Grade 10

Biology

Genetics and Inheritance

Patterns

Mr Kremer

Grade 10

Biology

Genetics and Inheritance

Patterns

Mr Kremer

Genetics: Key concepts

• Mendel’s experiments with pea plants

• Dominant, recessive, + codominant traits

• Sex linkage of genetic disorders

• Biotechnology + its consequences

Mendellian Genetics

Mendellian Genetics

Gregor Mendel + his pea plants

Alleles + traitsDominant, recessive, +

codominantHeterozygous + homozygous

Phenotype + genotype

Gregor Mendel + His Work

• 1800‘s monk

Gregor Mendel + His Work

• 1800‘s monk

• Systematically bred pea plants

Gregor Mendel + His Work

• 1800‘s monk

• Systematically bred pea plants

Gregor Mendel + His Work

• 1800‘s monk

• Systematically bred pea plants

Gregor Mendel + His Work

• 1800‘s monk

• Systematically bred pea plants

Gregor Mendel + His Work

• 1800‘s monk

• Systematically bred pea plants

• Identified patterns in offspring

Gregor Mendel + His Work

• 1800‘s monk

• Systematically bred pea plants

• Identified patterns in offspring

• Developed Law of Segregation and Law of Independent Assortment

Gregor Mendel + His Work

• 1800‘s monk

• Systematically bred pea plants

• Identified patterns in offspring

• Developed Law of Segregation and Law of Independent Assortment

Inheritance Patterns

Dominant +

Recessive Traits

Alleles, chromosomes, + lociTraits + characteristicsDominant vs recessive

Heterozygous + homozygousMonohybrid cross

Essential Vocabulary• Locus = place on a

chromosome where a specific gene is found

• Gene = combination of alleles controlling a trait

• Allele = one form of a gene (basically, half a gene)

from Mom

!

from

Dad

!

Essential Vocabulary• Genotype =

allelic composition

• Phenotype = physical expression of genotype

• Bb = genotype

• brown eyes = phenotype

Dominant + Recessive Traits

• Dominant = always expressed

• Recessive = only expressed if homozygous

Dominant + Recessive Traits

• Dominant = always expressed

• Recessive = only expressed if homozygous

• Homozygous = both alleles are the same

Dominant + Recessive Traits

• Dominant = always expressed

• Recessive = only expressed if homozygous

• Homozygous = both alleles are the same

• Heterozygous = different alleles

Dominant + Recessive Traits

• Dominant = always expressed

• Recessive = only expressed if homozygous

• Homozygous = both alleles are the same

• Heterozygous = different alleles

Monohybrid Crosses• Show probability of

offspring inheriting a trait

• Alleles listed along x- and y-axes

• Combine alleles in boxes to show possible genotypes

• Genotypes determine phenotypes

Monohybrid Crosses• Show probability of

offspring inheriting a trait

• Alleles listed along x- and y-axes

• Combine alleles in boxes to show possible genotypes

• Genotypes determine phenotypes

Monohybrid Crosses• Show probability of

offspring inheriting a trait

• Alleles listed along x- and y-axes

• Combine alleles in boxes to show possible genotypes

• Genotypes determine phenotypes

Monohybrid Crosses• Show probability of

offspring inheriting a trait

• Alleles listed along x- and y-axes

• Combine alleles in boxes to show possible genotypes

• Genotypes determine phenotypes

Monohybrid Crosses• Show probability of

offspring inheriting a trait

• Alleles listed along x- and y-axes

• Combine alleles in boxes to show possible genotypes

• Genotypes determine phenotypes

Monohybrid Crosses• Show probability of

offspring inheriting a trait

• Alleles listed along x- and y-axes

• Combine alleles in boxes to show possible genotypes

• Genotypes determine phenotypes

Monohybrid Crosses• Show probability of

offspring inheriting a trait

• Alleles listed along x- and y-axes

• Combine alleles in boxes to show possible genotypes

• Genotypes determine phenotypes

Monohybrid Crosses• Show probability of

offspring inheriting a trait

• Alleles listed along x- and y-axes

• Combine alleles in boxes to show possible genotypes

• Genotypes determine phenotypes

Monohybrid Crosses• Show probability of

offspring inheriting a trait

• Alleles listed along x- and y-axes

• Combine alleles in boxes to show possible genotypes

• Genotypes determine phenotypes

Monohybrid Crosses• Show probability of

offspring inheriting a trait

• Alleles listed along x- and y-axes

• Combine alleles in boxes to show possible genotypes

• Genotypes determine phenotypes

Monohybrid Crosses• Show probability of

offspring inheriting a trait

• Alleles listed along x- and y-axes

• Combine alleles in boxes to show possible genotypes

• Genotypes determine phenotypes

3:1

ratio

3:1

ratio

Monohybrid Crosses

Codominance + Blood Types

Codominance + Blood

TypesCodominance

Incomplete dominanceBlood types

Crosses involving codominant traits

Image credit: http://www.joannelovesscience.com

Codominance + Incomplete Dominance

• Codominance = both heterozygous alleles fully expressed

Codominance + Incomplete Dominance

• Codominance = both heterozygous alleles fully expressed

Codominance + Incomplete Dominance

• Codominance = both heterozygous alleles fully expressed

Codominance + Incomplete Dominance

• Codominance = both heterozygous alleles fully expressed

• Incomplete dominance = a blend of each characteristic is expressed

Codominance + Blood Types

• 3 blood type alleles:

• IA = Type A

• IB = Type B

• i = Type O

• A + B = codominant

• O is recessive

Codominance + Blood Types

• 3 blood type alleles:

• IA = Type A

• IB = Type B

• i = Type O

• A + B = codominant

• O is recessive

Codominance + Blood Types

• 3 blood type alleles:

• IA = Type A

• IB = Type B

• i = Type O

• A + B = codominant

• O is recessive

Codominance + Blood Types

• 3 blood type alleles:

• IA = Type A

• IB = Type B

• i = Type O

• A + B = codominant

• O is recessive

Codominance + Blood Types

• 3 blood type alleles:

• IA = Type A

• IB = Type B

• i = Type O

• A + B = codominant

• O is recessive

Sex Linkage

Sex Linkage

Sex LinkageX + Y chromosomes

ColorblindnessHemophilia

Image credit: http://www.biologycorner.com

Sex Linkage

• Gene carried on X chromosome

• Women = XX

• Men = XY

• women need 2 copies of recessive allele

• men need only 1 copy

Sex Linkage

• Gene carried on X chromosome

• Women = XX

• Men = XY

• women need 2 copies of recessive allele

• men need only 1 copy

Sex Linkage

• Gene carried on X chromosome

• Women = XX

• Men = XY

• women need 2 copies of recessive allele

• men need only 1 copy

Sex Linkage

• Colorblindness

Sex Linkage

• Hemophilia

Genetic Disorders

Genetic Disorders

• Caused by gene variation or mutation

• Environmental mutation

• Inherited as recessive alleles

• Wrong number of chromosomes

Genetic Disorders

• Caused by gene variation or mutation

• Environmental mutation

• Inherited as recessive alleles

• Wrong number of chromosomes

Genetic Disorders

• Caused by gene variation or mutation

• Environmental mutation

• Inherited as recessive alleles

• Wrong number of chromosomes

Genetic Disorders

• Caused by gene variation or mutation

• Environmental mutation

• Inherited as recessive alleles

• Wrong number of chromosomes

Genetic Disorders

• Caused by gene variation or mutation

• Environmental mutation

• Inherited as recessive alleles

• Wrong number of chromosomes

Biotechnology

Biotechnology

Genetic screeningDNA profiling

GMO’sStem cell research

Genetic Screening

• Examine DNA for genetic disorders

• Good for preventative care + treatment

• Ethics of use for insurance + health care?

• May be used in job placement

Genetic Screening

• Examine DNA for genetic disorders

• Good for preventative care + treatment

• Ethics of use for insurance + health care?

• May be used in job placement

Genetic Screening

• Examine DNA for genetic disorders

• Good for preventative care + treatment

• Ethics of use for insurance + health care?

• May be used in job placement

Genetic Screening

• Examine DNA for genetic disorders

• Good for preventative care + treatment

• Ethics of use for insurance + health care?

• May be used in job placement

DNA Profiling

• aka DNA fingerprinting

• Compare samples to database

• Forensics (CSI)

• Questions about legality/ownership of information

DNA Profiling

• aka DNA fingerprinting

• Compare samples to database

• Forensics (CSI)

• Questions about legality/ownership of information

Genetically Modified Organisms

• Inserting/deleting genes for human benefit

• Common in US agriculture

• Benefits: higher yield + productivity

• Concerns: ecological dangers, loss of diversity

Genetically Modified Organisms

• Inserting/deleting genes for human benefit

• Common in US agriculture

• Benefits: higher yield + productivity

• Concerns: ecological dangers, loss of diversity

Genetically Modified Organisms

• Inserting/deleting genes for human benefit

• Common in US agriculture

• Benefits: higher yield + productivity

• Concerns: ecological dangers, loss of diversity

Genetically Modified Organisms

• Inserting/deleting genes for human benefit

• Common in US agriculture

• Benefits: higher yield + productivity

• Concerns: ecological dangers, loss of diversity

Genetically Modified Organisms

• Inserting/deleting genes for human benefit

• Common in US agriculture

• Benefits: higher yield + productivity

• Concerns: ecological dangers, loss of diversity