Question 1

Which observation below provides evidence that differentiated cells retain all the genes of developing cells?

Accepted Answer

A) Developing cells have many mRNA transcripts that can hybridize with DNA from mature cells. 
B) Differentiated cells generally synthesize a specific group of proteins. 
C) Nuclei from mature cells can direct the development of an entire individual. 
D) Not all mature cells are capable of differentiation. 
A) Developing cells have many mRNA transcripts that can hybridize with DNA from mature cells. 
B) Differentiated cells generally synthesize a specific group of proteins. 
C) Nuclei from mature cells can direct the development of an entire individual. 
D) Not all mature cells are capable of differentiation. C

Question 2

Cloning of plants from cuttings demonstrates that _____.

Accepted Answer

A) an individual plant cell cannot de-differentiate and then redifferentiate 
B) differentiated plant cells may contain embryonic mRNAs 
C) plants can reverse the differentiation process 
D) mature plant cells retain genetic information 
A) an individual plant cell cannot de-differentiate and then redifferentiate 
B) differentiated plant cells may contain embryonic mRNAs 
C) plants can reverse the differentiation process 
D) mature plant cells retain genetic information D

Question 3

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

Accepted Answer

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

Question 4

Modern cloning techniques have demonstrated that the vast majority of differentiated cells are genetically equivalent to developing cells in the embryo.What example below is an exception to this finding?

Accepted Answer

A) Nerve cells are often limited in their mitotic activity. 
B) In the immune system,sequences of DNA may rearrange to permit response to new pathogens. 
C) In the brain,DNA sequences may change with learned behavior. 
D) The lining of the digestive system is frequently replaced.Some of these cells may show repeats of certain DNA sequences. 
A) Nerve cells are often limited in their mitotic activity. 
B) In the immune system,sequences of DNA may rearrange to permit response to new pathogens. 
C) In the brain,DNA sequences may change with learned behavior. 
D) The lining of the digestive system is frequently replaced.Some of these cells may show repeats of certain DNA sequences.

Question 5

Suppose the protein specified by bicoid was 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 grow larger than normal. 
B) The embryos would show no development of posterior regions. 
C) The embryos would show no development of anterior regions. 
D) The embryos would halt their development. 
A) The embryos would grow larger than normal. 
B) The embryos would show no development of posterior regions. 
C) The embryos would show no development of anterior regions. 
D) The embryos would halt their development.

Question 6

Many different lineages of animals share similar pattern-formation gene complexes.The study of how these shared complexes function in evolution is termed _____.

Accepted Answer

A) convergent evolution 
B) conservative evolution 
C) regulatory evolution 
D) evo-devo (evolutionary developmental biology) 
A) convergent evolution 
B) conservative evolution 
C) regulatory evolution 
D) evo-devo (evolutionary developmental biology)

Question 7

What is common to gap genes,segment-polarity genes,and homeotic genes?

Accepted Answer

A) They act independently of one another. 
B) They code for transcription regulatory factors. 
C) They can be activated at any time during development. 
D) They are unique to Drosophila embryos. 
A) They act independently of one another. 
B) They code for transcription regulatory factors. 
C) They can be activated at any time during development. 
D) They are unique to Drosophila embryos.

Question 8

Suppose you found several Drosophila mutants that possessed additional legs growing out of their head segments.The probable mutation would be found in _____.

Accepted Answer

A) segment-polarity genes 
B) gap genes 
C) pair-rule genes 
D) homeotic genes 
A) segment-polarity genes 
B) gap genes 
C) pair-rule genes 
D) homeotic genes

Question 9

In snake populations,rare individuals are found that have well-developed hind limbs,but are normal in all other respects.These unusual snakes suggest that _____.

Accepted Answer

A) some snakes have mutations in Hox genes that permit development of limbs 
B) snakes retain the genes for hindlimb pattern formation,even though the genes are usually not activated during development 
C) mutations in genes that repress expression of hindlimb organizer genes can cause a snake to have limbs 
D) All of the above might explain this rare condition. 
A) some snakes have mutations in Hox genes that permit development of limbs 
B) snakes retain the genes for hindlimb pattern formation,even though the genes are usually not activated during development 
C) mutations in genes that repress expression of hindlimb organizer genes can cause a snake to have limbs 
D) All of the above might explain this rare condition.

Question 10

Gene expression in developing organisms is regulated on several different levels.In many developing animals,regulation of gene expression is influenced by the action of Hox genes.Which of the following regulatory elements is produced by many Hox genes?

Accepted Answer

A) transcriptional factors 
B) cell-surface molecules for cell-cell interactions 
C) signals from maternal cytoplasm,such as bicoid 
D) mRNA processing factors 
A) transcriptional factors 
B) cell-surface molecules for cell-cell interactions 
C) signals from maternal cytoplasm,such as bicoid 
D) mRNA processing factors

Question 11

The predominant mechanism driving cellular differentiation is the difference in gene _____.

Accepted Answer

A) expression 
B) sequences 
C) order 
D) replication 
A) expression 
B) sequences 
C) order 
D) replication

Question 12

All of the following characteristics are shared between plant and animal development except:

Accepted Answer

A) Gene expression in developing embryonic tissues is closely regulated. 
B) Orientation of cells and tissues is critical for proper development. 
C) Differentiation of cells is directed and maintained by cascades of signals. 
D) Cell types,once determined,generally cannot change their differentiated characteristics. 
A) Gene expression in developing embryonic tissues is closely regulated. 
B) Orientation of cells and tissues is critical for proper development. 
C) Differentiation of cells is directed and maintained by cascades of signals. 
D) Cell types,once determined,generally cannot change their differentiated characteristics.

Question 13

Programmed cell death,apoptosis,plays a major role in all of the following developmental situations except:
_____.

Accepted Answer

A) growth of nerves and blood vessels into a body segment 
B) sculpting of digits in the developing hindlimb 
C) growth of the atrial septum in the four-chambered mammalian heart 
D) disappearance of the embryonic tail in developing humans 
A) growth of nerves and blood vessels into a body segment 
B) sculpting of digits in the developing hindlimb 
C) growth of the atrial septum in the four-chambered mammalian heart 
D) disappearance of the embryonic tail in developing humans

Question 14

Suppose there was a mutation in the segment-polarity genes of Drosophila.What do you suppose might be the outcome?

Accepted Answer

A) Several segments of the embryo will be missing. 
B) Every other segment of the embryo will be missing. 
C) Legs will appear in the place of antennae. 
D) Antennae will appear in a different part of their usual segment. 
A) Several segments of the embryo will be missing. 
B) Every other segment of the embryo will be missing. 
C) Legs will appear in the place of antennae. 
D) Antennae will appear in a different part of their usual segment.

Question 15

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

Question 16

Scientists have found that the lifetimes of mRNAs coding for pair-rule regulatory elements in Drosophila embryos may be measured in minutes.What does this suggest about the overall developmental plan of an animal body?

Accepted Answer

A) mRNAs in general have short lifetimes;this is not a surprising finding. 
B) Each segment specified by pair-rule mRNAs is completely determined in the embryo in a very short time. 
C) Building an animal body requires a sequence of steps;each of these steps is precisely timed. 
D) Timing of pair-rule sequence determination is not as important as spatial signaling. 
A) mRNAs in general have short lifetimes;this is not a surprising finding. 
B) Each segment specified by pair-rule mRNAs is completely determined in the embryo in a very short time. 
C) Building an animal body requires a sequence of steps;each of these steps is precisely timed. 
D) Timing of pair-rule sequence determination is not as important as spatial signaling.

Question 17

All of the following are true of embryonic stem cells except _____.

Accepted Answer

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

Question 18

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

Accepted Answer

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

Question 19

In combination,what do the products of gap genes,pair-rule genes,and segmentation polarity genes of fruit flies do?

Accepted Answer

A) They trigger the reorganization of the larval body into an adult body. 
B) They define the segmented body plan of the embryo. 
C) They set up the back-to-belly axis of the larval body. 
D) They direct cell movements during differentiation. 
A) They trigger the reorganization of the larval body into an adult body. 
B) They define the segmented body plan of the embryo. 
C) They set up the back-to-belly axis of the larval body. 
D) They direct cell movements during differentiation.

Question 20

Evolutionary theory has until recently stressed genetic mutations that alter protein amino acid sequences as the major source of variation that leads to speciation.Evo-devo (evolutionary developmental biology)offers a different understanding of the role of genetic change in evolution.Which of the following statements best summarizes this understanding?

Accepted Answer

A) Genetic mutations are not as important in evolutionary change as the environment in which the organism develops. 
B) Changes in cell-cell interactions in a parent's body can lead to phenotypic change in offspring. 
C) Similar genes are found in most developing animal bodies;changes in the times and places they are expressed can lead to phenotypic variation. 
D) Greater numbers of genes in an animal's genome produce a wider variety of morphological structures and patterns. 
A) Genetic mutations are not as important in evolutionary change as the environment in which the organism develops. 
B) Changes in cell-cell interactions in a parent's body can lead to phenotypic change in offspring. 
C) Similar genes are found in most developing animal bodies;changes in the times and places they are expressed can lead to phenotypic variation. 
D) Greater numbers of genes in an animal's genome produce a wider variety of morphological structures and patterns.

Exam 21: Principles of Development

Which observation below provides evidence that differentiated cells retain all the genes of developing cells?

Cloning of plants from cuttings demonstrates that _____.

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

Modern cloning techniques have demonstrated that the vast majority of differentiated cells are genetically equivalent to developing cells in the embryo.What example below is an exception to this finding?

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

Many different lineages of animals share similar pattern-formation gene complexes.The study of how these shared complexes function in evolution is termed _____.

What is common to gap genes,segment-polarity genes,and homeotic genes?

Suppose you found several Drosophila mutants that possessed additional legs growing out of their head segments.The probable mutation would be found in _____.

In snake populations,rare individuals are found that have well-developed hind limbs,but are normal in all other respects.These unusual snakes suggest that _____.

Gene expression in developing organisms is regulated on several different levels.In many developing animals,regulation of gene expression is influenced by the action of Hox genes.Which of the following regulatory elements is produced by many Hox genes?

The predominant mechanism driving cellular differentiation is the difference in gene _____.

All of the following characteristics are shared between plant and animal development except:

Programmed cell death,apoptosis,plays a major role in all of the following developmental situations except: _____.

Suppose there was a mutation in the segment-polarity genes of Drosophila.What do you suppose might be the outcome?

Communication within and between cells of an embryo can include all of the following except _____.

Scientists have found that the lifetimes of mRNAs coding for pair-rule regulatory elements in Drosophila embryos may be measured in minutes.What does this suggest about the overall developmental plan of an animal body?

All of the following are true of embryonic stem cells except _____.

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

In combination,what do the products of gap genes,pair-rule genes,and segmentation polarity genes of fruit flies do?

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

Meiosis

Mendel and the Gene

Dna and the Gene: Synthesis and Repair

How Genes Work

Transcription and Translation

Control of Gene Expression in Bacteria

Control of Gene Expression in Eukaryotes

Analyzing and Engineering Genes

Genomics

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 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

Behavioral Ecology

Population Ecology

Community Ecology

Ecosystems

Biodiversity and Conservation Biology

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