How many of their daughters might be expected to be color-blind
dwarfs?
A) all
B) none
C) half
D) one out of
four
E) three out of four
none
What proportion of their sons would be color-blind and of normal
height?
A) none
B) half
C) one out of four
D)
three out of four
E) all
half
They have a daughter who is a dwarf with normal color vision. What is
the probability that
she is heterozygous for both genes?
A)
0%
B) 25%
C) 50%
D) 75%
E) 100%
100%
Between which two genes would you expect the highest frequency of
recombination?
A) A and W
B) W and E
C) E and G
D)
A and E
E) A and G
A and G
In a series of mapping experiments, the recombination frequencies for
four different linked
genes of Drosophila were determined as
shown in Figure 12.2. What is the order of these genes
on a
chromosome map?
A) rb-cn-vg-b
B) vg-b-rb-cn
C)
cn-rb-b-vg
D) b-rb-cn-vg
E) vg-cn-b-rb
b-rb-cn-vg
A plantlike organism on the planet Pandora can have three recessive
genetic traits: bluish leaves,
due to an allele (a) of gene A; a
feathered stem, due to an allele (b) of gene B; and hollow
roots
due to an allele (c) of gene C. The three genes are linked
and recombine as follows:
A geneticist did a testcross with an
organism that had been found to be heterozygous for the
three
recessive traits and she was able to identify progeny of the following
phenotypic
distribution (+ = wild type):
Which of the following are the phenotypes of the parents in this
cross?
A) 2 and 5
B) 1 and 6
C) 4 and 8
D) 3 and
7
E) 1 and 2
4 and 8
In which progeny phenotypes has there been recombination between
genes A and B?
A) 1, 2, 5, and 6
B) 1, 3, 6, and 7
C)
2, 4, 5, and 8
D) 2, 3, 5, and 7
E) in all 8 of them
1, 2, 5, and 6
If recombination frequency is equal to distance in map units, what is
the approximate distance
between genes A and B?
A) 1.5 map
units
B) 3 map units
C) 6 map units
D) 15 map
units
E) 30 map units
3 map units
What is the greatest benefit of having used a testcross for this
experiment?
A) The homozygous recessive parents are obvious to
the naked eye.
B) The homozygous parents are the only ones whose
crossovers make a difference.
C) Progeny can be scored by their
phenotypes alone.
D) All of the progeny will be
heterozygous.
E) The homozygous recessive parents will be unable
to cross over.
Progeny can be scored by their phenotypes alone.
The greatest distance among the three genes is between a and c. What
does this mean?
A) Gene c is between a and b.
B) Genes are
in the order: a–b–c.
C) Gene a is not recombining with c.
D)
Gene a is between b and c.
E) Distance a–b is equal to distance a–c.
Genes are in the order: a–b–c.