Question 1

Sister chromatids separate during

Accepted Answer

A) anaphase I. 
B) metaphase I. 
C) anaphase II. 
D) interkinesis. 
A) anaphase I. 
B) metaphase I. 
C) anaphase II. 
D) interkinesis. C

Question 2

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) 7 
A) 13 
B) 26 
C) 46 
D) 7 B

Question 3

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

Question 4

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. 
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.

Question 5

-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;8 
A) 2;2 
B) 4;4 
C) 2;4 
D) 2;8 
E) 4;8 F)8;8

Question 6

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. 
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.

Question 7

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. 
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.

Question 8

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;triploid 
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;triploid

Question 9

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. 
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.

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,d 
A) a,c,d,b 
B) c,a,b,d 
C) c,a,d,b 
D) a,b,c,d

Question 11

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 over 
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 over

Question 12

-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;4 
A) 1;1 
B) 1;2 
C) 2;2 
D) 1;4 
E) 2;4

Question 13

Centromeres split and sister chromosomes migrate to opposite poles in

Accepted Answer

A) anaphase I. 
B) prophase II. 
C) anaphase II. 
D) telophase II. 
A) anaphase I. 
B) prophase II. 
C) anaphase II. 
D) telophase II.

Question 14

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 number 
A) four 
B) two 
C) eight 
D) a diploid number

Question 15

Which of the following would enable you to detect aneuploidy?

Accepted Answer

A) autosomy 
B) karyotyping 
C) syngamy 
D) synapsis 
A) autosomy 
B) karyotyping 
C) syngamy 
D) synapsis

Question 16

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. 
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.

Question 17

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

Question 18

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) synapsis 
A) DNA replication 
B) cytokinesis 
C) anaphase I 
D) synapsis

Question 19

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. 
A) prophase I. 
B) metaphase I. 
C) prophase II. 
D) metaphase II.

Question 20

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

Exam 12: Meiosis

Sister chromatids separate during

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

Genetic recombination takes place in which of the following processes?

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.)

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

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

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?

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

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?

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.

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 ________.

-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).

Centromeres split and sister chromosomes migrate to opposite poles in

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

Which of the following would enable you to detect aneuploidy?

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

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?

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

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

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

Biology and the Tree of Life

Water and Carbon: the Chemical Basis of Life

Protein Structure and Function

Nucleic Acids and the Rna World

An Introduction to Carbohydrates

Lipids, membranes, and the First Cells

Inside the Cell

Cell-Cell Interactions

Cellular Respiration and Fermentation

Photosynthesis

The Cell Cycle

Mendel and the Gene

Dna and the Gene: Synthesis and Repair

How Genes Work

Transcription, RNA Processing, and Translation

Control of Gene Expression in Bacteria

Control of Gene Expression in Eukaryotes

Analyzing and Engineering Genes

Genomics

Principles of Development

An Introduction to Animal Development

An Introduction to Plant Development

Evolution by Natural Selection

Evolutionary Processes

Speciation

Phylogenies and the History of Life

Bacteria and Archaea

Protists

Green Algae and Land Plants

Fungi

An Introduction to Animals

Protostome Animals

Deuterostome Animals

Viruses

Plant Form and Function

Water and Sugar Transport in Plants

Plant Nutrition

Plant Sensory Systems, signals, and Responses

Plant Reproduction

Animal Form and Function

Water and Electrolyte Balance in Animals

Animal Nutrition

Gas Exchange and Circulation

Electrical Signals in Animals

Animal Sensory Systems and Movement

Chemical Signals in Animals

Animal Reproduction

The Immune System in Animals

An Introduction to Ecology

Behavioural Ecology

Population Ecology

Community Ecology

Ecosystems

Biodiversity and Conservation Biology

Filters

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

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 .

-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).