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CSS 350 Midterm #2, 4/2/01
Name____________
PID_____________
6.
In corn three unlinked dominant genes are necessary for aleurone color.
The genotypes B-D-B- are colored. If any of these loci is homozygous
recessive the aleurone will be colorless. What is the expected
phenotypic frequency distribution (phenotypes and their frequencies) of
the F2 offspring of this F1 genotype: BbDdRR
7.
In the common daisy the genes A and a, B and b represent two pairs of
alleles acting on flower color. Only the A-B- genotypes have color.
Predict the genotype and phenotype of the F1 of a cross between two
colorless plants, one homozygous for the 'A' allele and the other
homozygous for the 'B' allele.
8.
Genes Q and R are 20 map units apart. What is the expected frequency
distribution of gametic genotypes (list all gametic genotypes and their
expected freqeuncies)of a plant with the genotype QR/qr?
In peas, tall (T) is dominant to short (t), red flowers (R) is dominant
to white flowers (r), and wide leaves (W) is dominant to narrow (w). A
tall, red, wide plant is crossed to a short, white, narrow plant and
the progeny are as follows:
tall red wide
400
tall white wide
99
short red wide
101
short white wide
400
1000
9.
What is the genotype (expressed to indicate the linkage arrangement,
i.e. _ _ _ / _ _ _ ) of the tall, red, wide parent plant used in the
testcross?
Page 1
CSS 350 Midterm #2, 4/2/01
Name____________
PID_____________
10.
Name one area of the world where the 'Green Revolution' took place.
11.
Cases where the relative phenotypic effects of alleles at one locus
depend on the genotype at one or more other loci are instances of:
A.
B.
C.
D.
E.
12.
_____________ are caused by changes in nucleotide sequences.
A.
B.
C.
D.
E.
13.
pleiotropy.
co-dominance.
incomplete dominance.
complete dominance.
penetrance and expressivity.
If two or more forms of the same gene exist, the different forms are
called:
A.
B.
C.
D.
E.
15.
phenotype
genotypes
mutations
traits
characters
When the same gene is related to flower color and stem color, it is an
example of :
A.
B.
C.
D.
E.
14.
epistasis.
epigenetics.
dominance.
co-dominance.
incomplete dominance.
incomplete dominance.
penetrance and expressivity.
pleiotrophic.
alleles.
dihybrid.
The stage of mitosis when chromosomes condense to form rod-shaped
structures visible under the microscope is called:
A.
B.
C.
D.
E.
interphase.
prophase.
metaphase.
anaphase.
telophase.
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CSS 350 Midterm #2, 4/2/01
16.
S phase
prophase I
metaphase I
anaphase I
prophase II
At which of the following stages of meiosis would homologous
chromosomes be paired?
A.
B.
C.
D.
E.
20.
G1
G2
mitotic prophase
mitotic metaphase
all of the above
Crossing over between homologous chromosomes occurs at which of the
following stages of meiosis?
A.
B.
C.
D.
E.
19.
interphase.
prophase.
metaphase.
anaphase.
telophase.
During which of the following stages of the cell cycle would a
chromosome consist of only a single chromatid?
A.
B.
C.
D.
E.
18.
PID_____________
The stage of mitosis when sister chromatids separate from each other
and migrate to opposite poles of a cell is called:
A.
B.
C.
D.
E.
17.
Name____________
prophase of meiosis I
prophase of meiosis II
metaphase of meiosis I
metaphase of meiosis II
a and c are correct
The chromosomal structure to which spindle fibers attach during the
mitotic divisions is referred to as a:
A.
B.
C.
D.
E.
chromatid.
centrosome.
kinetochore.
metaphase plate.
arm
Page 3
CSS 350 Midterm #2, 4/2/01
21.
Name____________
PID_____________
Mitosis results in _______ in chromosome number while meiosis results
in ______ chromosome number.
A.
B.
C.
D.
E.
a doubling of, no change in
no change in, no change in
a reduction by half in, no change in
no change in, a doubling of
no change in, a reduction by half in
Use the following information to answer questions 22-23.
Consider the 'R' and 'S' genes, where R is dominant to r, and S is
dominant to s. A testcross of a plant with genotype RrSs had the
following phenotypic frequency distribution:
R_S_
rrSR_ss
rrss
99
398
402
101
22.
What is the recombination frequency between these two genes?
23.
The 'R' and 'S' loci in the RrSs plant used in the testcross appear to
be:
A.
B.
C.
D.
E.
F.
24.
on the same chromosome in coupling (cis) phase
on the same chromosome in repulsion (trans) phase
unlinked
50 map units apart
epistatic
useless
Which of the following processes can generate recombinant gametes?
A.
B.
C.
D.
E.
Segregation of alleles in a heterozygote.
Crossing over between two linked heterozygous loci.
Independent assortment of two unlinked heterozygous loci.
b and c
a, b and c
T
F
25.
The first division that a plant zygote undergoes is mitosis.
T
F
26.
A cell with 40 chromatids at the beginning of mitosis has 20
chromosomes.
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CSS 350 Midterm #2, 4/2/01
Name____________
PID_____________
T
F
27.
In meiosis, one nucleus divides into four nuclei.
T
F
28.
Homologous chromosomes form pairs in Metaphase of mitosis.
T
F
29.
Discontinuous traits can be classified into distict categories of
phenotype.
T
F
30.
Many traits are influenced by both major genes with large effects, and
modifier genes with small effects.
T
F
31.
2N is shorthand for the number of chromosomes in a gamete.
T
F
32.
Two chromosomes are homologous because they are descendents of a common
progenitor chromosome.
T
F
33.
DNA replication must occur between Meiosis I and Meiosis II.
T
F
34.
The primary evidence of linkage between two genes is a preponderance of
parental gametes from a dihybrid.
T
F
35.
One cM = 1 map unit = 1% recombination frequency.
Page 5
Answer Key for Test "rw2.tst", 4/5/01
No. in No. on
Q-Bank Test Correct Answer
2 23
6
Phenotype: 9 Color; 7 Colorless
2
27
7
4
4
4
2
2
2
2
3
3
3
3
3
3
3
4
4
4
3
3
3
3
4
4
4
4
4
4
4
84
60
93
1
13
14
8
2
3
4
9
14
19
21
81
82
19
81
82
83
84
86
87
88
89
90
91
92
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
Genotype
Phenotype
AaBb
Colored
QR 40%, qr 40%, Qr 20%, qR 20%
TRW/trW
Indian subcontinent or its countries, Mexico, others?
A
C
A
D
B
D
A
B
E
C
E
20%
B
D
T
T
T
F
T
T
?
T
F
T
T
Page 1
Statistics for Test "rw2.tst". Total questions: 30
Key Word
None
Total Difficulty Level
30 None
1
2
3
4
Total
15
9
4
1
1
None
Free Format
True or False
Multiple Choice
Matching
Total
6
11
13
0