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4.25 Probabilities from monohybrid crosses
Exam question
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Two heterozygous parents (Tt × Tt) have a child. Calculate the probability, as a percentage, that the child is homozygous recessive.
(2)Total for this question: 2 marks
4.25 Probabilities from monohybrid crosses
Exam question
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A parent Gg and a parent gg have a child. Calculate the probability that the child shows the recessive phenotype.
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Total for this question: 2 marks
4.25 Probabilities from monohybrid crosses
Exam question
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What is the chance that a child of Aa × Aa is a carrier?
(1)Total for this question: 1 mark
4.25 Probabilities from monohybrid crosses
Exam question
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Explain why every child of two carrier parents has the same chance of inheriting a condition.
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Total for this question: 2 marks
4.25 Probabilities from monohybrid crosses
Exam question
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Two Tt plants produce 480 seeds. Calculate how many seeds would be expected to grow into short (tt) plants.
(2)Total for this question: 2 marks
4.25 Probabilities from monohybrid crosses
Exam question
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A cross is expected to give a 1 : 1 ratio. 56 offspring are produced. Calculate the expected number of each phenotype.
(2)Total for this question: 2 marks
4.25 Probabilities from monohybrid crosses
Exam question
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Calculate the probability that two carrier parents have a child who is not affected.
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Total for this question: 2 marks
4.25 Probabilities from monohybrid crosses
Exam question
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Explain why the ratio 3 : 1 is a probability, not a certainty.
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Total for this question: 2 marks
4.25 Probabilities from monohybrid crosses
Exam question
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Out of 200 offspring of Bb × Bb, 140 have the dominant phenotype. Calculate the percentage difference between the observed and expected number of dominant offspring.
(2)Total for this question: 2 marks
4.25 Probabilities from monohybrid crosses
Exam question
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Calculate the probability that a couple Hh × hh has two children who are both hh.
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Total for this question: 2 marks
4.25 Probabilities from monohybrid crosses
Exam question
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Explain why a carrier mother and an unaffected non-carrier father cannot have an affected child for a recessive condition.
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Total for this question: 2 marks
4.25 Probabilities from monohybrid crosses
Exam question
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What fraction of offspring from AA × aa are heterozygous?
(1)Total for this question: 1 mark
4.25 Probabilities from monohybrid crosses
Exam question
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Suggest why scientists use large numbers of offspring in breeding experiments.
(2)Write your answer, then press Show model answer and tick each mark point your answer makes. Your answer is not saved.
Total for this question: 2 marks
