1. The following diagram shows the inheritance of tongue rolling in a family.
a) How many children do Tony and Janice have? (1)
b) What is the phenotype of Andrew? (1)
c) Which characteristic is dominant ? (1)
d) Mark with a letter H all the individuals who are definitely homozygous (1)
e) Is Janice homozygous or heterozygous for this trait?
Give a reason for your answer.
Answer____________________________________________________
Reason____________________________________________________ (2)
- Study the diagram of inheritance of coat colour in leopards and answer the questions which follow.
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State whether the following statements are true or false.
- Both parents are homozygous for this trait
- Both parents are heterozygous for this trait
- One parent is homozygous for this trait
(1)
b) If the letter S is being used for ‘spotted’ fur, what is the genotype of the parents?
Parent 1______________________ Parent 2____________________ (1)
c) Which coat colour is recessive? (1)
d) Mark on the diagram the F1 generation (1)
e) What term is used to describe two forms of the same gene? (1)
3. In an experiment designed to predict the results of many crosses, 10 pupils each tossed two coins at random 8 times each. A “head” stood for H and a “tail” for h. Their results are shown in the table.
a) How many homozygous results were there in total?
___________________________________________ (1)
b) Calculate the number of ‘off-spring’ which would have the dominant and recessive features.
Dominant ___________________ Recessive __________________ (1)
c) What percentage of the predicted ‘offspring’ are heterozygous?
_____________________________________________________ (1)
- People today tend to be bigger than their parents and grandparents were, yet they have inherited their ancestors’ genes. What other factor has an effect on phenotype?
____________________________________________________________ (1)
