Bio 202 EXAM 3 QUESTIONS AND ANSWERS
VERIFIED 100% CORRECT A+ GRADED
A dihybrid was test-crossed.
400 progeny were counted.
How many would we expect in each phenotypic category? - ANSWER
100:100:100:100
A dihybrid test-cross was performed followed by a chi-square analysis. The
p value was less than 0.05. What does this mean? It is likely that... -
ANSWER The two genes are not independently assorting.
Autosomal Recessive - ANSWER *look for children with
unaffected parents
1. skips generations
2. males and females equally affected
3. rare
Autosomal Dominnt - ANSWER *MUST have affected parent
1. does NOT skip generations
X-linked recessive - ANSWER 1. affects more males
2. skips generation
3. never have father to son transmisson
4. unaffacted individuals have affected children
x-linked dominant - ANSWER 1. males and females affected
2. no father to son transmission
3. an affected male passes to all his daughters
A sex-linked recessive allele produces a red-green colorblindness in
humans. A normal woman named Kate whose father was color-blind
marries a color blind man named William. Of the girls produced from this
couple, what proportion can be expected to be colorblind? - ANSWER 1/2
of the girls
, 2 hetero: incomplete dominance - ANSWER 1:2:1 phenotypic
ratio
2 hetero: complete dominance - ANSWER 3:1 pheno ratio
2 hetero: co-dominance - ANSWER 1:2:1 pheno ratio
Polymorphic - ANSWER "many forms" (two or more common
wildtypes alleles in a population)
*blood type
Human leukocyte antigen (HLA) - ANSWER used to math bone
marrow donor 0 it is a protein or marker found on body cells
monomorphic - ANSWER When all individuals in a population are
identical with regard to a particular trait
All wild type or mutant
Pleiotrophic - ANSWER an allele that affects several properties
of an organism
Penetrance - ANSWER number of individuals with a particular
genotype that demonstrate the expected phenotype.
i.e. 100% means complete penetrance
Four people, clearly have the dominant allele, yet only 3 have the
phenotype. - ANSWER 75% penetrance
variable expressivity
slide 24 - ANSWER range of expression of a given phenotype
(the degree or intensity)
VERIFIED 100% CORRECT A+ GRADED
A dihybrid was test-crossed.
400 progeny were counted.
How many would we expect in each phenotypic category? - ANSWER
100:100:100:100
A dihybrid test-cross was performed followed by a chi-square analysis. The
p value was less than 0.05. What does this mean? It is likely that... -
ANSWER The two genes are not independently assorting.
Autosomal Recessive - ANSWER *look for children with
unaffected parents
1. skips generations
2. males and females equally affected
3. rare
Autosomal Dominnt - ANSWER *MUST have affected parent
1. does NOT skip generations
X-linked recessive - ANSWER 1. affects more males
2. skips generation
3. never have father to son transmisson
4. unaffacted individuals have affected children
x-linked dominant - ANSWER 1. males and females affected
2. no father to son transmission
3. an affected male passes to all his daughters
A sex-linked recessive allele produces a red-green colorblindness in
humans. A normal woman named Kate whose father was color-blind
marries a color blind man named William. Of the girls produced from this
couple, what proportion can be expected to be colorblind? - ANSWER 1/2
of the girls
, 2 hetero: incomplete dominance - ANSWER 1:2:1 phenotypic
ratio
2 hetero: complete dominance - ANSWER 3:1 pheno ratio
2 hetero: co-dominance - ANSWER 1:2:1 pheno ratio
Polymorphic - ANSWER "many forms" (two or more common
wildtypes alleles in a population)
*blood type
Human leukocyte antigen (HLA) - ANSWER used to math bone
marrow donor 0 it is a protein or marker found on body cells
monomorphic - ANSWER When all individuals in a population are
identical with regard to a particular trait
All wild type or mutant
Pleiotrophic - ANSWER an allele that affects several properties
of an organism
Penetrance - ANSWER number of individuals with a particular
genotype that demonstrate the expected phenotype.
i.e. 100% means complete penetrance
Four people, clearly have the dominant allele, yet only 3 have the
phenotype. - ANSWER 75% penetrance
variable expressivity
slide 24 - ANSWER range of expression of a given phenotype
(the degree or intensity)
