In intensive aquaculture, fish farmers aim to produce all-female populations of rainbow trout (Oncorhynchus mykiss) because females grow faster and do not exhibit early sexual maturation, which reduces meat quality. To achieve this, farmers fertilise normal female eggs using sperm obtained from sex-reversed 'masculinised' female trout (which have female XX genotypes but male phenotypes).
In one breeding trial, 850 fertilised eggs survived to the fry stage, of which 831 were confirmed to be female. Calculate the success of producing female trout as a percentage of the total surviving population. Give your answer to 1 decimal place.
Describe the control group that should be used in this investigation to compare against the group fertilised using masculinised female sperm.
Predict the expected percentage of female offspring in this control group.
74 exam-style questions on Edexcel IGCSE Biology Food production. Each one has a worked solution and a mark scheme showing where the marks go.