Learning Target Determine the relationship between DNA genes

§ Learning Target: Determine the relationship between DNA, genes, chromosomes, and the nucleus Science Starter: Pg. 40—Read and summarize 7. 14 A

Turn to Pg. 19 in Genetics Workbook

Genetics: The study of heredity

Heredity = the passing of traits from parents to offspring

Heredity = the passing of traits from parents to offspring § Trait = A feature or characteristic of a person § Physical appearance § Behavior tendencies § Predisposed to medical conditions § A person’s traits are influenced by: § their genetic inheritance § environmental factors What is a trait?

Trait = a feature or characteristic of a person § Physical appearance § Genetics: § Environment: hair color hair texture eye color face shape smile shape

Trait = a feature or characteristic of a person § Physical appearance § Genetics: genes determine natural hair color § Environment: hair color hair texture eye color face shape smile shape

Trait = a feature or characteristic of a person § Physical appearance § Genetics: genes determine natural hair color § Environment: sun or hair dyes change hair color hair texture eye color face shape smile shape

Trait = a feature or characteristic of a person § Behavior tendencies § Genetics: § Environment:

Trait = a feature or characteristic of a person § Behavior tendencies § Genetics: genes determine the tendency to use a certain hand § Environment:

Trait = a feature or characteristic of a person § Behavior tendencies § Genetics: genes determine the tendency to use a certain hand § Environment: can learn to use the opposite hand

Trait = a feature or characteristic of a person § Predisposed to medical conditions § Genetics: § Environment:

Trait = a feature or characteristic of a person § Predisposed to medical conditions § Genetics: genes determine a risk of heart disease § Environment:

Trait = a feature or characteristic of a person § Predisposed to medical conditions § Genetics: genes determine a risk of heart disease § Environment: eating healthy foods and exercising can reduce risk

Trait = a feature or characteristic of a person § Phenotype = a person’s version of a trait § “physical appearance” hair color: black hair texture: straight eye color: blue

Practice § List 3 traits Dash has. § List Dash’s phenotype for each trait.

Trait = a feature or characteristic of a person § Gene = part of a person’s DNA that influences a trait Eye color gene Face shape gene Hair color gene

Gene = part of a person’s DNA that controls a trait § Alleles= different versions of a gene Eye color gene: brown allele Eye color gene: blue allele

Practice § List 3 possible alleles for the hair color gene. Hair color gene

Alleles = different versions of a gene § Dominant Allele § Represented by a capital letter § Example: B for brown eyes § Recessive allele § Represented by a lowercase letter § Example: b for blue eyes

Alleles = different versions of a gene § All people have 2 alleles for every gene (one from each parent) Allele of eye color gene from dad Allele of eye color gene from mom

Alleles = different versions of a gene § All people have 2 alleles for every gene (one from each parent) § Genotype = a person’s combination of alleles § “genetic makeup” Allele of eye color gene from dad Allele of eye color gene from mom

Genotype = a person’s combination of alleles § A person may inherit 2 of the same alleles = purebred § 2 dominant alleles = purebred dominant § Example: B and B Genotype = Phenotype = Mom Dad E E Child

Genotype = a person’s combination of alleles § A person may inherit 2 of the same alleles = purebred § 2 dominant alleles = purebred dominant § Example: B and B Genotype = BB Phenotype = Mom Dad E E Child

Genotype = a person’s combination of alleles § A person may inherit 2 of the same alleles = purebred § 2 dominant alleles = purebred dominant § Example: B and B Mom Dad Genotype = BB Phenotype = brown eyes E E Child

Genotype = a person’s combination of alleles § A person may inherit 2 of the same alleles = purebred § 2 recessive alleles = Mom Dad e e Child

Genotype = a person’s combination of alleles § A person may inherit 2 of the same alleles = purebred § 2 recessive alleles = purebred recessive § Example: b and b Genotype = Phenotype = Mom Dad e e Child

Genotype = a person’s combination of alleles § A person may inherit 2 of the same alleles = purebred § 2 recessive alleles = purebred recessive § Example: b and b Genotype = bb Phenotype = Mom Dad e e Child

Genotype = a person’s combination of alleles § A person may inherit 2 of the same alleles = purebred § 2 recessive alleles = purebred recessive § Example: b and b Genotype = bb Phenotype = blue eyes Mom Dad e e Child

Alleles = different versions of a gene § A person may inherit 2 different alleles = hybrid § Dominant allele masks recessive allele § Example: B and b Genotype = Mom Dad E e Child Phenotype = -or- Mom Dad e E Child

Alleles = different versions of a gene § A person may inherit 2 different alleles = hybrid § Dominant allele masks recessive allele § Example: B and b Genotype = Bb Mom Dad E e Child Phenotype = -or- Mom Dad e E Child

Alleles = different versions of a gene § A person may inherit 2 different alleles = hybrid § Dominant allele masks recessive allele § Example: B and b Genotype = Bb Mom Dad E e Child Phenotype = brown eyes -or- Mom Dad e E Child

Practice § Brown hair (B) is dominant to blond hair (b). Genotype purebred dominant purebred recessive hybrid Phenotype

Practice § Brown hair (B) is dominant to blond hair (b). Genotype purebred dominant purebred recessive hybrid BB Phenotype Brown hair

Practice § Brown hair (B) is dominant to blonde hair (b). Genotype Phenotype purebred dominant BB Brown hair purebred recessive bb Blond hair hybrid

Practice § Brown hair (B) is dominant to blond hair (b). Genotype Phenotype purebred dominant BB Brown hair purebred recessive bb Blond hair hybrid Bb Brown hair Which genotypes are purebred? Which is hybrid?

Practice § Right-handedness (R) is dominant to left-handedness (r). What genotype(s) could a right-handed person have? RR or Rr What genotype(s) could a left-handed person have? rr

Practice § In pea plants, green peas (G) are dominant to yellow peas (g). What would be the genotype of a: -purebred green pea? GG -hybrid green pea? Gg -yellow pea? gg

Exit ticket § Answer questions 1 and 2 on pg 41 of the Genetics Workbook. § Please show Mrs. Hinds or Mrs. Chew your work!!!