Vocabulary
Mendelian Genetics (Complete Dominance)
Incomplete Dominance
Codominance/X-Linked Traits
Multiple Alleles & Polygenic Traits
100
Define allele
Different versions of the same gene
100
What percentage of the offspring show the dominant phenotype?
100%
100
Define incomplete dominance
One allele doesn't complete dominate another -- resulting in heterozygous blend (hybrid)
100
DOUBLE JEOPARDY
How is the phenotype expressed in codominance?
Provide a real world example
Both traits are fully and separately expressed
EX: Spotted chickens
100
Define multiple alleles
Having more than two alleles for one gene
200
Define carrier
Someone who carries the recessive trait but don’t show it due to having a dominant X to mask it
200
Define Mendelian genetics
Simple inheritance patterns where dominant alleles mask recessive alleles.
Either or traits
200
How would you write alleles to show incomplete dominance?
(what symbol/letters)
AA, A'A', AA'
200
Define codominance
Two different alleles are fully & equally expressed n an individual's phenotype.
200
Explain why blood types are an example of multiple Alleles?
Because they are determined by three different alleles (A, B and i)
300
Define heterozygous alleles
A gene that has one dominant and one recessive allele
300
Brown eyes is dominant to blue eyes. Cross a blue eyed person with a homozygous dominant individual. List ALL possible genotypes.
100% Bb
300
In incomplete dominance how will the heterozygous offspring look (I.e. what will their phenotype be?)
Their phenotype will be a blend between the two parents
EX: Red + yellow flowers = orange
300
Dalmatians gene for fur color is controlled by codominance. Cross an all black Dalmatian with an all white Dalmatian.
What is the genotypic and phenotypic ratio?
Genotype: 100% BW
Phenotype: 100% spotted Dalmatians
300
Human skin color is determined by over 150 different genes. Skin color is an example of ___.
Polygenic inheritance.
400
Differentiate between homozygous dominant and homozygous recessive genes
AND
Provide examples of alleles
Homozygous dominant: the same dominant allele (EE)
Homozygous recessive: the same recessive allele (ee)
400
What is the genotypic ratio of the offpsring?
1:2:1
400
Red flowers are incompletely dominant to blue flowers. Cross a red flowering plant with a blue flowering plant.
What will be the genotype and phenotype?
Genotype: 100% RR'
Phenotype: 100% Purple flowers
400
Who is more susceptible to x-linked traits? Why?
Males because they only have one X chromosome and the Y chromosome can't mask over the inherited trait.
400
Define polygenic inheritance
A trait produced by two or more genes
500
Define gene
A section of DNA that makes a protein
500
DOUBLE JEOPARDY!
If Mom's genotype is AaBb, what would you write across the top of a Punnett square?
AB / Ab / aB / ab
500
In humans, curly hair (HH) is incompletely dominant to straight hair (H’H’). The heterozygous individual has wavy hair (HH’). Cross two people with wavy hair.
What will be the genotypic and phenotypic ratios?
Genotype= 1:2:1
Phenotype 1:2:1 (curly, wavy, straight)
500
What are X-linked traits?
Characteristics or conditions determined by genes located on the x chromosome.
500
Explain how epistasis works
One gene (the epistatic gene) masks, modifies, or suppresses the phenotypic expression of a different