Page 43 - CB1.3 Genetic Varation sciPAD

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© Silverback Academic Media 43
CB 1.3 GENETIC VARIATION
TRACKING GENES
Tracking Genes for Health - Polydactylism
Polydactylism is a genetic disorder that results in a person being born
with extra fingers or toes. It occurs in approximately 1 in every 500 live
births in New Zealand.
The pedigree chart below shows the inheritance of polydactylism
through three generations of one family.
Normal Female
Normal Male
Affected Female
Affected Male
KEY
Mark
Eva
Paul
Tanya Sue Michelle Harry
John
Adam
Rachel James Mindy
I
II
III
Odette
Using evidence from the pedigree chart, determine the genotype of Odette. In your
answer you must:
•
explain whether the polydactylism allele is ‘dominant’ or ‘recessive’.
•
refer to specific individuals from the pedigree chart.
•
support your answer with Punnett squares.




















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