross the F1 (offspring) from the previous problem? Punnett Square L l LL Ll L l
What will the genotypic and phenotypic ratios be if we cross the F1 (offspring) from the previous problem? Punnett Square L l LL Ll L l
What will the genotypic and phenotypic ratios be if we cross the F1 (offspring) from the previous problem? Punnett Square L l LL Ll ll L l
What will the genotypic and phenotypic ratios be if we cross the F1 (offspring) from the previous problem? Offspring Genotypic Ratio 1 LL : 2 Ll : 1 ll Offspring Phenotypic Ratio 3 long stems : 1 short stem
Identification of Alleles Parent Genotype Identification In garden peas inflated pods are dominant to constricted pods. Cross a plant that is heterozygous for inflated pea pods with a plant that is homozygous for constricted pea pods. What are the genotypes and phenotypes? Identification of Alleles Parent Genotype Identification
The Work of Gregor Mendel (a little background information…) Holt Biology, pg. 163
Identification of Alleles Parent Genotype Identification In garden peas inflated pods are dominant to constricted pods. Cross a plant that is heterozygous for inflated pea pods with a plant that is homozygous for constricted pea pods. What are the genotypes and phenotypes? Identification of Alleles Parent Genotype Identification
When no letters are assigned to different alleles, what should you do? Make them up! What are “typical” letters to use? Most often, the first letter of a term that describes the dominant trait is used.
In garden peas inflated pods are dominant to constricted pods In garden peas inflated pods are dominant to constricted pods. Cross a plant that is heterozygous for pea pods with a plant that is homozygous for inflated pea pods. What are the genotypes and phenotypes? Identification of Alleles I = inflated pea pods i = constricted pea pods Parent Genotype Identification Ii II
In garden peas inflated pods are dominant to constricted pods In garden peas inflated pods are dominant to constricted pods. Cross a plant that is heterozygous for pea pods with a plant that is homozygous for inflated pea pods. What are the genotypes and phenotypes? Punnett Square I i I I
In garden peas inflated pods are dominant to constricted pods In garden peas inflated pods are dominant to constricted pods. Cross a plant that is heterozygous for pea pods with a plant that is homozygous for inflated pea pods. What are the genotypes and phenotypes? Punnett Square I i II I I
In garden peas inflated pods are dominant to constricted pods In garden peas inflated pods are dominant to constricted pods. Cross a plant that is heterozygous for pea pods with a plant that is homozygous for inflated pea pods. What are the genotypes and phenotypes? Punnett Square I i II Ii I I
In garden peas inflated pods are dominant to constricted pods In garden peas inflated pods are dominant to constricted pods. Cross a plant that is heterozygous for pea pods with a plant that is homozygous for inflated pea pods. What are the genotypes and phenotypes? Punnett Square I i II Ii I I
In garden peas inflated pods are dominant to constricted pods In garden peas inflated pods are dominant to constricted pods. Cross a plant that is heterozygous for pea pods with a plant that is homozygous for inflated pea pods. What are the genotypes and phenotypes? Punnett Square I i II Ii I I
Offspring Genotypic Ratio 2 II : 2 Ii Offspring Phenotypic Ratio In garden peas inflated pods are dominant to constricted pods. Cross a plant that is heterozygous for pea pods with a plant that is homozygous for inflated pea pods. What are the genotypes and phenotypes? Offspring Genotypic Ratio 2 II : 2 Ii Offspring Phenotypic Ratio
When numbers have a common factor, simplify them in the ratio.
Offspring Genotypic Ratio 2 II : 2 Ii Offspring Phenotypic Ratio In garden peas inflated pods are dominant to constricted pods. Cross a plant that is heterozygous for pea pods with a plant that is homozygous for inflated pea pods. What are the genotypes and phenotypes? Offspring Genotypic Ratio 2 II : 2 Ii Offspring Phenotypic Ratio
In garden peas inflated pods are dominant to constricted pods In garden peas inflated pods are dominant to constricted pods. Cross a plant that is heterozygous for pea pods with a plant that is homozygous for inflated pea pods. What are the genotypes and phenotypes? Offspring Genotypic Ratio 2 II : 2 Ii 1 II : 1 Ii Offspring Phenotypic Ratio 4/4 or all or 100% inflated pea pods
What will the genotypic and phenotypic ratios be if garden pea plants which have heterozygous inflated pods and constricted pods are crossed? Identification of Alleles I = inflated pea pods i = constricted pea pods Parent Genotype Identification Ii
How will you know the genotype of the constricted pea pod parent? When a recessive trait is visible in the phenotype, only 1 genotype of possible Homozygous recessive
What will the genotypic and phenotypic ratios be if garden pea plants which have heterozygous inflated pods and constricted pods are crossed? Identification of Alleles I = inflated pea pods i = constricted pea pods Parent Genotype Identification Ii ii
What will the genotypic and phenotypic ratios be if garden pea plants which have heterozygous inflated pods and constricted pods are crossed? Punnett Square I i i i
What will the genotypic and phenotypic ratios be if garden pea plants which have heterozygous inflated pods and constricted pods are crossed? Punnett Square I i Ii i i
What will the genotypic and phenotypic ratios be if garden pea plants which have heterozygous inflated pods and constricted pods are crossed? Punnett Square I i Ii ii i i
What will the genotypic and phenotypic ratios be if garden pea plants which have heterozygous inflated pods and constricted pods are crossed? Punnett Square I i Ii ii i i
What will the genotypic and phenotypic ratios be if garden pea plants which have heterozygous inflated pods and constricted pods are crossed? Punnett Square I i Ii ii i i
What will the genotypic and phenotypic ratios be if garden pea plants which have heterozygous inflated pods and constricted pods are crossed? Offspring Genotypic Ratio 1 Ii : 1 ii Offspring Phenotypic Ratio 1 inflated pea pod : 1 constricted pea pod