Question 1

Genetic recombination takes place in which of the following processes?

Accepted Answer

A)  anaphase I of meiosis
B)  alignment of tetrads in metaphase I
C)  crossing over
D)  random alignment of homologous chromosomes in meiosis IE) A) and B)
F) A) and C) C

Question 2

Adaptation to a changing environment is likely to occurs most quickly through which of the following processes?

Accepted Answer

A)  mutation
B)  asexual reproduction and genetic recombination
C)  sexual reproductionD) A) and B)
E) A) and C)

Question 3

Hexaploid wheat was produced synthetically by He and coworkers.They mated the diploid species,Aegilops tauschii,and the tetraploid species,T.turgidum.Which of the following is an accurate statement about the relative contribution of each parent to the genome of the hexaploid offspring?

Accepted Answer

A)  Each parent contributed equally to the genome of the offspring.
B)  Aegilops tauschii contributed four chromosomes by failing to complete meiosis after chromosome replication,and T.turgidum contributed two chromosomes.
C)  Aegilops tauschii contributed two chromosomes,and T.turgidum contributed four chromosomes.
D)  The hexaploid number appeared following mitosis with no subsequent cell division.E) B) and D)
F) B) and C)

Question 4

Figure 12.2 
-The karyotype shown above is that of a snail,Pomacea patula catemacensis.What is the diploid number for this organism?

Accepted Answer

A)  13
B)  26
C)  46
D)  7E) C) and D)
F) A) and B) B

Question 5

Which of the following is the difference between trisomy and triploidy?

Accepted Answer

A)  Trisomic individuals have three copies of a specific chromosome;triploid individuals have three copies of every chromosome.
B)  Trisomic individuals have three copies of every chromosome;triploid individuals have three copies of a specific chromosome.
C)  There is no difference between the two terms-they mean the same thing.
D)  Trisomic individuals have three copies of one gene on one chromosome;triploidE) A) and B)
F) B) and D)

Question 6

Centromeres split and sister chromosomes migrate to opposite poles in

Accepted Answer

A)  anaphase I.
B)  prophase II.
C)  anaphase II.
D)  telophase II.E) All of the above
F) B) and C)

Question 7

-Just prior to meiosis,DNA is replicated.Each resulting piece of replicated DNA is considered to be ________ chromosome(s) and is made up of ________ chromatic(s) .

Accepted Answer

A)  1;1
B)  1;2
C)  2;2
D)  1;4
E)  2;4F) B) and E)
G) A) and B)

Question 8

The bulldog ant has a diploid number of two chromosomes.Therefore,following meiosis,each daughter cell will have a single chromosome.There is/are ________ different possible combination(s) of genes in the daughter cells of meiosis because ________.

Accepted Answer

A)  one;there is only one chromosome per cell
B)  two;there are two homologous chromosomes per cell prior to meiosis
C)  more than 2;the two homologues cross overD) B) and C)
E) A) and C)

Question 9

Crossover,the exchange of segments of homologous chromosomes,takes place during which of the following processes?

Accepted Answer

A)  DNA replication
B)  cytokinesis
C)  anaphase I
D)  synapsisE) A) and D)
F) All of the above

Question 10

Figure 12.4 
-Refer to Figure 12.4.Put the stages of meiosis shown here in the order that they would occur in a cell.

Accepted Answer

A)  a,c,d,b
B)  c,a,b,d
C)  c,a,d,b
D)  a,b,c,dE) B) and C)
F) A) and D)

Question 11

Sister chromatids separate during

Accepted Answer

A)  anaphase I.
B)  metaphase I.
C)  anaphase II.
D)  interkinesis.E) A) and C)
F) B) and C) C

Question 12

Which of the following would enable you to detect aneuploidy?

Accepted Answer

A)  autosomy
B)  karyotyping
C)  syngamy
D)  synapsisE) A) and B)
F) A) and C)

Question 13

Chromosomes and their homologues align at the equator of the cell during

Accepted Answer

A)  prophase I.
B)  metaphase I.
C)  prophase II.
D)  metaphase II.E) C) and D)
F) A) and B)

Question 14

What happens when an individual has an odd number of chromosome sets (e.g.,triploidy) ?

Accepted Answer

A)  They produce offspring with an even number of chromosome sets (e.g.,tetraploid,hexaploid) .
B)  Their offspring are often sterile.
C)  They go through three sets of meiosis (meiosis I,meiosis II,and meiosis III) 
D)  Their cells are unable to complete meiosis.E) B) and D)
F) A) and D)

Question 15

Figure 12.1 
-What can you infer from the karyotype shown in Figure 12.1?

Accepted Answer

A)  There is a translocation in one of the chromosome 8 homologues.
B)  This individual has a single sex chromosome.
C)  This individual has an abnormal number of autosomes.
D)  This is a karyotype of a male.E) B) and D)
F) All of the above

Question 16

In 1985,Hassold and Chiu found that the likelihood of miscarriage increased with maternal age.What is the most likely explanation for the relationship between age and miscarriage?

Accepted Answer

A)  Women in their mid-thirties and older have more health problems that interfere with their ability to maintain pregnancy.
B)  Older women typically have hormonal imbalances that prevent them from carrying a baby to term.
C)  The DNA replication that takes place immediately prior to meiosis is less accurate in older women.
D)  Ova are arrested in meiosis until ovulation.As a result,completion of meiosis in the older woman is more likely to result in aneuploidy or other chromosomal abnormalities.E) None of the above
F) A) and D)

Question 17

-In the diploid cell above there are ________ chromosomes and ________ chromatids.

Accepted Answer

A)  2;2
B)  4;4
C)  2;4
D)  2;8
E)  4;8 F) 8;8F) C) and D)
G) B) and C)

Question 18

Somatic cells of roundworms have four chromosomes.How many chromosomes would you find in an ovum from a roundworm?

Accepted Answer

A)  four
B)  two
C)  eight
D)  a diploid numberE) A) and B)
F) None of the above

Question 19

Different types of organisms have different types of life cycles."Alternation of generations" is a life cycle found among land plants and several groups of algae.It is characterized by which of the following?

Accepted Answer

A)  a multicellular diploid state
B)  a multicellular haploid state
C)  tetraploidy
D)  both a multicellular diploid state and a multicellular haploid stateE) A) and D)
F) B) and C)

Question 20

Why might the incidence of trisomy from maternal origin be higher than that from paternal origin? 
Source: Hassold,T.,Chiu,D.Human Genetics.1985;70(1) :11-7.)

Accepted Answer

A)  Eggs are arrested in meiosis in the mother from approximately birth until ovulation.
B)  Sperm travel to the site of fertilization,and an extra chromosome may slow them down.
C)  Eggs move little from their site of release to the site of fertilization.
D)  All of the above are possible explanations for the higher incidence of trisomy of maternal origin.E) B) and C)
F) A) and D)

Exam 12: Meiosis

Genetic recombination takes place in which of the following processes?

Correct AnswerverifiedC

Adaptation to a changing environment is likely to occurs most quickly through which of the following processes?

Correct AnswerverifiedShow Answer

Hexaploid wheat was produced synthetically by He and coworkers.They mated the diploid species,Aegilops tauschii,and the tetraploid species,T.turgidum.Which of the following is an accurate statement about the relative contribution of each parent to the genome of the hexaploid offspring?

Correct AnswerverifiedShow Answer

Figure 12.2 -The karyotype shown above is that of a snail,Pomacea patula catemacensis.What is the diploid number for this organism?

Correct AnswerverifiedB

Which of the following is the difference between trisomy and triploidy?

Correct AnswerverifiedShow Answer

Centromeres split and sister chromosomes migrate to opposite poles in

Correct AnswerverifiedShow Answer

-Just prior to meiosis,DNA is replicated.Each resulting piece of replicated DNA is considered to be ________ chromosome(s) and is made up of ________ chromatic(s) .

Correct AnswerverifiedShow Answer

The bulldog ant has a diploid number of two chromosomes.Therefore,following meiosis,each daughter cell will have a single chromosome.There is/are ________ different possible combination(s) of genes in the daughter cells of meiosis because ________.

Correct AnswerverifiedShow Answer

Crossover,the exchange of segments of homologous chromosomes,takes place during which of the following processes?

Correct AnswerverifiedShow Answer

Figure 12.4 -Refer to Figure 12.4.Put the stages of meiosis shown here in the order that they would occur in a cell.

Correct AnswerverifiedShow Answer

Sister chromatids separate during

Correct AnswerverifiedC

Which of the following would enable you to detect aneuploidy?

Correct AnswerverifiedShow Answer

Chromosomes and their homologues align at the equator of the cell during

Correct AnswerverifiedShow Answer

What happens when an individual has an odd number of chromosome sets (e.g.,triploidy) ?

Correct AnswerverifiedShow Answer

Figure 12.1 -What can you infer from the karyotype shown in Figure 12.1?

Correct AnswerverifiedShow Answer

In 1985,Hassold and Chiu found that the likelihood of miscarriage increased with maternal age.What is the most likely explanation for the relationship between age and miscarriage?

Correct AnswerverifiedShow Answer

-In the diploid cell above there are ________ chromosomes and ________ chromatids.

Correct AnswerverifiedShow Answer

Somatic cells of roundworms have four chromosomes.How many chromosomes would you find in an ovum from a roundworm?

Correct AnswerverifiedShow Answer

Different types of organisms have different types of life cycles."Alternation of generations" is a life cycle found among land plants and several groups of algae.It is characterized by which of the following?

Correct AnswerverifiedShow Answer

Why might the incidence of trisomy from maternal origin be higher than that from paternal origin? Source: Hassold,T.,Chiu,D.Human Genetics.1985;70(1) :11-7.)

Correct AnswerverifiedShow Answer

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C

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B

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-Just prior to meiosis,DNA is replicated.Each resulting piece of replicated DNA is considered to be chromosome(s) and is made up of chromatic(s) .

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The bulldog ant has a diploid number of two chromosomes.Therefore,following meiosis,each daughter cell will have a single chromosome.There is/are different possible combination(s) of genes in the daughter cells of meiosis because .

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C

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-In the diploid cell above there are chromosomes and chromatids.

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