a.
Completely dominant
b.
Codominant
c.
Overdominant
d.
Incompletely dominant
|
Problems In Dominance for Autosomal Traits |
For the following autosomal traits, determine from the phenotypes of
the F1
progeny whether the trait is c completely dominant (completely recessive),
incompletely dominant, codominant or overdominant. Since these traits are
known to be autosomal, the reciprocal F1 crosses have not been done.
(Most of the organisms displayed are fictional).
Click on the green ball to choose your answer.
| 1. |
In the T-Wrex species of cyberbots, there are
two pure-breeding strains. One strain has
light pink body color and the other strain has dark pink body color.
F1 progeny between these two strain have deep, deep, blood-red
body color. Based on the available
information, the inheritance of body color in T-Wrex is most likely: |
|
a. |
Completely dominant |
|
|
b. |
Codominant |
|
|
c. |
Overdominant |
|
|
d. |
Incompletely dominant |
|
| 2. |
On the Planet Crayte, Dragons have valuable
gizzard stones (Crayte Pearls). Normal dragons have only 10 pearls.
Dragons homozygous for the autosomal
trait Jackpot produce 30 pearls. A pure-breeding Jackpot male is mated to a
pure-breeding normal female. All
of their progeny have 25 pearls. Pearl number is most likely inherited as: |
|
a. |
Completely dominant |
|
|
b. |
Codominant |
|
|
c. |
Overdominant |
|
|
d. |
Incompletely dominant |
|
| 3.. |
Frisbee turtles from a pure-breeding Pennsylvania colony
have
diamond marking on their shells. Frisbee turtles from a pure-breeding New Jersey colony
have circles on
their shells. The F1 progeny have both circles and diamonds.
The most likely mode of inheritance is: |
|
a. |
Completely dominant |
|
|
b. |
Codominant |
|
|
c. |
Overdominant |
|
|
d. |
Incompletely dominant |
|
| 4. |
A breeder has a pure-breeding colony of New
Jersey Rumbunnies with dark coat color and another
pure-breeding colony of rumbunnies with white hair (albino). The F1 progeny
all have dark coat color. The most likely mode of inheritance of dark coat color is: |
|
a. |
Completely dominant |
|
|
b. |
Codominant |
|
|
c. |
Overdominant |
|
|
d. |
Incompletely dominant |
|
| 5. |
Another breeder has a pure-breeding
colony of New Jersey Rumbunnies with short hair and a second pure-breeding colony
of rumbunnies with long hair. The F1 progeny all have long
hair. The most likely mode of inheritance
of long hair length is: |
|
a. |
Completely dominant |
|
|
b. |
Codominant |
|
|
c. |
Overdominant |
|
|
d. |
Incompletely dominant |
|
| 6. |
Elves are allergic to iron.
Werewolves are allergic to silver. Metal allergy
is a single gene trait. The F1 progeny of a cross between
elves and werewolves are allergic to both iron and silver.
The most likely mode of inheritance for metal
allergy is: |
|
a. |
Completely dominant |
|
|
b. |
Codominant |
|
|
c. |
Overdominant |
|
|
d. |
Incompletely dominant |
|
| 7. |
Dust bunnies normally have five toes.
Pure-breeding polydactly bunnies have eight toes. The F1 progeny of
a cross between a pure-breeding five-toed and a pure-breeding eight-toed dust bunny
has six toes. The most likely mode of inheritance for toe number is: |
|
a. |
Completely dominant |
|
|
b. |
Codominant |
|
|
c. |
Overdominant |
|
|
d. |
Incompletely dominant |
|
| 8. |
Eye color in Sleens is normally either gray-black or black-gray (a single gene system
- basically the eyes look almost alike). When a scientist crosses a pure-breeding black-gray Sleen and a pure-breeding
gray-black Sleen, the F1 progeny are deep, ebony black ("Deep space black").
Based on the available information the inheritance of eye
color in Sleen is probably: |
|
a. |
Completely dominant |
|
|
b. |
Codominant |
|
|
c. |
Overdominant |
|
|
d. |
Incompletely dominant |
|