INCOMPLETE DOMINANCE n With incomplete dominance a cross

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INCOMPLETE DOMINANCE n With incomplete dominance, a cross between organisms with two different phenotypes

INCOMPLETE DOMINANCE n With incomplete dominance, a cross between organisms with two different phenotypes produces offspring with a third phenotype that is a blending of the parental traits.

INCOMPLETE DOMINANCE When the phenotype of the heterozygous is intermediate between the two homozygous

INCOMPLETE DOMINANCE When the phenotype of the heterozygous is intermediate between the two homozygous n Neither allele is dominant/recessive over the other. Neither allele will express itself---therefore NO capital or lower case letters n

INCOMPLETE DOMINANCE n n EX: Snapdragon flowers. Red flowers White flowers Pink Flowers n

INCOMPLETE DOMINANCE n n EX: Snapdragon flowers. Red flowers White flowers Pink Flowers n n When working these problems it becomes essential to make a key Red (RR) White (WW) Pink (RW)

INCOMPLETE DOMINANCE Cross a Red Snapdragon flower with a White Snapdragon flower. n Set

INCOMPLETE DOMINANCE Cross a Red Snapdragon flower with a White Snapdragon flower. n Set up the Punnett Square and give me both pheno and geno Ratios. n

INCOMPLETE DOMINANCE

INCOMPLETE DOMINANCE

INCOMPLETE DOMINANCE n Phenotypic Ratio 100% Pink n Genotypic Ratio 100% RW

INCOMPLETE DOMINANCE n Phenotypic Ratio 100% Pink n Genotypic Ratio 100% RW

INCOMPLETE DOMINANCE n You cross two pink flowers and give me both phenotypic and

INCOMPLETE DOMINANCE n You cross two pink flowers and give me both phenotypic and genotypic ratios.

CO-DOMINANT ALLELES n n Where both alleles express themselves fully. With Co-dominance, a cross

CO-DOMINANT ALLELES n n Where both alleles express themselves fully. With Co-dominance, a cross between organisms with two different phenotypes produces offspring with a third phenotype. This third phenotype has BOTH parental traits expressed.

CO-DOMINANT ALLELES n n This is most commonly seen in chickens. Cross a black

CO-DOMINANT ALLELES n n This is most commonly seen in chickens. Cross a black chicken with a white chicken you get what is called a speckled chicken NOT GRAY…but both alleles (black and white) fully express themselves so the chicken has both types of feathers.

CO-DOMINANT ALLELES n White cow crossed with a Red Bull

CO-DOMINANT ALLELES n White cow crossed with a Red Bull

CO-DOMINANT ALLELES Roan Cow…. Roan refers to cows that have red coats with white

CO-DOMINANT ALLELES Roan Cow…. Roan refers to cows that have red coats with white blotches.

CO-DOMINANT ALLELES A white horse crossed with a black stallion

CO-DOMINANT ALLELES A white horse crossed with a black stallion

CO-DOMINANT ALLELES A gray horse…but upon closer inspection it has hairs that are both

CO-DOMINANT ALLELES A gray horse…but upon closer inspection it has hairs that are both black and hairs that are white.

POLYGENIC TRAITS More than one allele pair controls a single trait— n Ex: Skin

POLYGENIC TRAITS More than one allele pair controls a single trait— n Ex: Skin Color—Several different allele pairs attribute to the overall phenotype— Tone, distribution, etc n

MULTIPLE ALLELES n n A population might have more than two alleles for a

MULTIPLE ALLELES n n A population might have more than two alleles for a given gene. In this case you have to think of a gene as a segment of your DNA that controls a trait. You have more than 2 choices for an allele for each trait. Even if more than two alleles exist in a population, any given individual can have no more than two of them.

MULTIPLE ALLELES n Ex: Blood type, Rabbit Fur, Labrador Retriever Coat Color

MULTIPLE ALLELES n Ex: Blood type, Rabbit Fur, Labrador Retriever Coat Color

MULTIPLE ALLELES n In Labs, coat color is determined by one gene with four

MULTIPLE ALLELES n In Labs, coat color is determined by one gene with four different alleles. Five different colors result from a combination of these alleles.

Phenotype Possible Genotypes BBEE Bb. EE BBEe Bb. Ee bb. EE bb. Ee BBee

Phenotype Possible Genotypes BBEE Bb. EE BBEe Bb. Ee bb. EE bb. Ee BBee Bbee bbee

Multiple Alleles- Blood Type of Preferred Permissible Recipient Blood Type of Donor A A

Multiple Alleles- Blood Type of Preferred Permissible Recipient Blood Type of Donor A A A, O B B B, O AB AB AB, A, B, O O

Multiple Alleles- Blood Type

Multiple Alleles- Blood Type

Multiple Alleles-Rabbit Fur n n Coat color in rabbits is determined by a single

Multiple Alleles-Rabbit Fur n n Coat color in rabbits is determined by a single allele pair that has at least four different alleles. Full(C), Chinchilla (Ch), Himalayan (h), Albino (c)

SEX CHROMOSOMES n We already know that each human has 46 chromosomes which means

SEX CHROMOSOMES n We already know that each human has 46 chromosomes which means they have 23 homologous pairs. n The 23 rd Pair is different. It determines the sex of the individual.

SEX CHROMOSOMES n Homologous Pairs 1 -22 are called Autosomes n The 23 pair

SEX CHROMOSOMES n Homologous Pairs 1 -22 are called Autosomes n The 23 pair often called the Sex Chromosome.

FEMALE SEX CHROMSOMES n Female 23 rd Chromosome is represented by XX.

FEMALE SEX CHROMSOMES n Female 23 rd Chromosome is represented by XX.

MALE SEX CHROMSOMES n The 23 Chromosome on the male is represented with a

MALE SEX CHROMSOMES n The 23 Chromosome on the male is represented with a XY.

SEX-LINKED TRAITS n Genes that are carried by either sex chromosome are said to

SEX-LINKED TRAITS n Genes that are carried by either sex chromosome are said to be Sex-linked Traits.

SEX-LINKED TRAITS n Scientist discovered this linkage when studying fruit flies (Drosophilia). Through many

SEX-LINKED TRAITS n Scientist discovered this linkage when studying fruit flies (Drosophilia). Through many experiments scientist soon concluded eye color of these flies were determined by the sex chromosome.

SEX-LINKED TRAITS n Often an allele for a trait can be found on the

SEX-LINKED TRAITS n Often an allele for a trait can be found on the X but not on the Y chromosome. n The Y chromosome on the male carries little or NO genetic information.

SEX-LINKED TRAITS n n n WHEN WORKING ANY SEXLINKED TRAIT YOU MUST ALWAYS WRITE

SEX-LINKED TRAITS n n n WHEN WORKING ANY SEXLINKED TRAIT YOU MUST ALWAYS WRITE IT OUT…… XX x XY You still have dominant and recessive alleles.

SEX-LINKED TRAITS n n Eye color in fruit flies is a sex-linked trait where

SEX-LINKED TRAITS n n Eye color in fruit flies is a sex-linked trait where Red eyes is dominant over White eyes. (This trait is carried on the X chromosome) Cross a heterozygous Red eyed female with a red eyed male.

SEX-LINKED TRAITS Practice Problems n n Cross a heterozygous Red eyed female with a

SEX-LINKED TRAITS Practice Problems n n Cross a heterozygous Red eyed female with a red eyed male. Cross a homozygous Red eyed female with a white eyed male. Allow the F 1 generation male/female to cross. Show me Cross, Punnett Square, and Phenotypic and Genotypic Ratio

SEX-LINKED TRAITS n Most sex-linked traits are carried on the X chromosome. Therefore the

SEX-LINKED TRAITS n Most sex-linked traits are carried on the X chromosome. Therefore the female will carry two and the male will only carry one. n However, some sex-linked traits are carried on the Y…but only a few!!

SEX-LINKED TRAITS Colorblindness n Hemophilia n Duchenne Muscular Dystrophy n Fragile X Syndrom n

SEX-LINKED TRAITS Colorblindness n Hemophilia n Duchenne Muscular Dystrophy n Fragile X Syndrom n

SEX-INFLUENCED TRAITS n n n (NOT located on X or Y chromosome)found in both

SEX-INFLUENCED TRAITS n n n (NOT located on X or Y chromosome)found in both sexes but expressed differently. Baldness-caused by autosomal allele that is dominant in men due to the presence of testosterone. It is recessive trait in women. Index finger length- Dom/fem Rec/Mal

SEX-LIMITED TRAITS Sex-limited traits are autosomal traits that are expressed in only one sex

SEX-LIMITED TRAITS Sex-limited traits are autosomal traits that are expressed in only one sex (In normal conditions) n Ex: Breast, Beards, Breast milk. n

TESTCROSS n Testcross- one way to determine the genotype of an unknown genotype is

TESTCROSS n Testcross- one way to determine the genotype of an unknown genotype is to cross it with a known genotype (usually recessive)

TESTCROSS n A breeder is considering using this dog to produce offspring. However the

TESTCROSS n A breeder is considering using this dog to produce offspring. However the owner is unsure if the dog is a possible carrier of a common hearing problem. She knows that he has normal hearing. What can she do?

Carrier n A carrier is a heterozygous individual. They do NOT have the trait

Carrier n A carrier is a heterozygous individual. They do NOT have the trait but do have the possibility to pass it to their offspring. Dd

TESTCROSS n When performing a test cross you would cross the unknown genotype with

TESTCROSS n When performing a test cross you would cross the unknown genotype with a known…usually a homozygous recessive. n Many breeders will rely on a testcross to determine if they are dealing with a pure breed or a hybrid.

PEDIGREE n A graphic representation of an individuals family tree.

PEDIGREE n A graphic representation of an individuals family tree.

KAROTYPE n n n A photograph that shows an individuals chromosomes in homologous pairs.

KAROTYPE n n n A photograph that shows an individuals chromosomes in homologous pairs. Usually done by collecting white blood cells-stimulating mitosis and capture the information. Karotype can be used to find any chromosomal abnormality.

KAROTYPE n n Most abnormalities are called by Nondisjuction- the failure of one or

KAROTYPE n n Most abnormalities are called by Nondisjuction- the failure of one or more chromosomes pairs to separate during meiosis. Down Syndrome Klinefelter Syndrome Turner Syndrome