Question 1

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

Accepted Answer

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

Question 2

Which of the following human cells contains the gene for alcohol dehydrogenase,a liver enzyme that processes alcohol?

Accepted Answer

A) sperm and egg cells 
B) liver cells 
C) heart cells 
D) Only the cells in A and B contain the gene for this enzyme. 
E) All of the cells in A,B,and C contain the gene for this enzyme. 
A) sperm and egg cells 
B) liver cells 
C) heart cells 
D) Only the cells in A and B contain the gene for this enzyme. 
E) All of the cells in A,B,and C contain the gene for this enzyme.

Question 3

Individual organisms often get larger throughout their lifetime (up until a certain point).Which of the processes below plays a role in this gain in size?

Accepted Answer

A) meiosis 
B) mitosis 
C) fertilization 
D) budding 
A) meiosis 
B) mitosis 
C) fertilization 
D) budding

Question 4

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,rather than the ways in which they are regulated,lead to the development of more complex animals over time. 
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,rather than the ways in which they are regulated,lead to the development of more complex animals over time.

Question 5

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 6

Suppose you found several Drosophila mutants that possessed additional legs growing out of the 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 7

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

Accepted Answer

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

Question 8

The plant Veratrum californicum contains an alkaloid that can severely affect normal developmental processes.When pregnant ewes eat this plant,their lambs may suffer deformities such as cyclopia (the development of a single central eye)and limb abnormalities.Experiments have shown that in the presence of this alkaloid,a protein known as Sonic hedgehog does not diffuse into limb buds of the embryo.The alkaloid inhibits cholesterol synthesis.What do you think is the explanation for the alkaloid's effect on development?

Accepted Answer

A) The alkaloid blocks the transcription of Sonic hedgehog. 
B) The alkaloid cleaves Sonic hedgehog,making it ineffective. 
C) Cholesterol is needed for the diffusion of Sonic hedgehog into the limb bud. 
D) Cholesterol is needed for the translation of Sonic hedgehog mRNA. 
A) The alkaloid blocks the transcription of Sonic hedgehog. 
B) The alkaloid cleaves Sonic hedgehog,making it ineffective. 
C) Cholesterol is needed for the diffusion of Sonic hedgehog into the limb bud. 
D) Cholesterol is needed for the translation of Sonic hedgehog mRNA.

Question 9

Even though plant and animal development processes share a number of features,there are some differences between the two groups of organisms.Which of the following is NOT a shared characteristic of plant and animal development?

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 10

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

Accepted Answer

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

Question 11

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

Accepted Answer

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

Question 12

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

Accepted Answer

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

Question 13

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 14

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.

Question 15

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

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 16

When is a cell considered differentiated?

Accepted Answer

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

Question 17

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) 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 18

Which of the following is not an example of the process of apoptosis during organ and tissue development?

Accepted Answer

A) Death of cells between the toes in chicken embryos. 
B) Leaves falling off trees in the fall. 
C) Petals falling off flowers after pollination. 
D) Lou Gehrig's disease 
A) Death of cells between the toes in chicken embryos. 
B) Leaves falling off trees in the fall. 
C) Petals falling off flowers after pollination. 
D) Lou Gehrig's disease

Question 19

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.

Exam 21: Principles of Development

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

Which of the following human cells contains the gene for alcohol dehydrogenase,a liver enzyme that processes alcohol?

Individual organisms often get larger throughout their lifetime (up until a certain point).Which of the processes below plays a role in this gain in size?

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

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

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

Even though plant and animal development processes share a number of features,there are some differences between the two groups of organisms.Which of the following is NOT a shared characteristic of plant and animal development?

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

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

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

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?

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

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

When is a cell considered differentiated?

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?

Which of the following is not an example of the process of apoptosis during organ and tissue development?

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

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, RNA Processing, 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 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

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