Question 1

How were mutants used to order the sevenless-Ras pathway?

Accepted Answer

A) Cells that expressed a constitutively active Ras mutant protein did not require Sevenless activation to become R7. 
B) Cells that expressed a constitutively active Sevenless mutant protein did not require Ras activation to become R7. 
C) Cells that expressed an inactive Ras mutant protein did not require Sevenless activation to become R7. 
D) Cells that expressed a constitutively-inactive Sevenless mutant protein did not require Ras activation to become R7. 
A) Cells that expressed a constitutively active Ras mutant protein did not require Sevenless activation to become R7. 
B) Cells that expressed a constitutively active Sevenless mutant protein did not require Ras activation to become R7. 
C) Cells that expressed an inactive Ras mutant protein did not require Sevenless activation to become R7. 
D) Cells that expressed a constitutively-inactive Sevenless mutant protein did not require Ras activation to become R7. A

Question 2

What is a major advantage of using a modifier screen as opposed to a primary screen?

Accepted Answer

A) Modifier screens can be used to identify pleiotropic genes. 
B) Modifier screens are easier to perform. 
C) Modifier screens use a random selection of flies based on their morphology and therefore should identify all genes involved in development. 
D) Modifier screens are performed with chemically mutagenized flies so all genes that affect development should be identified more rapidly than screening for spontaneous mutants. 
A) Modifier screens can be used to identify pleiotropic genes. 
B) Modifier screens are easier to perform. 
C) Modifier screens use a random selection of flies based on their morphology and therefore should identify all genes involved in development. 
D) Modifier screens are performed with chemically mutagenized flies so all genes that affect development should be identified more rapidly than screening for spontaneous mutants. A

Question 3

The presence of a homeodomain in a protein suggests what about its function?

Accepted Answer

A) It has kinase activity. 
B) It is a membrane bound receptor. 
C) It is a secreted protein. 
D) It is a transcription factor. 
A) It has kinase activity. 
B) It is a membrane bound receptor. 
C) It is a secreted protein. 
D) It is a transcription factor. D

Question 4

A homeodomain is a region within a protein that

Accepted Answer

A) acts as a receptor. 
B) has kinase activity. 
C) binds to specific base pair sequences. 
D) binds to transcription factors. 
A) acts as a receptor. 
B) has kinase activity. 
C) binds to specific base pair sequences. 
D) binds to transcription factors.

Question 5

The pattern of embryonic expression for a specific gene shown by RNA in situ hybridization and a GFP fusion protein will always be identical.

Accepted Answer

A) True 
 B)False

Question 6

In Drosophila, two maternal transcripts that are distributed evenly throughout the oocyte prior to fertilization are

Accepted Answer

A) caudal and knirps. 
B) bicoid and nanos. 
C) caudal and hunchback. 
D) sevenless and even-skipped. 
A) caudal and knirps. 
B) bicoid and nanos. 
C) caudal and hunchback. 
D) sevenless and even-skipped.

Question 7

How do genetic mosaics help determine the focus of action of a gene?

Accepted Answer

A) Mosaics are composed of cells with different genotypes, so the phenotype of the cells that lack a gene product can be compared to that of neighboring cells that have the gene product. 
B) Mosaics are created by mating flies that are homozygous recessive for two different genes and the morphology of the double mutant progeny is studied. 
C) Mosaics are created by mating two flies that carry homozygous gain-of-function mutations in different genes and the effects of the mutations on the morphology studied. 
D) Mosaics are created by the Cre-loxP system which allows for the deletion of specific genes at controlled stages of development. 
A) Mosaics are composed of cells with different genotypes, so the phenotype of the cells that lack a gene product can be compared to that of neighboring cells that have the gene product. 
B) Mosaics are created by mating flies that are homozygous recessive for two different genes and the morphology of the double mutant progeny is studied. 
C) Mosaics are created by mating two flies that carry homozygous gain-of-function mutations in different genes and the effects of the mutations on the morphology studied. 
D) Mosaics are created by the Cre-loxP system which allows for the deletion of specific genes at controlled stages of development.

Question 8

Nurse cells surround Drosophila oocytes and produce maternal mRNA and proteins that are deposited into the egg.Which of the following products would be produced by nurse cells?

Accepted Answer

A) bicoid mRNA 
B) Antp mRNA 
C) Caudal protein 
D) Hedgehog protein 
A) bicoid mRNA 
B) Antp mRNA 
C) Caudal protein 
D) Hedgehog protein

Question 9

RNAi

Accepted Answer

A) depletes the mRNAs of specific genes. 
B) uses dsRNA to bind to transcription factors. 
C) can be used to create functional knockin mutants. 
D) is not useful for the study of development. 
A) depletes the mRNAs of specific genes. 
B) uses dsRNA to bind to transcription factors. 
C) can be used to create functional knockin mutants. 
D) is not useful for the study of development.

Question 10

Which statement describes a primary mutant screen?

Accepted Answer

A) A researcher uses CRISPR to create mutations in mouse homologs of three genes that function in heart development in the fruit fly. 
B) A scientist uses RNAi to simultaneously knock down the expression of two genes in C.elegans to determine whether they function redundantly. 
C) A scientist examines a large number of mutagenized zebrafish embryos for abnormalities in blood vessel formation. 
D) A researcher treats a large number of Arabidopsis plants with different chemicals to determine which chemicals inhibit plant growth. 
A) A researcher uses CRISPR to create mutations in mouse homologs of three genes that function in heart development in the fruit fly. 
B) A scientist uses RNAi to simultaneously knock down the expression of two genes in C.elegans to determine whether they function redundantly. 
C) A scientist examines a large number of mutagenized zebrafish embryos for abnormalities in blood vessel formation. 
D) A researcher treats a large number of Arabidopsis plants with different chemicals to determine which chemicals inhibit plant growth.

Question 11

How are temperature sensitive mutants used to determine when genes act during development?

Accepted Answer

A) Embryos can be shifted to the restrictive temperature to inactivate the mutant gene and the effect of inactivation on subsequent stages can be observed. 
B) Embryos can be shifted to the permissive temperature to inactivate the mutant gene and the effect of inactivation on subsequent stages observed. 
C) Embryos can be incubated at the restrictive temperature for several hours.If the embryo develops normally, then the gene product is required during that period of development. 
D) Embryos can be raised at the permissive temperature and if the embryo does not die, then the gene product is not required for development. 
A) Embryos can be shifted to the restrictive temperature to inactivate the mutant gene and the effect of inactivation on subsequent stages can be observed. 
B) Embryos can be shifted to the permissive temperature to inactivate the mutant gene and the effect of inactivation on subsequent stages observed. 
C) Embryos can be incubated at the restrictive temperature for several hours.If the embryo develops normally, then the gene product is required during that period of development. 
D) Embryos can be raised at the permissive temperature and if the embryo does not die, then the gene product is not required for development.

Question 12

The observation that ________ provides evidence that all living forms are related.

Accepted Answer

A) some organisms use mosaic determinism, whereas others use regulative determinism 
B) only histone genes are conserved 
C) many genes and genetic pathways are conserved 
D) sex determination occurs by different mechanisms in many species 
A) some organisms use mosaic determinism, whereas others use regulative determinism 
B) only histone genes are conserved 
C) many genes and genetic pathways are conserved 
D) sex determination occurs by different mechanisms in many species

Question 13

Which of the choices gives the correct sequence of early embryonic development in Drosophila?

Accepted Answer

A) zygote, syncytial blastoderm, multinucleate syncytium, cellular blastoderm 
B) zygote, cellular blastoderm, syncytial blastoderm, multinucleate syncytium 
C) zygote, multinucleate syncytium, syncytial blastoderm, cellular blastoderm 
D) syncytial blastoderm, multinucleate syncytium, zygote, cellular blastoderm 
A) zygote, syncytial blastoderm, multinucleate syncytium, cellular blastoderm 
B) zygote, cellular blastoderm, syncytial blastoderm, multinucleate syncytium 
C) zygote, multinucleate syncytium, syncytial blastoderm, cellular blastoderm 
D) syncytial blastoderm, multinucleate syncytium, zygote, cellular blastoderm

Question 14

A researcher performs RNAi against a gene that is required for viability in C.elegans embryos and 70% of the embryos die during development.Some of the embryos may have survived because

Accepted Answer

A) RNAi did not eliminate the mRNA (and protein)of the gene completely. 
B) the dsRNA was used to translate additional proteins to compensate for the mRNA that was degraded. 
C) RNAi eliminated the protein product of the gene. 
D) of issues related to fertilization. 
A) RNAi did not eliminate the mRNA (and protein)of the gene completely. 
B) the dsRNA was used to translate additional proteins to compensate for the mRNA that was degraded. 
C) RNAi eliminated the protein product of the gene. 
D) of issues related to fertilization.

Question 15

Which statement best describes the limitations of using of humans in genetic studies of developmental biology?

Accepted Answer

A) The variation in human development between individuals is too large for genetic studies. 
B) It is impractical and unethical to conduct experimental manipulation or targeted mutagenesis of humans to examine the role of genes in development. 
C) It is impractical and unethical to examine and describe abnormalities of human development, such as birth defects. 
D) Genetic studies of human development are not necessary, because most problems in human development are due to environmental influences and not genetics. 
A) The variation in human development between individuals is too large for genetic studies. 
B) It is impractical and unethical to conduct experimental manipulation or targeted mutagenesis of humans to examine the role of genes in development. 
C) It is impractical and unethical to examine and describe abnormalities of human development, such as birth defects. 
D) Genetic studies of human development are not necessary, because most problems in human development are due to environmental influences and not genetics.

Question 16

Maternal effect mutations can be identified when

Accepted Answer

A) homozygous mutant females exhibit an abnormal phenotype, whereas mutant males appear wild-type. 
B) homozygous mutant females can develop normally, but their offspring exhibit a mutant phenotype. 
C) heterozygous mutant females can develop normally, but their offspring exhibit a mutant phenotype. 
D) any aspect of embryonic development is abnormal. 
A) homozygous mutant females exhibit an abnormal phenotype, whereas mutant males appear wild-type. 
B) homozygous mutant females can develop normally, but their offspring exhibit a mutant phenotype. 
C) heterozygous mutant females can develop normally, but their offspring exhibit a mutant phenotype. 
D) any aspect of embryonic development is abnormal.

Question 17

A temperature-sensitive (ts)mutation is often due to a ________ mutation that affects protein folding or activity.

Accepted Answer

A) null 
B) nonsense 
C) missense 
D) silent 
A) null 
B) nonsense 
C) missense 
D) silent

Question 18

What is the most significant advantage of using RNAi to study development?

Accepted Answer

A) Geneticists have only been able to identify a subset of the genes involved in development. 
B) Genetic studies of a single gene can be completed without creating new mutant organisms. 
C) RNA is easy to isolate. 
D) RNAi causes phenotypes not typical of in vivo development. 
A) Geneticists have only been able to identify a subset of the genes involved in development. 
B) Genetic studies of a single gene can be completed without creating new mutant organisms. 
C) RNA is easy to isolate. 
D) RNAi causes phenotypes not typical of in vivo development.

Question 19

What is the order of action of these classes of genes during Drosophila development?

Accepted Answer

A) maternal effect, gap, pair rule, segment polarity 
B) maternal effect, gap, segment polarity, pair rule 
C) maternal effect, pair rule, segment polarity, gap 
D) maternal effect, segment polarity, gap, pair rule 
A) maternal effect, gap, pair rule, segment polarity 
B) maternal effect, gap, segment polarity, pair rule 
C) maternal effect, pair rule, segment polarity, gap 
D) maternal effect, segment polarity, gap, pair rule

Question 20

Which of the following is the least important characteristic that geneticists look for in a model organism?

Accepted Answer

A) ease of cultivation 
B) rapid reproduction 
C) small size 
D) small genome 
A) ease of cultivation 
B) rapid reproduction 
C) small size 
D) small genome

Exam 19: The Genetic Analysis of Development

How were mutants used to order the sevenless-Ras pathway?

What is a major advantage of using a modifier screen as opposed to a primary screen?

The presence of a homeodomain in a protein suggests what about its function?

A homeodomain is a region within a protein that

The pattern of embryonic expression for a specific gene shown by RNA in situ hybridization and a GFP fusion protein will always be identical.

In Drosophila, two maternal transcripts that are distributed evenly throughout the oocyte prior to fertilization are

How do genetic mosaics help determine the focus of action of a gene?

Nurse cells surround Drosophila oocytes and produce maternal mRNA and proteins that are deposited into the egg.Which of the following products would be produced by nurse cells?

RNAi

Which statement describes a primary mutant screen?

How are temperature sensitive mutants used to determine when genes act during development?

The observation that ________ provides evidence that all living forms are related.

Which of the choices gives the correct sequence of early embryonic development in Drosophila?

A researcher performs RNAi against a gene that is required for viability in C.elegans embryos and 70% of the embryos die during development.Some of the embryos may have survived because

Which statement best describes the limitations of using of humans in genetic studies of developmental biology?

Maternal effect mutations can be identified when

A temperature-sensitive (ts)mutation is often due to a ________ mutation that affects protein folding or activity.

What is the most significant advantage of using RNAi to study development?

What is the order of action of these classes of genes during Drosophila development?

Which of the following is the least important characteristic that geneticists look for in a model organism?

Genetics: the Study of Biological Information

Mendels Principles of Heredity

Extensions to Mendels Laws

The Chromosome Theory of Inheritance

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 Dna

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 Genetics of Cancer

Variation and Selection in Populations

The Genetics of Complex Traits

Filters