Question 1

Chiasmata are structures of cross over between non-sister chromatids of homologous chromosomes.

Accepted Answer

A) True 
 B)False

Question 2

In an individual with genotype Lpq/lPQ the L gene is in the middle.What would be the genotypes of the gametes produced by a double crossover surrounding the L locus?

Accepted Answer

A)  LPQ and lpq 
B)  LpQ and lPq 
C)  lpQ and LPq 
D)  Lpq and lPQ 
E)  cannot be determined 
A)  LPQ and lpq 
B)  LpQ and lPq 
C)  lpQ and LPq 
D)  Lpq and lPQ 
E)  cannot be determined

Question 3

Some of the larger human chromosomes typically contain multiple chiasmata during meiotic prophase.If you were to carefully study the distribution of these chiasmata,what would you find?

Accepted Answer

A)  Chiasmata are randomly distributed along chromosomes. 
B)  All chromosome pairs have the same number of chiasmata. 
C)  A single chromosome pair always has the same number of chiasmata in every meiotic cell. 
D)  Chiasmata are spaced along a chromosome arm more regularly than would be expected by chance. 
E)  Chiasmata are spaced more irregularly along a chromosome arm than would be expected by chance. 
A)  Chiasmata are randomly distributed along chromosomes. 
B)  All chromosome pairs have the same number of chiasmata. 
C)  A single chromosome pair always has the same number of chiasmata in every meiotic cell. 
D)  Chiasmata are spaced along a chromosome arm more regularly than would be expected by chance. 
E)  Chiasmata are spaced more irregularly along a chromosome arm than would be expected by chance.

Question 4

When mapping three genes,why do geneticists prefer to do one three-point cross rather than three two-point crosses? Give two reasons.

Accepted Answer

1.Three-point crosses can establish gene

Question 5

Which of the following processes can generate recombinant gametes?

Accepted Answer

A)  Segregation of alleles in a heterozygote. 
B)  Crossing over between two linked heterozygous loci. 
C)  Independent assortment of two unlinked heterozygous loci. 
D)  Crossing over between two linked heterozygous loci and independent assortment of two unlinked heterozygous loci. 
E)  Segregation of alleles in a heterozygote,crossing over between two linked heterozygous loci and independent assortment of two unlinked heterozygous loci. 
A)  Segregation of alleles in a heterozygote. 
B)  Crossing over between two linked heterozygous loci. 
C)  Independent assortment of two unlinked heterozygous loci. 
D)  Crossing over between two linked heterozygous loci and independent assortment of two unlinked heterozygous loci. 
E)  Segregation of alleles in a heterozygote,crossing over between two linked heterozygous loci and independent assortment of two unlinked heterozygous loci.

Question 6

How does Mendel's law of independent assortment relate to the concept of linkage?

Accepted Answer

Mendel's law of independent as

Question 7

The map of a chromosome interval is Q-10 m.u.-R-40 m.u.-S.Which interval would likely show the higher ratio of double to single chiasmata?

Accepted Answer

A)  Q-R 
B)  R-S 
C)  The ratios would be the same in the two intervals. 
D)  Two chiasmata never occur in the same interval. 
A)  Q-R 
B)  R-S 
C)  The ratios would be the same in the two intervals. 
D)  Two chiasmata never occur in the same interval.

Question 8

Genetic mapping distance calculated for a chromosome is directly related to physical distance along that chromosome.

Accepted Answer

A) True 
 B)False

Question 9

What are chiasmata?

Accepted Answer

The cytological mani

Question 10

Individuals heterozygous for the RB+ and RB- alleles can develop tumours as a result of

Accepted Answer

A)  a mitotic crossover that leads to homozygosity for both RB+ and RB-. 
B)  a somatic mutation in the RB+ allele that leads to homozygosity for RB-. 
C)  a somatic mutation in the RB- allele that leads to homozygosity for RB+. 
D)  the fact that RB- is dominant to RB+. 
E)  either a mitotic crossover that leads to homozygosity for both RB- or a somatic mutation in the RB+ allele that leads to homozygosity for RB-. 
A)  a mitotic crossover that leads to homozygosity for both RB+ and RB-. 
B)  a somatic mutation in the RB+ allele that leads to homozygosity for RB-. 
C)  a somatic mutation in the RB- allele that leads to homozygosity for RB+. 
D)  the fact that RB- is dominant to RB+. 
E)  either a mitotic crossover that leads to homozygosity for both RB- or a somatic mutation in the RB+ allele that leads to homozygosity for RB-.

Question 11

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 leaves (w).A tall,red,wide-leaved plant is crossed to a short,white,narrow-leaved plant and the progeny are as follows:$$\begin{array} { | l | c | } 
\hline \text { tall red wide } & 381 \
\hline \text { tall white wide } & 122 \
\hline \text { short red wide } & 118 \
\hline \text { short white wide } & 379 \
\hline & 1000 \
\hline
\end{array}$$ 
What is the genotype of the tall,red,wide-leaved parent?

Accepted Answer

The answer of In peas,tall (T)is dominant to short (t),red...

Question 12

The measured distance between genes D and E in a two-point test cross is 50 map units.What does this mean in physical terms?

Accepted Answer

A)  D and E are on different pairs of chromosomes. 
B)  D and E are linked and exactly 50 map units apart. 
C)  D and E are linked and at least 50 map units apart. 
D)  either D and E are on different pairs of chromosomes or D and E are linked and exactly 50 map units apart. 
E)  either D and E are on different pairs of chromosomes or D and E are linked and at least 50 map units apart. 
A)  D and E are on different pairs of chromosomes. 
B)  D and E are linked and exactly 50 map units apart. 
C)  D and E are linked and at least 50 map units apart. 
D)  either D and E are on different pairs of chromosomes or D and E are linked and exactly 50 map units apart. 
E)  either D and E are on different pairs of chromosomes or D and E are linked and at least 50 map units apart.

Question 13

Recombination due to crossing over occurs only rarely in mitosis.

Accepted Answer

A) True 
 B)False

Question 14

The R/r and S/s genes are linked and 10 map units apart.In the cross Rs/rS × rs/rs what fraction of the progeny will be RS/rs?

Accepted Answer

A)  5% 
B)  10% 
C)  25% 
D)  40% 
E)  45% 
A)  5% 
B)  10% 
C)  25% 
D)  40% 
E)  45%

Question 15

The zipper-like connection between paired homologs in early prophase is known as a

Accepted Answer

A)  spindle fiber. 
B)  synaptic junction. 
C)  synaptonemal complex. 
D)  chiasma. 
E)  none of the choices are correct. 
A)  spindle fiber. 
B)  synaptic junction. 
C)  synaptonemal complex. 
D)  chiasma. 
E)  none of the choices are correct.

Question 16

In Drosophila,the genes y,f,and v are all X-linked.y f v females are crossed to wild-type males and the F1 females are test-crossed.The F2 are distributed as follows.$$\begin{array} { | l | r | } 
\hline y f v & 3210 \
\hline y f + & 72 \
\hline y + v & 1024 \
\hline y + + & 678 \
\hline + f v & 690 \
\hline + f + & 1044 \
\hline + + v & 60 \
\hline + + + & \underline { 3222 } \
\hline & 10,000 \
\hline
\end{array}$$ 
State what a coefficient of coincidence of 0.5 would mean.

Accepted Answer

Half as many double crossover

Question 17

In Drosophila,the genes y (yellow body)and car (carnation eyes)are located at opposite ends of the X chromosome.In doubly heterozygous females (y+ car+/y car),a single chiasma is observed somewhere along the X chromosome in 90% of the examined oocytes.No X chromosomes with multiple chiasmata are observed.What percentage of the male progeny from such a female would be recombinant for y and car?

Accepted Answer

A)  5% 
B)  10% 
C)  45% 
D)  55% 
E)  90% 
A)  5% 
B)  10% 
C)  45% 
D)  55% 
E)  90%

Question 18

If the map distance between genes A and B is 10 map units and the map distance between genes B and C is 25 map units,what is the map distance between genes A and C?

Accepted Answer

A)  15 map units 
B)  35 map units 
C)  either 15 map units or 35 map units,depending on the order of the genes 
D)  The map distance between A and C can not be predicted from these data. 
E)  5 map units 
A)  15 map units 
B)  35 map units 
C)  either 15 map units or 35 map units,depending on the order of the genes 
D)  The map distance between A and C can not be predicted from these data. 
E)  5 map units

Question 19

In fruit flies,the recessive pr and cn mutations cause brown and bright-red eyes,respectively (wild-type flies have brick-red eyes).The double mutant pr cn combination has orange eyes.A female who has wild-type eyes is crossed to an orange-eyed male.Their progeny have the following distribution of eye colours: $$\begin{array} { | l | r | } 
\hline \text { wild-type } & 8 \
\hline \text { brown } & 241 \
\hline \text { bright-red } & 239 \
\hline \text { orange } & 12 \
\hline & 500 \
\hline
\end{array}$$
Which classes are the parental types?

Accepted Answer

A)  wild-type and orange 
B)  brown and bright-red 
C)  wild-type and brown 
D)  bright-red and orange 
E)  There is no way to determine this. 
A)  wild-type and orange 
B)  brown and bright-red 
C)  wild-type and brown 
D)  bright-red and orange 
E)  There is no way to determine this.

Question 20

Suppose the L and M genes are on the same chromosome but separated by 100 map units.What fraction of the progeny from the cross LM/lm × lm/lm would be Lm/lm?

Accepted Answer

A)  10% 
B)  25% 
C)  50% 
D)  75% 
E)  100% 
A)  10% 
B)  25% 
C)  50% 
D)  75% 
E)  100%

Chiasmata are structures of cross over between non-sister chromatids of homologous chromosomes.

In an individual with genotype Lpq/lPQ the L gene is in the middle.What would be the genotypes of the gametes produced by a double crossover surrounding the L locus?

Some of the larger human chromosomes typically contain multiple chiasmata during meiotic prophase.If you were to carefully study the distribution of these chiasmata,what would you find?

When mapping three genes,why do geneticists prefer to do one three-point cross rather than three two-point crosses? Give two reasons.

Which of the following processes can generate recombinant gametes?

How does Mendel's law of independent assortment relate to the concept of linkage?

The map of a chromosome interval is Q-10 m.u.-R-40 m.u.-S.Which interval would likely show the higher ratio of double to single chiasmata?

Genetic mapping distance calculated for a chromosome is directly related to physical distance along that chromosome.

What are chiasmata?

Individuals heterozygous for the RB⁺ and RB^- alleles can develop tumours as a result of

The measured distance between genes D and E in a two-point test cross is 50 map units.What does this mean in physical terms?

Recombination due to crossing over occurs only rarely in mitosis.

The R/r and S/s genes are linked and 10 map units apart.In the cross Rs/rS × rs/rs what fraction of the progeny will be RS/rs?

The zipper-like connection between paired homologs in early prophase is known as a

In Drosophila,the genes y,f,and v are all X-linked.y f v females are crossed to wild-type males and the F₁ females are test-crossed.The F₂ are distributed as follows. yfv 3210 yf+ 72 y+v 1024 y++ 678 +fv 690 +f+ 1044 ++v 60 +++ 10,000 State what a coefficient of coincidence of 0.5 would mean.

If the map distance between genes A and B is 10 map units and the map distance between genes B and C is 25 map units,what is the map distance between genes A and C?

Suppose the L and M genes are on the same chromosome but separated by 100 map units.What fraction of the progeny from the cross LM/lm × lm/lm would be Lm/lm?

Mendels Principles of Heredity

Extensions to Mendels Laws

Linkage, Recombination, and the Mapping of Genes on Chromosomes

Dna Structure, Replication, and Recombination

Anatomy and Function of a Gene: Dissection Through Mutation

Gene Expression: the Flow of Information From Dna to Rna to Protein

Digital Analysis of Genomes

Genome Annotation

Analyzing Genomic Variation

The Eukaryotic Chromosome

Chromosomal Rearrangements and Changes in Chromosome Number

Bacterial Genetics

Organellar Inheritance

Gene Regulation in Prokaryotes

Gene Regulation in Eukaryotes

Manipulating the Genomes of Eukaryotes

The Genetic Analysis of Development

The Genetics of Cancer

Variation and Selection in Populations

Genetics of Complex Traits

Exploring Synthetic Biology: Concepts, Techniques, and Applications

Filters

Exam 3: The Chromosome Theory of Inheritance

Chiasmata are structures of cross over between non-sister chromatids of homologous chromosomes.

In an individual with genotype Lpq/lPQ the L gene is in the middle.What would be the genotypes of the gametes produced by a double crossover surrounding the L locus?

Some of the larger human chromosomes typically contain multiple chiasmata during meiotic prophase.If you were to carefully study the distribution of these chiasmata,what would you find?

When mapping three genes,why do geneticists prefer to do one three-point cross rather than three two-point crosses? Give two reasons.

Which of the following processes can generate recombinant gametes?

How does Mendel's law of independent assortment relate to the concept of linkage?

The map of a chromosome interval is Q-10 m.u.-R-40 m.u.-S.Which interval would likely show the higher ratio of double to single chiasmata?

Genetic mapping distance calculated for a chromosome is directly related to physical distance along that chromosome.

What are chiasmata?

Individuals heterozygous for the RB+ and RB- alleles can develop tumours as a result of

The measured distance between genes D and E in a two-point test cross is 50 map units.What does this mean in physical terms?

Recombination due to crossing over occurs only rarely in mitosis.

The R/r and S/s genes are linked and 10 map units apart.In the cross Rs/rS × rs/rs what fraction of the progeny will be RS/rs?

The zipper-like connection between paired homologs in early prophase is known as a

In Drosophila,the genes y,f,and v are all X-linked.y f v females are crossed to wild-type males and the F1 females are test-crossed.The F2 are distributed as follows. yfv 3210 yf+ 72 y+v 1024 y++ 678 +fv 690 +f+ 1044 ++v 60 +++ 10,000 State what a coefficient of coincidence of 0.5 would mean.

If the map distance between genes A and B is 10 map units and the map distance between genes B and C is 25 map units,what is the map distance between genes A and C?

Suppose the L and M genes are on the same chromosome but separated by 100 map units.What fraction of the progeny from the cross LM/lm × lm/lm would be Lm/lm?

Mendels Principles of Heredity

Extensions to Mendels Laws

Linkage, Recombination, and the Mapping of Genes on Chromosomes

Dna Structure, Replication, and Recombination

Anatomy and Function of a Gene: Dissection Through Mutation

Gene Expression: the Flow of Information From Dna to Rna to Protein

Digital Analysis of Genomes

Genome Annotation

Analyzing Genomic Variation

The Eukaryotic Chromosome

Chromosomal Rearrangements and Changes in Chromosome Number

Bacterial Genetics

Organellar Inheritance

Gene Regulation in Prokaryotes

Gene Regulation in Eukaryotes

Manipulating the Genomes of Eukaryotes

The Genetic Analysis of Development

The Genetics of Cancer

Variation and Selection in Populations

Genetics of Complex Traits

Exploring Synthetic Biology: Concepts, Techniques, and Applications

Filters

Individuals heterozygous for the RB⁺ and RB^- alleles can develop tumours as a result of

In Drosophila,the genes y,f,and v are all X-linked.y f v females are crossed to wild-type males and the F₁ females are test-crossed.The F₂ are distributed as follows. yfv 3210 yf+ 72 y+v 1024 y++ 678 +fv 690 +f+ 1044 ++v 60 +++ 10,000 State what a coefficient of coincidence of 0.5 would mean.