Question 1

Which of the following statements is true of embryonic stem cells?

Accepted Answer

A) They normally differentiate into only eggs and sperm. 
B) They can give rise to all cell types in the organism. 
C) They can continue to reproduce for an indefinite period. 
D) They can provide enormous amounts of information about the process of gene regulation. 
A) They normally differentiate into only eggs and sperm. 
B) They can give rise to all cell types in the organism. 
C) They can continue to reproduce for an indefinite period. 
D) They can provide enormous amounts of information about the process of gene regulation. B

Question 2

Proto-oncogenes can change into oncogenes that cause cancer.Which of the following best explains the presence of these potential time bombs in eukaryotic cells?

Accepted Answer

A) Proto-oncogenes first arose from viral infections. 
B) Proto-oncogenes are mutant versions of normal genes. 
C) Proto-oncogenes are genetic "junk." 
D) Proto-oncogenes normally help regulate cell division. 
A) Proto-oncogenes first arose from viral infections. 
B) Proto-oncogenes are mutant versions of normal genes. 
C) Proto-oncogenes are genetic "junk." 
D) Proto-oncogenes normally help regulate cell division. D

Question 3

Cell differentiation always involves

Accepted Answer

A) the transcription of the myoD gene. 
B) the movement of cells. 
C) the production of tissue-specific proteins. 
D) the selective loss of certain genes from the genome. 
A) the transcription of the myoD gene. 
B) the movement of cells. 
C) the production of tissue-specific proteins. 
D) the selective loss of certain genes from the genome. A

Question 4

In colorectal cancer,several genes must be mutated in order to contribute to a cell developing into a cancer cell.Which of the following kinds of genes would you expect to be mutated?

Accepted Answer

A) genes coding for enzymes that act in the colon 
B) genes involved in control of the cell cycle 
C) genes that are especially susceptible to mutation 
D) BRCA1 and BRCA2 
A) genes coding for enzymes that act in the colon 
B) genes involved in control of the cell cycle 
C) genes that are especially susceptible to mutation 
D) BRCA1 and BRCA2

Question 5

Apoptosis involves all but which of the following?

Accepted Answer

A) fragmentation of the DNA 
B) cell-signaling pathways 
C) lysis of the cell 
D) digestion of cellular contents by scavenger cells 
A) fragmentation of the DNA 
B) cell-signaling pathways 
C) lysis of the cell 
D) digestion of cellular contents by scavenger cells

Question 6

Cloned animals often die prematurely.Which of the following processes explains why this can occur?

Accepted Answer

A) use of pluripotent instead of totipotent stem cells 
B) abnormal gene regulation due to variant methylation 
C) the indefinite replication of totipotent stem cells 
D) abnormal immune function due to bone marrow dysfunction 
A) use of pluripotent instead of totipotent stem cells 
B) abnormal gene regulation due to variant methylation 
C) the indefinite replication of totipotent stem cells 
D) abnormal immune function due to bone marrow dysfunction

Question 7

Which of the following processes would result from a mutation in the ras gene?

Accepted Answer

A) activation of protein kinases 
B) DNA replication 
C) DNA repair 
D) activation of apoptosis 
A) activation of protein kinases 
B) DNA replication 
C) DNA repair 
D) activation of apoptosis

Question 8

Pax-6 is a gene that is involved in eye formation in many invertebrates,such as Drosophila.Pax-6 is also found in vertebrates.A Pax-6 gene from a mouse can be expressed in a fly,and the protein (PAX-6)leads to a compound fly eye.This information suggests which of the following?

Accepted Answer

A) Pax-6 genes are identical in nucleotide sequence. 
B) PAX-6 proteins have identical amino acid sequences. 
C) Pax-6 is highly conserved and shows shared evolutionary ancestry. 
D) PAX-6 proteins are different for formation of different kinds of eyes. 
A) Pax-6 genes are identical in nucleotide sequence. 
B) PAX-6 proteins have identical amino acid sequences. 
C) Pax-6 is highly conserved and shows shared evolutionary ancestry. 
D) PAX-6 proteins are different for formation of different kinds of eyes.

Question 9

Absence of bicoid mRNA from a Drosophila egg leads to the absence of anterior larval body parts and mirror-image duplication of posterior parts.This is evidence that the product of the bicoid gene

Accepted Answer

A) normally leads to formation of head structures. 
B) normally leads to formation of tail structures. 
C) is transcribed in the early embryo. 
D) is a protein present in all head structures. 
A) normally leads to formation of head structures. 
B) normally leads to formation of tail structures. 
C) is transcribed in the early embryo. 
D) is a protein present in all head structures.

Question 10

The first cloned cat,called Carbon Copy,was a calico,but she looked significantly different from her female parent.Why?

Accepted Answer

A) The environment,as well as genetics,affects phenotypic variation. 
B) Fur color genes in cats are influenced by differential acetylation patterns. 
C) Cloned animals have been found to have a higher frequency of transposon activation. 
D) X chromosome inactivation in the embryo is random and produces different patterns in each individual. 
A) The environment,as well as genetics,affects phenotypic variation. 
B) Fur color genes in cats are influenced by differential acetylation patterns. 
C) Cloned animals have been found to have a higher frequency of transposon activation. 
D) X chromosome inactivation in the embryo is random and produces different patterns in each individual.

Question 11

Which of the following statements is a likely explanation for why therapeutic cloning is considered acceptable by many?

Accepted Answer

A) Use of adult stem cells is likely to produce more cell types than use of embryonic stem cells. 
B) Cloning to produce embryonic stem cells may lead to treatments for a large number of diseases. 
C) Cloning to produce stem cells relies on a different initial procedure than reproductive cloning. 
D) A clone that lives until the blastocyst stage does not yet have human DNA. 
A) Use of adult stem cells is likely to produce more cell types than use of embryonic stem cells. 
B) Cloning to produce embryonic stem cells may lead to treatments for a large number of diseases. 
C) Cloning to produce stem cells relies on a different initial procedure than reproductive cloning. 
D) A clone that lives until the blastocyst stage does not yet have human DNA.

Question 12

If a lethal mutation occurs in an embryo,what might be the result?

Accepted Answer

A) phenotypes that prevent fertilization 
B) failure to express maternal effect genes 
C) death during development 
D) phenotypes that are never born/hatched 
A) phenotypes that prevent fertilization 
B) failure to express maternal effect genes 
C) death during development 
D) phenotypes that are never born/hatched

Question 13

Your brother has just purchased a new plastic model airplane.He places all the parts on the table in approximately the positions in which they will be located when the model is complete.Which process in development do these actions compare to?

Accepted Answer

A) morphogenesis 
B) determination 
C) induction 
D) pattern formation 
A) morphogenesis 
B) determination 
C) induction 
D) pattern formation

Question 14

Which of the following events is considered to be the first evidence of differentiation in the cells of an embryo?

Accepted Answer

A) cell division occurring after fertilization 
B) the occurrence of mRNAs for the production of tissue-specific proteins 
C) determination of specific cells for certain functions 
D) changes in the size and shape of the cell 
A) cell division occurring after fertilization 
B) the occurrence of mRNAs for the production of tissue-specific proteins 
C) determination of specific cells for certain functions 
D) changes in the size and shape of the cell

Question 15

Muscle cells differ from nerve cells mainly because they

Accepted Answer

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

Question 16

Which of the following statements correctly describes one of the differences between embryonic and adult stem cells in animals?

Accepted Answer

A) Embryonic stem cells can differentiate into more cell types than adult stem cells. 
B) Adult stem cells can differentiate into more cell types than embryonic stem cells. 
C) Embryonic stem cells have fewer genes than adult stem cells. 
D) Embryonic stem cells are localized to specific sites within the embryo,whereas adult stem cells are spread throughout the body. 
A) Embryonic stem cells can differentiate into more cell types than adult stem cells. 
B) Adult stem cells can differentiate into more cell types than embryonic stem cells. 
C) Embryonic stem cells have fewer genes than adult stem cells. 
D) Embryonic stem cells are localized to specific sites within the embryo,whereas adult stem cells are spread throughout the body.

Question 17

Forms of the p53 protein found in tumors usually cause which of the following?

Accepted Answer

A) activation of DNA repair 
B) activation of apoptosis 
C) cell division to stop 
D) excessive cell growth 
A) activation of DNA repair 
B) activation of apoptosis 
C) cell division to stop 
D) excessive cell growth

Question 18

Which of the following processes must be performed on adult somatic cells in order to induce them to become pluripotent stem cells?

Accepted Answer

A) A retrovirus is used to introduce four master regulatory genes. 
B) The adult stem cells are fused with embryonic cells. 
C) Cytoplasm from embryonic cells is injected into the adult cells. 
D) The nucleus of an embryonic cell is used to replace the nucleus of an adult cell. 
A) A retrovirus is used to introduce four master regulatory genes. 
B) The adult stem cells are fused with embryonic cells. 
C) Cytoplasm from embryonic cells is injected into the adult cells. 
D) The nucleus of an embryonic cell is used to replace the nucleus of an adult cell.

Question 19

A researcher is using adult stem cells and comparing them to other adult cells from the same tissue.Which of the following statements describes a likely finding of this research?

Accepted Answer

A) The cells from the two sources exhibit different patterns of DNA methylation. 
B) Adult stem cells have more DNA nucleotides than their counterparts. 
C) The two kinds of cells have virtually identical gene expression patterns in microarrays. 
D) The non-stem cells have fewer repressed genes. 
A) The cells from the two sources exhibit different patterns of DNA methylation. 
B) Adult stem cells have more DNA nucleotides than their counterparts. 
C) The two kinds of cells have virtually identical gene expression patterns in microarrays. 
D) The non-stem cells have fewer repressed genes.

Question 20

Why are the BRCA1 and BRCA2 genes considered to be tumor-suppressor genes?

Accepted Answer

A) They prevent infection by tumor viruses that cause cancer. 
B) Their normal products participate in repair of DNA damage. 
C) The mutant forms of either one of these prevent breast cancer. 
D) They block penetration of breast cells by chemical carcinogens. 
A) They prevent infection by tumor viruses that cause cancer. 
B) Their normal products participate in repair of DNA damage. 
C) The mutant forms of either one of these prevent breast cancer. 
D) They block penetration of breast cells by chemical carcinogens.

Exam 16: Development,stem Cells,and Cancer

Which of the following statements is true of embryonic stem cells?

Proto-oncogenes can change into oncogenes that cause cancer.Which of the following best explains the presence of these potential time bombs in eukaryotic cells?

Cell differentiation always involves

In colorectal cancer,several genes must be mutated in order to contribute to a cell developing into a cancer cell.Which of the following kinds of genes would you expect to be mutated?

Apoptosis involves all but which of the following?

Cloned animals often die prematurely.Which of the following processes explains why this can occur?

Which of the following processes would result from a mutation in the ras gene?

Pax-6 is a gene that is involved in eye formation in many invertebrates,such as Drosophila.Pax-6 is also found in vertebrates.A Pax-6 gene from a mouse can be expressed in a fly,and the protein (PAX-6)leads to a compound fly eye.This information suggests which of the following?

Absence of bicoid mRNA from a Drosophila egg leads to the absence of anterior larval body parts and mirror-image duplication of posterior parts.This is evidence that the product of the bicoid gene

The first cloned cat,called Carbon Copy,was a calico,but she looked significantly different from her female parent.Why?

Which of the following statements is a likely explanation for why therapeutic cloning is considered acceptable by many?

If a lethal mutation occurs in an embryo,what might be the result?

Your brother has just purchased a new plastic model airplane.He places all the parts on the table in approximately the positions in which they will be located when the model is complete.Which process in development do these actions compare to?

Which of the following events is considered to be the first evidence of differentiation in the cells of an embryo?

Muscle cells differ from nerve cells mainly because they

Which of the following statements correctly describes one of the differences between embryonic and adult stem cells in animals?

Forms of the p53 protein found in tumors usually cause which of the following?

Which of the following processes must be performed on adult somatic cells in order to induce them to become pluripotent stem cells?

A researcher is using adult stem cells and comparing them to other adult cells from the same tissue.Which of the following statements describes a likely finding of this research?

Why are the BRCA1 and BRCA2 genes considered to be tumor-suppressor genes?

Introduction: Evolution and the Foundations of Biology

The Chemical Context of Life

Carbon and the Molecular Diversity of Life

A Tour of the Cell

Membrane Transport and Cell Signaling

An Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

Gene Expression: From Gene to Protein

Regulation of Gene Expression

Viruses

Genomes and Their Evolution

Descent With Modification

Phylogeny

The Evolution of Populations

The Origin of Species

Broad Patterns of Evolution

Early Life and the Diversification of Prokaryotes

The Origin and Diversification of Eukaryotes

The Colonization of Land by Plants and Fungi

The Rise of Animal Diversity

Plant Structure and Growth

Resource Acquisition,nutrition,and Transport in Vascular Plants

Reproduction and Domestication of Flowering Plants

Plant Responses to Internal and External Signals

Homeostasis and Endocrine Signaling

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Reproduction and Development

Neurons,synapses,and Signaling

Nervous and Sensory Systems

Motor Mechanisms and Behavior

Population Ecology and the Distribution of Organisms

Ecological Communities

Ecosystems and Energy

Conservation Biology and Global Change

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