g10 genetics
DESCRIPTION
These are the key concepts for the genetics unit of the grade 10 biology sequence.TRANSCRIPT
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