A poor but ambitious graduate student has discovered a goldfish with blue scales

Question

A poor but ambitious graduate student has discovered a goldfish with blue scales, a very unusual color in this species. Envisioning a lucrative possibility for the aquarium fish trade, she hoped to produce a pure-breeding blue-scaled goldfish. She crossed blue and normal individuals in every different combination, with the outcomes that appear below. In no case was she able to produce the pure-breeding blue line she sought.

Cross type Combined results of large litters from multiple matings normal x normal (12 crosses): 497 normal : 0 blue

normal x blue (14 crosses): 248 normal : 236 blue (all litters contained some normal and some blue individuals)

blue x blue (13 crosses): 131 normal : 255 blue (all litters contained some normal and some blue individuals, but no litters were 100% blue)

Suggest a simple and reasonable genetic hypothesis to explain the inheritance of the blue-scale characteristic and briefly explain your answer.

Explanation / Answer

Extra genetical factors influence the trait that encodes color of scales. These factors called epigenetics. The color encoding trait overlap on normal genes and exhibit incomplete dominance.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.