BIOD 331/ BIOD331 Final Exam: (NEW
2025/ 2026 Update) Pathophysiology |
Questions & Answers| Grade A| 100%
Correct (Verified Solutions)- Portage
Learning.
What kind of dominance is this:
aa-0, Aa- 0<x<1, AA-2?
partial dominance, but since heterozygote is between the values of 0 and 1, it's
closer to the phenotype "aa"
What is overdominance?
phenotype of heterozygote is greater than both homozygotes
What is under dominance?
Phenotype of heterozygotes is smaller than homozygotes
What is our additive value (a)?
the distance between either homozygote phenotype value and the midpoint
Does the sign of the additive value matter?
No
What is dominance effect (d)?
,it's the distance between the phenotypic value of the heterozygote and the
midpoint (0)
Does the sign of "d" matter?
yes
"aa" has the average phenotype of 10, "Aa" has the average phenotype of 18,
and "AA" has the average phenotype of 20. What is the zero point (midpoint)?
What are the values of "a" and "d"?
midpoint: 15
a: 15-10= 5
d: 18-15= +3
For a one locus, two-allele system with p (frequency of A) = 0.25 and q
(frequency of a) = 0.75 and the following phenotypic values for a bristle trait: AA
= 23 bristles, Aa = 20 bristles, and aa = 9 bristles, calculate the additive effect (a)
and the dominance effect (d).
a: 16-7=7
d: 20-16= +4
What is the equation for the equilibrium phenotypic mean (P bar)?
G bar = P bar = a(p-q)+2pqd
For a one locus, two-allele system with p (frequency of A) = 0.25 and q
(frequency of a) = 0.75 and the following phenotypic values for a bristle trait: AA
= 23 bristles, Aa = 20 bristles, and aa = 9 bristles. a = 7 and d = +4, calculate the
equilibrium phenotypic mean (P bar)
P bar = 9(0.25-0.75) + 2(0.25)(0.75)(4) = -2 --> 16 + (-2) = 14 (REMEMBER, the
value must be added to the midpoint to get P bar)
Vp = Vg + Ve
Vp is phenotypic variance. As shown above, there are two types of variance
underlying the overall phenotypic variance. What is Vg and Ve?
, - Vg (genetic variance) is the variance due to genetic factors
- Ve (environmental factors) is the variance due to environmental factors
The genetic variance (Vg) includes all types of genetic differences among
individuals. There are three basic types of variance included within the overall
genetic variance --> Vg = Va + Vd + Vi. What are these components?
- Va = additive genetic variance
- Vd = dominance variance
- Vi = interaction or epistatic variance
Additive genetic variance (Va) is the most important component of genetic
variance in ______ reproducing species in determining change in phenotypic
mean from generation to generation
sexually
In regards to Va, if the other components of genetic variance, Vd and Vi, are 0,
and Ve is the same in parental and offspring generations, or in other words if
there's no dominance or interaction and then environment is consistent
between generations, then....
average trait value in offspring = average of the parents
Va = 2pq[a + d(q − p)]²
If there’s no dominance (meaning the heterozygote is exactly in between the
two homozygotes), the formula gets simpler: Va = 2pq·a².
If d = 0, at what values of p and q is the additive genetic variance maximized?
a. p = 0, q = 1
b. p = 1, q = 0
c. p = 0.5, q = 0.5
d. p = 0.25, q = 0.75
2025/ 2026 Update) Pathophysiology |
Questions & Answers| Grade A| 100%
Correct (Verified Solutions)- Portage
Learning.
What kind of dominance is this:
aa-0, Aa- 0<x<1, AA-2?
partial dominance, but since heterozygote is between the values of 0 and 1, it's
closer to the phenotype "aa"
What is overdominance?
phenotype of heterozygote is greater than both homozygotes
What is under dominance?
Phenotype of heterozygotes is smaller than homozygotes
What is our additive value (a)?
the distance between either homozygote phenotype value and the midpoint
Does the sign of the additive value matter?
No
What is dominance effect (d)?
,it's the distance between the phenotypic value of the heterozygote and the
midpoint (0)
Does the sign of "d" matter?
yes
"aa" has the average phenotype of 10, "Aa" has the average phenotype of 18,
and "AA" has the average phenotype of 20. What is the zero point (midpoint)?
What are the values of "a" and "d"?
midpoint: 15
a: 15-10= 5
d: 18-15= +3
For a one locus, two-allele system with p (frequency of A) = 0.25 and q
(frequency of a) = 0.75 and the following phenotypic values for a bristle trait: AA
= 23 bristles, Aa = 20 bristles, and aa = 9 bristles, calculate the additive effect (a)
and the dominance effect (d).
a: 16-7=7
d: 20-16= +4
What is the equation for the equilibrium phenotypic mean (P bar)?
G bar = P bar = a(p-q)+2pqd
For a one locus, two-allele system with p (frequency of A) = 0.25 and q
(frequency of a) = 0.75 and the following phenotypic values for a bristle trait: AA
= 23 bristles, Aa = 20 bristles, and aa = 9 bristles. a = 7 and d = +4, calculate the
equilibrium phenotypic mean (P bar)
P bar = 9(0.25-0.75) + 2(0.25)(0.75)(4) = -2 --> 16 + (-2) = 14 (REMEMBER, the
value must be added to the midpoint to get P bar)
Vp = Vg + Ve
Vp is phenotypic variance. As shown above, there are two types of variance
underlying the overall phenotypic variance. What is Vg and Ve?
, - Vg (genetic variance) is the variance due to genetic factors
- Ve (environmental factors) is the variance due to environmental factors
The genetic variance (Vg) includes all types of genetic differences among
individuals. There are three basic types of variance included within the overall
genetic variance --> Vg = Va + Vd + Vi. What are these components?
- Va = additive genetic variance
- Vd = dominance variance
- Vi = interaction or epistatic variance
Additive genetic variance (Va) is the most important component of genetic
variance in ______ reproducing species in determining change in phenotypic
mean from generation to generation
sexually
In regards to Va, if the other components of genetic variance, Vd and Vi, are 0,
and Ve is the same in parental and offspring generations, or in other words if
there's no dominance or interaction and then environment is consistent
between generations, then....
average trait value in offspring = average of the parents
Va = 2pq[a + d(q − p)]²
If there’s no dominance (meaning the heterozygote is exactly in between the
two homozygotes), the formula gets simpler: Va = 2pq·a².
If d = 0, at what values of p and q is the additive genetic variance maximized?
a. p = 0, q = 1
b. p = 1, q = 0
c. p = 0.5, q = 0.5
d. p = 0.25, q = 0.75
