Question 1

In multicellular organisms, the coordination of cellular activities relies on

Accepted Answer

A)  cell receptors that detect transcription factors. 
B)  the availability of certain "key" nutrients as cells divide. 
C)  operons. 
D)  cell-to-cell signaling and signal transduction pathways. 
A)  cell receptors that detect transcription factors. 
B)  the availability of certain "key" nutrients as cells divide. 
C)  operons. 
D)  cell-to-cell signaling and signal transduction pathways.

Question 2

While DNA microarrays can be used to determine whether or not a gene is expressed in a cell, quantitative polymerase chain reaction (qPCR) can be used to specifically quantify the extent of gene expression in cells and tissues. To perform qPCR, mRNA is extracted from cells and reverse transcribed to complementary DNA (cDNA). Using fluorescent DNA molecules that recognize specific gene sequences and DNA polymerase, copies of the gene sequence of interest are made. After the copies are made, a fluorescent detector measures the intensity of the fluorescent signal, which is proportional to the number of mRNA transcripts in the cell and corresponds to the level of gene expression in the cell.
-In a muscle cell, the contractile protein myosin is present in larger quantities than the structural protein actin. Which of the following qPCR results would support this observation?

Accepted Answer

A)  The fluorescent signal for myosin is higher than that of actin. 
B)  The fluorescent signal for actin is higher than that of myosin. 
C)  The fluorescent signals for myosin and actin are equal. 
D)  The fluorescent signal for myosin is large and is zero for actin. 
A)  The fluorescent signal for myosin is higher than that of actin. 
B)  The fluorescent signal for actin is higher than that of myosin. 
C)  The fluorescent signals for myosin and actin are equal. 
D)  The fluorescent signal for myosin is large and is zero for actin.

Question 3

Which statement regarding skin cells and muscle cells in your body is true?

Accepted Answer

A)  Muscle cells contain information about muscle proteins but not about skin color. 
B)  Skin cells contain information about skin color but not about muscle proteins. 
C)  Muscle cells contain information about skin color but not about muscle proteins. 
D)  Skin cells and muscle cells each contain information about both muscle proteins and skin color. 
A)  Muscle cells contain information about muscle proteins but not about skin color. 
B)  Skin cells contain information about skin color but not about muscle proteins. 
C)  Muscle cells contain information about skin color but not about muscle proteins. 
D)  Skin cells and muscle cells each contain information about both muscle proteins and skin color.

Question 4

Which statement about fruit fly development is false?

Accepted Answer

A)  One of the earliest development events is the determination of the head and tail ends of the egg. 
B)  The location of the head and tail ends of the egg is primarily determined by the location of sperm entry during fertilization. 
C)  Homeotic genes regulate batteries of other genes that direct the anatomical identity of body parts. 
D)  Cascades of gene expression routinely direct fruit fly development. 
A)  One of the earliest development events is the determination of the head and tail ends of the egg. 
B)  The location of the head and tail ends of the egg is primarily determined by the location of sperm entry during fertilization. 
C)  Homeotic genes regulate batteries of other genes that direct the anatomical identity of body parts. 
D)  Cascades of gene expression routinely direct fruit fly development.

Question 5

The cloning of Dolly the sheep

Accepted Answer

A)  demonstrated that the nuclei from differentiated mammalian cells can retain their full genetic potential. 
B)  demonstrated that differentiated cells contain only a fraction of their full genetic potential. 
C)  demonstrated, for the first time, that eggs are haploid and body cells are diploid. 
D)  revealed that cloned mammals most resemble the egg donor. 
A)  demonstrated that the nuclei from differentiated mammalian cells can retain their full genetic potential. 
B)  demonstrated that differentiated cells contain only a fraction of their full genetic potential. 
C)  demonstrated, for the first time, that eggs are haploid and body cells are diploid. 
D)  revealed that cloned mammals most resemble the egg donor.

Question 6

The major function of siRNAs is to

Accepted Answer

A)  increase the rate of protein translation. 
B)  turn off gene expression. 
C)  prevent chromatin condensation. 
D)  support DNA replication. 
A)  increase the rate of protein translation. 
B)  turn off gene expression. 
C)  prevent chromatin condensation. 
D)  support DNA replication.

Question 7

What is the correct order of structures in a chromosome from smallest to largest?

Accepted Answer

A)  nucleotide, nucleosome, histone, tight helical fiber, chromosome 
B)  nucleosome, nucleotide, histone, tight helical fiber, chromosome 
C)  nucleotide, histone, tight helical fiber, nucleosome, chromosome 
D)  nucleotide, histone, nucleosome, tight helical fiber, chromosome 
A)  nucleotide, nucleosome, histone, tight helical fiber, chromosome 
B)  nucleosome, nucleotide, histone, tight helical fiber, chromosome 
C)  nucleotide, histone, tight helical fiber, nucleosome, chromosome 
D)  nucleotide, histone, nucleosome, tight helical fiber, chromosome

Question 8

Which of the following statements regarding cancer risk factors is false?

Accepted Answer

A)  Factors that alter DNA and make cells cancerous are called carcinogens. 
B)  Mutagens are usually not carcinogens. 
C)  X-rays and ultraviolet radiation are two of the most potent carcinogens. 
D)  Eating 20-30 grams of plant fiber daily and reducing the intake of animal fat can reduce your risk of developing colon cancer. 
A)  Factors that alter DNA and make cells cancerous are called carcinogens. 
B)  Mutagens are usually not carcinogens. 
C)  X-rays and ultraviolet radiation are two of the most potent carcinogens. 
D)  Eating 20-30 grams of plant fiber daily and reducing the intake of animal fat can reduce your risk of developing colon cancer.

Question 9

There is a mutation in the operator of the trp operon in a cell such that the trp repressor is unable to bind to the operator. If tryptophan is added to the cell, what will happen?

Accepted Answer

A)  Tryptophan will bind to the repressor, and trp enzymes will be produced. 
B)  Tryptophan will bind to the repressor, and trp enzymes will not be produced. 
C)  Tryptophan will not bind to the repressor, and trp enzymes will be produced. 
D)  Tryptophan will bind to the operator, and trp enzymes will be produced. 
A)  Tryptophan will bind to the repressor, and trp enzymes will be produced. 
B)  Tryptophan will bind to the repressor, and trp enzymes will not be produced. 
C)  Tryptophan will not bind to the repressor, and trp enzymes will be produced. 
D)  Tryptophan will bind to the operator, and trp enzymes will be produced.

Question 10

Melanoma (skin cancer) can develop after several mutations occur in skin cells. If a woman is diagnosed with melanoma and becomes pregnant, what are the chances that her offspring will inherit melanoma?

Accepted Answer

A)  The offspring will certainly be born with melanoma. 
B)  There is a chance, but it depends on how serious the mother's melanoma is. 
C)  There is a chance, but it depends on whether or not the father has melanoma. 
D)  It is unlikely that the offspring will be born with melanoma. 
A)  The offspring will certainly be born with melanoma. 
B)  There is a chance, but it depends on how serious the mother's melanoma is. 
C)  There is a chance, but it depends on whether or not the father has melanoma. 
D)  It is unlikely that the offspring will be born with melanoma.

Question 11

Which statement about proto-oncogenes is false?

Accepted Answer

A)  Proto-oncogenes are normal genes with the potential to become oncogenes. 
B)  Many proto-oncogenes code for growth factors. 
C)  A mutation must occur in a cell's DNA for a proto-oncogene to become an oncogene. 
D)  If a proto-oncogene's gene product is produced in smaller quantities, a cell may become cancerous. 
A)  Proto-oncogenes are normal genes with the potential to become oncogenes. 
B)  Many proto-oncogenes code for growth factors. 
C)  A mutation must occur in a cell's DNA for a proto-oncogene to become an oncogene. 
D)  If a proto-oncogene's gene product is produced in smaller quantities, a cell may become cancerous.

Question 12

The lac operon in Escherichia coli

Accepted Answer

A)  prevents lactose-utilizing enzymes from being expressed when lactose is absent from the environment. 
B)  prevents lactose intolerance. 
C)  prevents lactose-utilizing enzymes from being expressed when lactose is present in the environment. 
D)  promotes the expression of lactose-utilizing enzymes when lactose is absent from the environment. 
A)  prevents lactose-utilizing enzymes from being expressed when lactose is absent from the environment. 
B)  prevents lactose intolerance. 
C)  prevents lactose-utilizing enzymes from being expressed when lactose is present in the environment. 
D)  promotes the expression of lactose-utilizing enzymes when lactose is absent from the environment.

Question 13

The tortoiseshell pattern on a cat

Accepted Answer

A)  usually occurs in males. 
B)  is the result of a homozygous recessive condition. 
C)  results from X chromosome inactivation. 
D)  is a result of alleles on the Y chromosome. 
A)  usually occurs in males. 
B)  is the result of a homozygous recessive condition. 
C)  results from X chromosome inactivation. 
D)  is a result of alleles on the Y chromosome.

Question 14

During an experiment assessing the development of a fly embryo, a scientist artificially turns on a homeotic gene that controls eye development in somatic cells that normally develop into the wings. Which of the following is the most likely outcome of this experiment?

Accepted Answer

A)  A normal adult fly will develop. 
B)  A mutant adult fly will develop that has eyes on its wings. 
C)  A mutant adult fly will develop that has legs on its head. 
D)  A mutant adult fly will develop that has no eyes on its head but has eyes on its wings. 
A)  A normal adult fly will develop. 
B)  A mutant adult fly will develop that has eyes on its wings. 
C)  A mutant adult fly will develop that has legs on its head. 
D)  A mutant adult fly will develop that has no eyes on its head but has eyes on its wings.

Question 15

Half the trees in an orchard were derived from rootstock "A" and half from rootstock "B," but all the trees had the same scion. If the trees grafted onto rootstock "A" were infected by a parasite that causes blossom rot, the trees grafted onto rootstock "B"

Accepted Answer

A)  would be less likely to become infected because they're grafted onto different rootstocks. 
B)  would be more likely to become infected, since the pathogen would spread through the soil to the roots of other trees. 
C)  would be very likely to become infected, because the remaining scions are genetically identical to those that are already infected. 
D)  There's no way to determine the likelihood of infection, since genetic variability gives all the trees different characteristics. 
A)  would be less likely to become infected because they're grafted onto different rootstocks. 
B)  would be more likely to become infected, since the pathogen would spread through the soil to the roots of other trees. 
C)  would be very likely to become infected, because the remaining scions are genetically identical to those that are already infected. 
D)  There's no way to determine the likelihood of infection, since genetic variability gives all the trees different characteristics.

Question 16

A stomach cell is producing pepsin, an enzyme that hydrolyzes proteins. Which of the following events suggests that gene expression of pepsin has been turned off in the cell?

Accepted Answer

A)  The pepsin protein is folded properly in the cytoplasm. 
B)  The chromosome with the pepsin gene is tightly coiled. 
C)  The pepsin mRNA leaves the nucleus and enters the cytoplasm. 
D)  Activators and RNA polymerases are abundant in the nucleus. 
A)  The pepsin protein is folded properly in the cytoplasm. 
B)  The chromosome with the pepsin gene is tightly coiled. 
C)  The pepsin mRNA leaves the nucleus and enters the cytoplasm. 
D)  Activators and RNA polymerases are abundant in the nucleus.

Question 17

The genes for the enzymes of glycolysis

Accepted Answer

A)  are present in all metabolizing cells, but the genes for specialized proteins are expressed only in particular cell types. 
B)  are present in all metabolizing cells, and the genes for specialized proteins are expressed in all cell types. 
C)  and the genes for all specialized proteins are expressed in all metabolizing cells. 
D)  and the genes for all specialized proteins are expressed in all embryonic cells. 
A)  are present in all metabolizing cells, but the genes for specialized proteins are expressed only in particular cell types. 
B)  are present in all metabolizing cells, and the genes for specialized proteins are expressed in all cell types. 
C)  and the genes for all specialized proteins are expressed in all metabolizing cells. 
D)  and the genes for all specialized proteins are expressed in all embryonic cells.

Question 18

A homeotic gene

Accepted Answer

A)  determines which end of the egg will become the head and which end will become the tail. 
B)  serves as a master control gene that functions during embryonic development by controlling the developmental fate of groups of cells. 
C)  represses gene transcription and promotes mRNA translation. 
D)  is found only in adult somatic cells. 
A)  determines which end of the egg will become the head and which end will become the tail. 
B)  serves as a master control gene that functions during embryonic development by controlling the developmental fate of groups of cells. 
C)  represses gene transcription and promotes mRNA translation. 
D)  is found only in adult somatic cells.

Question 19

Gene knockdown is a procedure used to reduce gene expression in cells or organisms so that scientists can investigate gene function. While there are several ways to knock down gene expression, RNAi is one of the most commonly used approaches. Suppose that a research team wants to investigate where a new gene X is expressed in the fruit fly, Drosophila melanogaster. Using RNAi, they obtained the results shown below examining the expression of gene X in four types of tissues.
-Which of the following physiological results would you possibly find in the Drosophila that underwent RNAi against gene X?

Accepted Answer

A)  The flies would not be able to fly as well because their flight muscles have been affected. 
B)  The flies would not be able to see as well because their neurons have been affected. 
C)  The flies would not be able to digest food as well because their epithelial tissues have been affected. 
D)  The flies would not be able to produce collagen because their connective tissues have been affected. 
A)  The flies would not be able to fly as well because their flight muscles have been affected. 
B)  The flies would not be able to see as well because their neurons have been affected. 
C)  The flies would not be able to digest food as well because their epithelial tissues have been affected. 
D)  The flies would not be able to produce collagen because their connective tissues have been affected.

Question 20

Which structure in this figure shows one complete nucleosome?

Accepted Answer

A)  structure A 
B)  structure B 
C)  structure C 
D)  structure D 
A)  structure A 
B)  structure B 
C)  structure C 
D)  structure D

Exam 11: How Genes Are Controlled

In multicellular organisms, the coordination of cellular activities relies on

Which statement regarding skin cells and muscle cells in your body is true?

Which statement about fruit fly development is false?

The cloning of Dolly the sheep

The major function of siRNAs is to

What is the correct order of structures in a chromosome from smallest to largest?

Which of the following statements regarding cancer risk factors is false?

There is a mutation in the operator of the trp operon in a cell such that the trp repressor is unable to bind to the operator. If tryptophan is added to the cell, what will happen?

Melanoma (skin cancer) can develop after several mutations occur in skin cells. If a woman is diagnosed with melanoma and becomes pregnant, what are the chances that her offspring will inherit melanoma?

Which statement about proto-oncogenes is false?

The lac operon in Escherichia coli

The tortoiseshell pattern on a cat

During an experiment assessing the development of a fly embryo, a scientist artificially turns on a homeotic gene that controls eye development in somatic cells that normally develop into the wings. Which of the following is the most likely outcome of this experiment?

Half the trees in an orchard were derived from rootstock "A" and half from rootstock "B," but all the trees had the same scion. If the trees grafted onto rootstock "A" were infected by a parasite that causes blossom rot, the trees grafted onto rootstock "B"

A stomach cell is producing pepsin, an enzyme that hydrolyzes proteins. Which of the following events suggests that gene expression of pepsin has been turned off in the cell?

The genes for the enzymes of glycolysis

A homeotic gene

Which structure in this figure shows one complete nucleosome?

Biology: Exploring Life

The Chemical Basis of Life

The Molecules of Cells

A Tour of the Cell

The Working Cell

How Cells Harvest Chemical Energy

Photosynthesis: Using Light to Make Food

The Cellular Basis of Reproduction and Inheritance

Patterns of Inheritance

Molecular Biology of the Gene

DNA Technology and Genomics

How Populations Evolve

The Origin of Species

Tracing Evolutionary History

Microbial Life: Prokaryotes and Protists

The Evolution of Plant and Fungal Diversity

The Evolution of Invertebrate Diversity

The Evolution of Vertebrate Diversity

Unifying Concepts of Animal Structure and Function

Nutrition and Digestion

Gas Exchange

Circulation

The Immune System

Control of Body Temperature and Water Balance

Hormones and the Endocrine System

Reproduction and Embryonic Development

Nervous Systems

The Senses

How Animals Move

Plant Structure, Growth, and Reproduction

Plant Nutrition and Transport

Control Systems in Plants

The Biosphere: an Introduction to Earths Diverse Environments

Behavioral Adaptations to the Environment

Population Ecology

Communities and Ecosystems

Conservation Biology

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