1. In pea plants a tall allele (T) is dominant over a short allele (t).
Which punnet square depicts a 1:1 ratio of tall plants to short plants?
A.
X
t
t
T
Tt
Tt
T
Tt
Tt
B.
X
t
t
T
Tt
Tt
t
tt
tt
C.
X
T
t
T
TT
Tt
t
Tt
tt
D.
X
T
t
T
TT
Tt
T
TT
Tt
18 Observe the following diagram.
Identify where genetic variation can occur.
A.
B.
C.
D.
A and B
B and C
A and C
A, B and C
3. Two species of endangered orchid, Orchidus viotletus and Orchidus aquas are at risk
of being completely eliminated due to housing development.
Data was collected examining the gene for flower colour in Orchidus aquas. The blue
flower allele is dominant to a white flower allele. The number of each genotype in the
population of 24 individuals is shown below:
(a)
Genotype
Number of individuals
BB
16
Bb
5
bb
3
Construct a punnet square to show a cross between heterozygotes.
2
3
(b)
Use the information above to calculate allele frequency in the Orchidus
aquas population. Show all your working.
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