Question

2. Hostas are a decorative leafy shade-loving plant. You take pollen from a true-breeding variety called "Fire and Ice" with leaves that start white then develop green sectors, and purple flowers. The second strain (the female parent) is a true breeding variety called Earth Angel, which has green leaves with golden/yellow leaf centers, and white flowers. "Fire and Ice" "Earth Angel" The F1s all have the golden centered green leaves and pink flowers. Flower colors The F2s come out as follows 59 golden centered leaves with pink flowers 31 golden centered leaves with purple flowers 30 golden centered leaves with white flowers When you do the reciprocal cross with the female parent being Fire and Ice, and the male the original Earth Angel your Fls are all have the Fire and Ice leaves with pink flowers. a) What is the most likely way that these genes are inheriting? Leaf color Flower color b) What would you expect the F2 offspring of the reciprocal cross to be in phenotype and proportion?

Answer 1

1) here all plants have gold centred leaves like their mother plant so the inheritance of the leave colour is mitochondrial, mitochondria is provided by the mother so all the progenies have the same phenotype as that of the mother.

parent plants are purple and white but F1 is all pink and in the F2

Purple: pink: white= 31:59:30 this is almost equal to 1:2:1, which is the expected ratio of incomplete dominance

so the inheritance of flower colour is incomplete dominance, purple is incompletely dominant to white so heterozygotes are pink so the answer is

a) leaf colour- maternal inheritance, flower colour- incomplete dominance.

b) reciprocal cross means

the mother plant is fire and Ice and father is Earth angel

so the leaf colour depends on the mother so all F1s will be white centred leaves and pink flowers

and in the F2 also all plants have white centred leaves and the flower colour will be observed Red:pink:white= 1:2:1

so expected ratio is

white centred leaves and Red flowers : white centred leaves and pink flowers : white centred leaves and white flowers= 1:2:1