Corn typically produces male flowers at the top of the plant and female flowers along the side of the plant. A corn vari
Posted: Mon May 23, 2022 7:09 am
Corn typically produces male flowers at the top of the plant and
female flowers along the side of the plant. A corn variant was
identified in which almost all plants were male-sterile
(did not produce pollen, but female flowers were produced
normally); within these variants, a few were male-fertile but
produced very little pollen.
i) If normal male pollen (male-fertile) is used to fertilize
female flowers on the male-sterile plants, the F1
individuals are all male-sterile in phenotype. Explain how this
result could or could not be the result of maternal-effect
inheritance. Then explain how this result could or could not be the
result of cytoplasmic inheritance.
ii) When normal male pollen is used to fertilize female flowers
of the F1 plants, the F2 generation is also all male-sterile in
phenotype. Now explain how this result could or could not be the
result of maternal-effect inheritance. Explain how this result
could or could not be the result of cytoplasmic inheritance.
iii) When normal female plants are fertilized with the rare
pollen produced by the male-sterile variant, all of the F1
individuals are male-fertile with normal amounts of pollen. When
self-fertilized, these plants breed true as normal male-fertile
plants with normal amounts of pollen. How are these results
consistent or inconsistent with the maternal-effect and cytoplasmic
inheritance models you developed in parts (i) and (ii)?
female flowers along the side of the plant. A corn variant was
identified in which almost all plants were male-sterile
(did not produce pollen, but female flowers were produced
normally); within these variants, a few were male-fertile but
produced very little pollen.
i) If normal male pollen (male-fertile) is used to fertilize
female flowers on the male-sterile plants, the F1
individuals are all male-sterile in phenotype. Explain how this
result could or could not be the result of maternal-effect
inheritance. Then explain how this result could or could not be the
result of cytoplasmic inheritance.
ii) When normal male pollen is used to fertilize female flowers
of the F1 plants, the F2 generation is also all male-sterile in
phenotype. Now explain how this result could or could not be the
result of maternal-effect inheritance. Explain how this result
could or could not be the result of cytoplasmic inheritance.
iii) When normal female plants are fertilized with the rare
pollen produced by the male-sterile variant, all of the F1
individuals are male-fertile with normal amounts of pollen. When
self-fertilized, these plants breed true as normal male-fertile
plants with normal amounts of pollen. How are these results
consistent or inconsistent with the maternal-effect and cytoplasmic
inheritance models you developed in parts (i) and (ii)?