Question 1

What was the experimental focus of the preliminary genetic screening performed by Nüsslein- Volhard and Wieschaus?

Accepted Answer

A)  to discover the bicoid gene 
B)  to generate two- tailed fruit- fly embryos 
C)  to identify fruit flies with mutations in genes that control fruit- fly development 
D)  to evaluate the mutagenic properties of varied treatments 
A)  to discover the bicoid gene 
B)  to generate two- tailed fruit- fly embryos 
C)  to identify fruit flies with mutations in genes that control fruit- fly development 
D)  to evaluate the mutagenic properties of varied treatments C

Question 2

When the Bicoid protein is expressed in Drosophila, the embryo is still syncytial divisions between cells are not yet fully developed). This helps to explain which observation by Nüsslein- Volhard and Wieschaus?

Accepted Answer

A)  Bicoid protein diffuses throughout the embryo in a concentration gradient. 
B)  Bicoid protein serves as a transcription regulator. 
C)  mRNA from the egg is translated into the Bicoid protein. 
D)  Bicoid protein determines the dorsoventral axis of the embryo. 
A)  Bicoid protein diffuses throughout the embryo in a concentration gradient. 
B)  Bicoid protein serves as a transcription regulator. 
C)  mRNA from the egg is translated into the Bicoid protein. 
D)  Bicoid protein determines the dorsoventral axis of the embryo. A

Question 3

For which of the following reasons are adult stem cells said to be multipotent?

Accepted Answer

A)  They can divide and develop to form a complete multicellular organism. 
B)  They can divide and develop into any part of the multicellular organism. 
C)  They can only divide and develop into a limited number of related cells types. 
A)  They can divide and develop to form a complete multicellular organism. 
B)  They can divide and develop into any part of the multicellular organism. 
C)  They can only divide and develop into a limited number of related cells types. C

Question 4

The duplication of homeotic Hox) genes has been significant in the evolution of animals because it

Accepted Answer

A)  reduced morphological diversity into simpler forms of life. 
B)  caused the extinction of major groups. 
C)  allowed animals to survive on significantly fewer calories. 
D)  permitted the evolution of novel forms. 
A)  reduced morphological diversity into simpler forms of life. 
B)  caused the extinction of major groups. 
C)  allowed animals to survive on significantly fewer calories. 
D)  permitted the evolution of novel forms.

Question 5

Muscle cells differ from nerve cells mainly because they

Accepted Answer

A)  use different genetic codes. 
B)  express different genes. 
C)  have unique ribosomes. 
D)  contain different genes. 
E)  have different chromosomes. 
A)  use different genetic codes. 
B)  express different genes. 
C)  have unique ribosomes. 
D)  contain different genes. 
E)  have different chromosomes.

Question 6

Cells in a developing embryo are subject to a number of regulatory pressures. Which of the following is NOT a source of regulatory signals in animal development?

Accepted Answer

A)  nearby cells 
B)  sperm nucleus 
C)  extracellular matrix 
D)  oocyte cytoplasm 
A)  nearby cells 
B)  sperm nucleus 
C)  extracellular matrix 
D)  oocyte cytoplasm

Question 7

During Drosophila development, there is a regulatory cascade of gene activation. The proper sequence for this cascade is

Accepted Answer

A)  bicoid, pair- rule genes, gap genes, and segment polarity genes. 
B)  bicoid, segment- polarity genes, gap genes, and pair- rule genes. 
C)  bicoid, gap genes, segment polarity genes, and pair- rule genes. 
D)  bicoid, gap genes, pair- rule genes, and segment polarity genes. 
A)  bicoid, pair- rule genes, gap genes, and segment polarity genes. 
B)  bicoid, segment- polarity genes, gap genes, and pair- rule genes. 
C)  bicoid, gap genes, segment polarity genes, and pair- rule genes. 
D)  bicoid, gap genes, pair- rule genes, and segment polarity genes.

Question 8

Which of the following is true of the cloning experiment that resulted in Dolly the sheep?

Accepted Answer

A)  Dolly was genetically identical to the egg- cell donor. 
B)  Dolly was cloned by fusing the nuclei from two separate eggs harvested from the same individual. 
C)  Dolly was cloned by fusing an egg with an embryonic stem cell. 
D)  Dolly was infertile, which indicated incomplete nuclear reprogramming. 
E)  Dolly was cloned by using a differentiated cell fused to an egg from another breed of sheep. 
A)  Dolly was genetically identical to the egg- cell donor. 
B)  Dolly was cloned by fusing the nuclei from two separate eggs harvested from the same individual. 
C)  Dolly was cloned by fusing an egg with an embryonic stem cell. 
D)  Dolly was infertile, which indicated incomplete nuclear reprogramming. 
E)  Dolly was cloned by using a differentiated cell fused to an egg from another breed of sheep.

Question 9

Suppose the protein specified by bicoid were injected into Drosophila embryos, so that a high concentration was present everywhere in the embryo. What might be the result of such an experiment?

Accepted Answer

A)  The embryos would halt their development. 
B)  The embryos would show no development of posterior regions. 
C)  The embryos would show no development of anterior regions. 
D)  The embryos would grow larger than normal. 
A)  The embryos would halt their development. 
B)  The embryos would show no development of posterior regions. 
C)  The embryos would show no development of anterior regions. 
D)  The embryos would grow larger than normal.

Question 10

During development, what a cell differentiates into depends in part on its location along three body axes. Which axis runs towards the organism's head?

Accepted Answer

A)  ventral 
B)  dorsal 
C)  anterior 
D)  posterior 
A)  ventral 
B)  dorsal 
C)  anterior 
D)  posterior

Question 11

Suppose the pair- rule genes were inactivated in Drosophila embryos. What is the likely result of the experiment?

Accepted Answer

A)  The embryos would have missing alternate segments. 
B)  The embryos would develop normally. 
C)  The embryos would have impaired anterior- posterior polarity. 
D)  The embryos would lack several segments. 
A)  The embryos would have missing alternate segments. 
B)  The embryos would develop normally. 
C)  The embryos would have impaired anterior- posterior polarity. 
D)  The embryos would lack several segments.

Question 12

Communication within and between cells of an embryo can include all of the following EXCEPT

Accepted Answer

A)  increased concentration of signaling molecules. 
B)  changes in gene transcription. 
C)  changes in gene sequences. 
D)  changes in binding to regulatory sequences. 
A)  increased concentration of signaling molecules. 
B)  changes in gene transcription. 
C)  changes in gene sequences. 
D)  changes in binding to regulatory sequences.

Question 13

Cloning of plants from cuttings demonstrates that

Accepted Answer

A)  differentiated cells may contain embryonic mRNAs. 
B)  genetic information is retained in mature plant cells. 
C)  genetic information is lost during plant development. 
D)  plants can reverse the differentiation process. 
A)  differentiated cells may contain embryonic mRNAs. 
B)  genetic information is retained in mature plant cells. 
C)  genetic information is lost during plant development. 
D)  plants can reverse the differentiation process.

Question 14

Gastrulation is an important event in early embryonic development. Which of the following is NOT a result of this process?

Accepted Answer

A)  determination of cell types as a result of cell-cell interactions 
B)  movement and alignment of many embryonic cells 
C)  formation of three embryonic cell layers 
D)  formation of specialized plant tissues 
A)  determination of cell types as a result of cell-cell interactions 
B)  movement and alignment of many embryonic cells 
C)  formation of three embryonic cell layers 
D)  formation of specialized plant tissues

Question 15

Which of the following terms refers to a cell that is capable of dividing and developing into a limited number of cell types in a multicellular organism?

Accepted Answer

A)  pluripotent 
B)  totipotent 
C)  multipotent 
A)  pluripotent 
B)  totipotent 
C)  multipotent

Question 16

One form of programmed cell death is apoptosis. In which developmental situation would you predict apoptosis would NOT play a major role?

Accepted Answer

A)  growth of nerves and blood vessels into a body segment 
B)  destroying embryonic nerve cells as part of "wiring" an effective nervous system 
C)  elimination of dangerous immune cells 
D)  sculpting of digits in the developing hindlimb 
A)  growth of nerves and blood vessels into a body segment 
B)  destroying embryonic nerve cells as part of "wiring" an effective nervous system 
C)  elimination of dangerous immune cells 
D)  sculpting of digits in the developing hindlimb

Question 17

All of the following are true of embryonic stem cells EXCEPT that

Accepted Answer

A)  they retain the potential to become different types of cells. 
B)  they are terminally differentiated. 
C)  they can be found in human blastocysts. 
D)  they continue to undergo mitosis when most cells have stopped dividing. 
A)  they retain the potential to become different types of cells. 
B)  they are terminally differentiated. 
C)  they can be found in human blastocysts. 
D)  they continue to undergo mitosis when most cells have stopped dividing.

Question 18

Cellular differentiation results from

Accepted Answer

A)  changes in the genetic makeup of cells. 
B)  mutations in DNA. 
C)  differential gene expression. 
A)  changes in the genetic makeup of cells. 
B)  mutations in DNA. 
C)  differential gene expression.

Question 19

Which of the following would constitute evidence that differentiated cells retain all the genes of developing cells?

Accepted Answer

A)  Differentiated cells lose their polarity if removed from the organism. 
B)  Developing cells have many mRNA transcripts that can hybridize with DNA from mature cells. 
C)  Nuclei from mature cells can direct the development of an entire individual. 
D)  Differentiated cells generally synthesize a specific group of proteins. 
A)  Differentiated cells lose their polarity if removed from the organism. 
B)  Developing cells have many mRNA transcripts that can hybridize with DNA from mature cells. 
C)  Nuclei from mature cells can direct the development of an entire individual. 
D)  Differentiated cells generally synthesize a specific group of proteins.

Question 20

When is a cell considered differentiated?

Accepted Answer

A)  when a cell is part of recognizable tissues or organs 
B)  when a cell first becomes irreversibly committed to a particular fate 
C)  when a cell begins its pattern formation 
D)  when a cell manufactures proteins that are specific to a particular cell type 
A)  when a cell is part of recognizable tissues or organs 
B)  when a cell first becomes irreversibly committed to a particular fate 
C)  when a cell begins its pattern formation 
D)  when a cell manufactures proteins that are specific to a particular cell type

Exam 21: Gene Structure and Development

What was the experimental focus of the preliminary genetic screening performed by Nüsslein- Volhard and Wieschaus?

When the Bicoid protein is expressed in Drosophila, the embryo is still syncytial divisions between cells are not yet fully developed). This helps to explain which observation by Nüsslein- Volhard and Wieschaus?

For which of the following reasons are adult stem cells said to be multipotent?

The duplication of homeotic Hox) genes has been significant in the evolution of animals because it

Muscle cells differ from nerve cells mainly because they

Cells in a developing embryo are subject to a number of regulatory pressures. Which of the following is NOT a source of regulatory signals in animal development?

During Drosophila development, there is a regulatory cascade of gene activation. The proper sequence for this cascade is

Which of the following is true of the cloning experiment that resulted in Dolly the sheep?

Suppose the protein specified by bicoid were injected into Drosophila embryos, so that a high concentration was present everywhere in the embryo. What might be the result of such an experiment?

During development, what a cell differentiates into depends in part on its location along three body axes. Which axis runs towards the organism's head?

Suppose the pair- rule genes were inactivated in Drosophila embryos. What is the likely result of the experiment?

Communication within and between cells of an embryo can include all of the following EXCEPT

Cloning of plants from cuttings demonstrates that

Gastrulation is an important event in early embryonic development. Which of the following is NOT a result of this process?

Which of the following terms refers to a cell that is capable of dividing and developing into a limited number of cell types in a multicellular organism?

One form of programmed cell death is apoptosis. In which developmental situation would you predict apoptosis would NOT play a major role?

All of the following are true of embryonic stem cells EXCEPT that

Cellular differentiation results from

Which of the following would constitute evidence that differentiated cells retain all the genes of developing cells?

When is a cell considered differentiated?

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

Energy and Enzymes

Cellular Respiration and Fermentation

Photosynthesis

Cellcell Interactions

The Cell Cycle

Meiosis

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

The Molecular Revolution: Biotechnology and Beyond

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 and Development

Animal Form and Function

Water and Electrolyte Balance in Animals

Animal Nutrition

Gas Exchange and Circulation

Animal Nervous Systems

Animal Sensory Systems

Animal Movement

Chemical Signals in Animals

Animal Reproduction and Development

The Immune System in Animals

An Introduction to Ecology

Behavioural Ecology

Population Ecology

Community Ecology

Ecosystems and Global Ecology

Biodiversity and Conservation Biology

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