p.9
Discovery of Genes and Alleles
What is chromosome mapping?
Localizing genes to specific positions within chromosomes.
p.9
Structure and Function of DNA
What marked the beginning of molecular genetics?
The discovery of the structure of DNA.
p.7
Gene Expression: Transcription and Translation
What is the central dogma of molecular biology?
The flow of information from DNA to RNA to polypeptide.
p.7
DNA Replication and Mutation
What can cause mutations in DNA?
Incorrect incorporation of nucleotides during DNA replication, electromagnetic radiation, or chemicals.
p.10
Applications of Genetics in Agriculture
How did early humans apply genetic principles before Mendel?
By selectively breeding crops and livestock to improve them.
p.7
DNA Replication and Mutation
How does the mutation in the β-globin gene affect red blood cells?
It causes red blood cells to become sickle-shaped, which impairs their ability to transport oxygen efficiently.
p.9
Population Genetics and Evolution
What does evolution depend on?
The occurrence, transmission, and spread of mutant genes in groups of organisms.
p.10
Molecular Genetics and Genetic Engineering
What is the molecular approach to genetic analysis?
It involves studying DNA sequences, cutting DNA molecules at specific sites, and manipulating genes by excising and inserting them into other DNA molecules.
p.7
Gene Expression: Transcription and Translation
Which virus uses reverse transcription and affects the human genome?
The virus that causes acquired immune deficiency syndrome (AIDS).
p.7
Gene Expression: Transcription and Translation
What is reverse transcription?
The process where RNA is used as a template for the synthesis of DNA.
p.4
Structure and Function of DNA
What are the three essential functions of DNA?
Replication, information storage, and the ability to change.
p.3
The Human Genome Project
What is genomics?
The study of genes at the molecular level, made possible by advances in DNA sequencing technology, robotics, and computer science.
p.6
Gene Expression: Transcription and Translation
What is proteomics?
The study of all the proteins in cells, including their composition, amino acid sequences, interactions among polypeptides and proteins, and their functions.
p.11
Molecular Genetics and Genetic Engineering
How did molecular genetics supplement classical approaches to crop and livestock improvement in the 1980s?
Molecular genetics provided detailed genetic maps of chromosomes to pinpoint genes of agricultural significance, allowing breeders to design schemes to incorporate particular alleles into agricultural varieties.
p.11
Molecular Genetics and Genetic Engineering
What techniques are used to introduce genes from other species into crop plants and livestock?
Techniques of molecular genetics are used to introduce genes from other species, initially developed using test species like fruit flies.
p.8
Gene Expression: Transcription and Translation
How is genetic information expressed?
One strand of a gene’s DNA duplex is used as a template for the synthesis of a complementary strand of RNA.
p.11
Applications of Genetics in Agriculture
What role does selective breeding play in agriculture?
Selective breeding programs, informed by genetic theory, are used to develop high-yielding varieties of crops and improve livestock.
p.6
Gene Expression: Transcription and Translation
What initiates and terminates translation?
Translation is initiated by a start codon, which specifies the incorporation of methionine, and terminated by a stop codon, which does not specify the incorporation of any amino acid.
p.8
Population Genetics and Evolution
Why is the mutant β-globin gene relatively common in some human populations?
People who carry both a mutant and a nonmutant allele of this gene are less susceptible to malaria, leading to enhanced survival and more offspring.
p.4
Structure and Function of DNA
Which base pairs are held together by hydrogen bonds in DNA?
A pairs with T, and G pairs with C.
p.9
Population Genetics and Evolution
What program combines anatomical data from living and fossilized organisms to discern evolutionary relationships among species?
The 'Tree of Life' program.
p.3
The Human Genome Project
How many genes were initially estimated to be in the human genome?
Between 30,000 and 40,000 genes.
p.3
The Human Genome Project
What is the focus of current efforts in human genome research?
Studying how genes influence human characteristics and assessing genetic variability among humans.
p.2
Structure and Function of DNA
What are the base-pairing rules in DNA?
A pairs with T, and G pairs with C.
p.2
Structure and Function of DNA
How does RNA differ from DNA in terms of structure?
RNA molecules are usually single-stranded, while DNA is double-stranded.
p.6
Gene Expression: Transcription and Translation
What advances have made proteomics possible?
Advances in technologies used to study genes and gene products, and the development of computer programs to search databases and analyze amino acid sequences.
p.10
Population Genetics and Evolution
What is population genetics?
The study of genetic variability within a population and the frequencies of specific alleles over time.
p.10
Genetics in Medicine and Genetic Counseling
How is genetics relevant outside the research laboratory?
It has applications in agriculture, medicine, and many other human endeavors worldwide.
p.7
DNA Replication and Mutation
What amino acid change occurs in the β-globin polypeptide due to the sickle-cell mutation?
The sixth codon changes from specifying glutamic acid to specifying valine.
p.2
Structure and Function of DNA
Who deduced the organization of nucleotides within DNA in 1953?
James Watson and Francis Crick.
p.5
Gene Expression: Transcription and Translation
What are genes?
Genes are units of coding information within DNA that contain instructions for the synthesis of proteins.
p.8
Population Genetics and Evolution
How do researchers use DNA sequencing to study evolution?
Researchers compare DNA sequences to establish historical relationships among organisms, determining their descent from common ancestors.
p.10
Molecular Genetics and Genetic Engineering
What are recombinant DNA molecules?
DNA molecules that have been created by inserting genes or pieces of genes from one DNA molecule into another.
p.11
Molecular Genetics and Genetic Engineering
What are GMOs and give an example?
GMOs are genetically modified organisms that have been altered by the introduction of foreign genes. An example is BT corn, which carries a gene from the bacterium Bacillus thuringiensis.
p.3
The Human Genome Project
What was the Human Genome Project's main achievement in 2001?
The sequencing of 2.7 billion nucleotide pairs of human DNA.
p.8
DNA Replication and Mutation
How do mutations contribute to biological evolution?
Mutations can alter the DNA sequence of a gene, creating genetic variability that is the basis for biological evolution.
p.2
Structure and Function of DNA
What forms the backbone of a DNA chain?
A phosphate-sugar backbone.
p.5
Structure and Function of DNA
What is the difference between coding and noncoding DNA in humans?
Most of the DNA in humans is noncoding, meaning it does not contain genes that code for proteins.
p.5
Gene Expression: Transcription and Translation
What is the role of mRNA in gene expression?
mRNA contains all the information needed for the synthesis of a polypeptide and acts as a template during translation.
p.11
Applications of Genetics in Agriculture
How have cattle and corn changed from their wild ancestors?
Cattle have changed in appearance and behavior, while corn, descended from teosinte, has been altered so much that it can no longer grow without human cultivation.
p.10
Molecular Genetics and Genetic Engineering
What is the significance of being able to manipulate genes?
It allows researchers to study genetic phenomena in great detail and transfer genes from one organism to another.
p.10
Molecular Genetics and Genetic Engineering
What are the three main approaches to genetic analysis mentioned?
Classical genetic analysis, molecular genetic analysis, and population genetic analysis.
p.4
DNA Replication and Mutation
How are new DNA strands assembled during replication?
By the stepwise incorporation of nucleotides opposite to nucleotides in the template strands, following base-pairing rules.
p.8
Population Genetics and Evolution
What did Charles Darwin and Alfred Wallace propose about species variation?
They proposed that genetic variation makes it possible for species to evolve over time.
p.8
Population Genetics and Evolution
What is a phylogenetic tree?
A phylogenetic tree, or phylogeny, shows the evolutionary relationships among organisms based on similarities and differences in their DNA sequences.
p.9
Gregor Mendel's Research on Inheritance
What is transmission genetics?
The study of the transmission of genes and chromosomes from one generation to the next.
p.12
Molecular Genetics and Genetic Engineering
How has genetic engineering impacted the production of human growth hormone?
Human growth hormone, previously isolated from cadavers, is now manufactured in bacterial cells, providing a reliable source for treating children who cannot produce it naturally.
p.11
Applications of Genetics in Agriculture
What are some examples of plants and animals improved through selective breeding?
Examples include wheat, corn, rice, beef and dairy cattle, swine, sheep, shade trees, turf grass, and garden flowers.
p.7
Gene Expression: Transcription and Translation
Do all genes encode polypeptides?
No, many genes encode RNA molecules that play important roles within cells.
p.4
DNA Replication and Mutation
What ensures the faithful transmission of genetic material during DNA replication?
The complementary nature of the strands in duplex DNA molecules.
p.2
Structure and Function of DNA
What are the four kinds of bases in DNA?
Adenine (A), Guanine (G), Cytosine (C), and Thymine (T).
p.4
DNA Replication and Mutation
What is the result of the DNA replication process?
Two identical DNA duplexes are created from one original duplex.
p.8
Gregor Mendel's Research on Inheritance
How did Mendel’s discoveries influence research on biological evolution?
Mendel’s discoveries stimulated research on biological evolution and took a new turn with the emergence of DNA sequencing techniques.
p.12
Applications of Genetics in Agriculture
What is Bacillus thuringiensis (BT) and its significance in agriculture?
Bacillus thuringiensis is a bacterium whose gene encodes a protein toxic to many insects. Corn strains carrying the BT toxin gene are resistant to attacks by the European corn borer.
p.1
Gregor Mendel's Research on Inheritance
What did Mendel postulate from his research on pea plants?
Mendel postulated the existence of hereditary factors, now known as genes, responsible for the traits he studied.
p.6
Gene Expression: Transcription and Translation
What is the role of mRNA in protein synthesis?
mRNA serves as a template to synthesize polypeptides during translation.
p.7
DNA Replication and Mutation
What is a mutation?
A change in the DNA sequence that can alter or disrupt the information encoded in genes.
p.4
DNA Replication and Mutation
What serves as templates for the synthesis of new DNA strands during replication?
The separated strands of the original DNA molecule.
p.2
Structure and Function of DNA
How are the two strands of a DNA duplex configured?
They are wound around each other in a helical configuration.
p.5
Gene Expression: Transcription and Translation
What are codons?
Codons are triplets of adjacent nucleotides within a gene that specify the incorporation of an amino acid into a polypeptide.
p.12
Genetics in Medicine and Genetic Counseling
What role do genetic counselors play in medicine?
Genetic counselors are trained to advise people about the risks of inheriting or transmitting genetic diseases, helping to diagnose genetic diseases, trace them through families, and predict inheritance probabilities.
p.1
Gregor Mendel's Research on Inheritance
How many copies of each gene do pea plants carry according to Mendel?
Pea plants carry two copies of each gene, which may be the same or different.
p.6
Gene Expression: Transcription and Translation
What is the flow of information from genes to proteins?
Information flows from genes composed of DNA to polypeptides composed of amino acids through transcription and translation.
p.6
Gene Expression: Transcription and Translation
What happens to the initial methionine after translation is completed?
The initial methionine is removed to produce the mature β-globin polypeptide.
p.2
Structure and Function of DNA
Which bases are shared by both DNA and RNA?
Adenine (A), Guanine (G), and Cytosine (C).
p.9
Population Genetics and Evolution
How can DNA sequence data be used in the study of evolution?
DNA sequence data provide a way of studying the historical process of evolution.
p.4
Gene Expression: Transcription and Translation
What is the flow of information in biology?
From DNA to RNA to protein.
p.3
The Human Genome Project
What types of organisms have had their genomes sequenced under the Human Genome Project?
Bacteria, fungi, plants, protists, and animals.
p.3
Structure and Function of DNA
What did James Watson and Francis Crick elucidate?
The structure of DNA, a macromolecule composed of two complementary chains of nucleotides.
p.3
Discovery of Genes and Alleles
What are alleles?
Alternate forms of genes that account for heritable differences among individuals.
p.5
Gene Expression: Transcription and Translation
What is a proteome?
A proteome is the collection of all the different proteins in an organism.
p.1
Gregor Mendel's Research on Inheritance
When were Mendel's discoveries published and when did they gain recognition?
Mendel's discoveries were published in 1866 but gained recognition in 1900, 16 years after his death.
p.10
Molecular Genetics and Genetic Engineering
How can geneticists replicate recombinant DNA molecules?
By using bacterial cells or test tubes supplied with appropriate enzymes.
p.10
Population Genetics and Evolution
Why is the assessment of genetic variability in a population important?
It is foundational for studying biological evolution and understanding the inheritance of complex traits.
p.7
DNA Replication and Mutation
What is the consequence of a mutation in the β-globin gene?
It can cause sickle-cell disease by altering the shape of red blood cells, making them less efficient at transporting oxygen.
p.5
Structure and Function of DNA
How many nucleotide pairs are in the human genome?
3.2 billion nucleotide pairs.
p.8
Population Genetics and Evolution
What does the phylogenetic tree in Figure 1.10 illustrate?
It shows the evolutionary relationships among 11 different vertebrates based on the sequences of the gene for cytochrome b.
p.1
Discovery of Genes and Alleles
What are alleles according to Mendel's discoveries?
Alleles are different forms of a gene that Mendel discovered, such as those determining plant height or flower color.
p.6
Gene Expression: Transcription and Translation
Why is the human proteome larger than the number of genes in the human genome?
Because a single gene can encode several different polypeptides, and proteins can be produced by combining polypeptides encoded by different genes.
p.11
Molecular Genetics and Genetic Engineering
What is the significance of genome sequencing projects in agriculture?
Genome sequencing projects help identify and study potentially useful genes, aiding in the improvement of crop and livestock varieties.
p.4
DNA Replication and Mutation
How is genetic material transmitted during cell division and reproduction?
Through the replication of double-stranded DNA molecules.
p.8
DNA Replication and Mutation
What role does DNA replication play in genetics?
Each strand of a duplex molecule serves as the template for the synthesis of a complementary strand.
p.5
Structure and Function of DNA
What is the smallest known genome among cellular organisms?
The genome of Mycoplasma genitalium, which has 580,070 nucleotide pairs.
p.9
Molecular Genetics and Genetic Engineering
From which perspectives do geneticists approach their science?
From that of a gene, a DNA molecule, or a population of organisms.
p.3
The Human Genome Project
What is the role of the National Center for Biotechnology Information (NCBI) in genetics research?
NCBI maintains databases containing complete nucleotide sequences of all sequenced genomes and provides tools for searching gene and protein sequences, research articles, and other data.
p.2
The Human Genome Project
What is the genome of an organism?
The collection of DNA molecules that is characteristic of an organism.
p.12
Molecular Genetics and Genetic Engineering
How has molecular genetics advanced the detection of mutant genes?
Molecular genetics has provided new diagnostic tests based on DNA analysis, such as testing for the presence of a mutant allele of the BRCA1 gene, which predisposes carriers to breast cancer.
p.1
Structure and Function of DNA
What distinguishes one nucleotide from another in RNA or DNA?
One nucleotide is distinguished from another by its nitrogen-containing base.
p.8
Gene Expression: Transcription and Translation
What is the role of mRNA in gene expression?
RNA synthesis (transcription) generates a molecule that becomes a messenger RNA (mRNA), which is then translated into a sequence of amino acids in a polypeptide.
p.2
Structure and Function of DNA
How are nucleotides linked in a DNA chain?
By chemical interactions between the phosphate of one nucleotide and the sugar of another nucleotide.
p.5
Structure and Function of DNA
How many genes does Mycoplasma genitalium have compared to a human sperm cell?
Mycoplasma genitalium has 485 genes, whereas a human sperm cell has around 20,500 genes.
p.12
Genetics in Medicine and Genetic Counseling
What are some examples of genetic diseases that are individually rare but significant?
Examples include phenylketonuria, a disorder of amino acid metabolism, which has an incidence of one in 10,000 among newborns.
p.1
Structure and Function of DNA
What are the building blocks of nucleic acids?
Nucleotides are the building blocks of nucleic acids.
p.9
Gregor Mendel's Research on Inheritance
What is the focus of classical genetics?
Classical genetics focuses on how traits are inherited when different strains of organisms are hybridized.
p.2
The Human Genome Project
What is the Human Genome Project?
A worldwide effort to determine the sequence of approximately 3 billion nucleotide pairs in human DNA.
p.12
Genetics in Medicine and Genetic Counseling
What was Sir Archibald Garrod's contribution to genetics?
Sir Archibald Garrod documented how metabolic abnormalities can be traced to mutant alleles in his book 'Inborn Errors of Metabolism,' leading to the identification and cataloging of many inherited human disorders.
p.5
Gene Expression: Transcription and Translation
What is translation?
Translation is the process where the gene's mRNA acts as a template for the synthesis of a polypeptide.
p.12
Molecular Genetics and Genetic Engineering
How is human insulin produced using genetic engineering?
Human insulin is manufactured in bacterial cells that carry the human insulin gene, allowing for industrial-scale production of perfect human insulin.
p.1
Structure and Function of DNA
What major question was answered in the mid-20th century regarding genes?
The major question 'What is a gene?' was answered, showing that genes consist of complex molecules called nucleic acids.
p.3
The Human Genome Project
What is the significance of sequencing the genomes of organisms like the mosquito and the malaria parasite?
It helps understand how genomes are organized and diversified, and has medical, agricultural, or commercial significance.
p.9
Molecular Genetics and Genetic Engineering
What does molecular genetic analysis focus on?
The replication, expression, and mutation of genes at the molecular level.
p.1
Gregor Mendel's Research on Inheritance
What happens to gene copies during gamete formation and fertilization?
During gamete formation, gene copies are reduced from two to one, and during fertilization, two copies are restored.
p.4
DNA Replication and Genetic Information Transmission
What is the primary function of DNA in cellular organisms?
A) To provide structural support
B) To store and transmit genetic information
C) To produce energy
D) To regulate temperature
E) To transport nutrients
B) To store and transmit genetic information
Explanation: DNA's primary function in cellular organisms is to store genetic information and ensure its transmission from cell to cell and from parents to offspring.
p.6
Gene Expression: Transcription and Translation
What happens to the initial methionine after translation is completed in the synthesis of the β-globin polypeptide?
A) It remains in the polypeptide
B) It is replaced by another amino acid
C) It is removed
D) It is duplicated
E) It is phosphorylated
C) It is removed
Explanation: After translation is completed, the initial methionine is removed to produce the mature β-globin polypeptide.
p.2
Structure of DNA by Watson and Crick
What is the significance of the phosphate-sugar backbone in DNA?
A) It determines the sequence of bases
B) It forms the helical structure
C) It links nucleotides together in a chain
D) It pairs with bases
E) It is involved in hydrogen bonding
C) It links nucleotides together in a chain
Explanation: The phosphate-sugar backbone links nucleotides together in a chain, forming the structural framework of DNA to which bases are attached.
p.5
Structure and Function of DNA
Where are genes situated in Mycoplasma genitalium and human sperm cells?
In Mycoplasma genitalium, all genes are on one DNA molecule (single chromosome), while in human sperm cells, genes are on 23 different DNA molecules (23 chromosomes).
p.12
Applications of Genetics in Agriculture
Why have African and European countries been reluctant to grow or purchase BT corn?
Their reluctance is due to factors such as the conflicting interests of small farmers and large agricultural corporations, concerns about the safety of consuming genetically modified food, and the potential impact on nonpest species like butterflies and honeybees.
p.1
Gregor Mendel's Research on Inheritance
What did Mendel emphasize about the nature of genes?
Mendel emphasized that genes are discrete entities and that different alleles can be brought together and separated without compromising their integrity.
p.9
Molecular Genetics and Genetic Engineering
What can be identified through the study of DNA sequences in molecular genetics?
Coding sequences, regulatory sequences, and noncoding sequences of a gene.
p.1
Structure and Function of DNA
What are the three components of a nucleotide?
A nucleotide consists of a sugar molecule, a phosphate molecule, and a nitrogen-containing base.
p.11
Applications of Genetics in Agriculture and Medicine
What is an example of a genetically modified organism (GMO) mentioned in the text?
A) Teosinte
B) BT corn
C) Angus cattle
D) Simmental cattle
E) Wheat
B) BT corn
Explanation: BT corn is an example of a genetically modified organism that carries a gene from the bacterium Bacillus thuringiensis, which provides resistance to certain pests.
p.9
Levels of Genetic Analysis: Classical, Molecular, and Population Genetics
What is chromosome mapping?
A) Identifying the sequence of DNA molecules
B) Localizing genes to specific positions within chromosomes
C) Studying the behavior of proteins
D) Analyzing the outcomes of genetic crosses
E) Examining the effects of environmental conditions on traits
B) Localizing genes to specific positions within chromosomes
Explanation: Chromosome mapping involves localizing genes to specific positions within chromosomes, which helps in understanding the genetic basis of traits.
p.5
Gene Expression: Transcription and Translation
What is transcription?
Transcription is the process where the information in a gene's DNA is copied into a molecule of RNA.
p.1
Gregor Mendel's Research on Inheritance
What type of research did Gregor Mendel conduct?
Mendel studied the inheritance of different traits in peas by interbreeding plants with different traits.
p.11
Applications of Genetics in Agriculture and Medicine
What role do genetic maps play in agriculture?
A) They help identify climate patterns
B) They pinpoint genes of agricultural significance
C) They track animal migration
D) They measure soil quality
E) They predict weather changes
B) They pinpoint genes of agricultural significance
Explanation: Genetic maps are used to locate genes that are important for traits such as grain yield or disease resistance, allowing breeders to design schemes to incorporate specific alleles into agricultural varieties.
p.10
Gene Expression: Transcription and Translation
What is a key capability of geneticists in molecular genetic analysis?
A) Observing natural DNA sequences
B) Cutting DNA molecules at specific sites
C) Measuring the weight of DNA molecules
D) Counting the number of genes in an organism
E) Identifying the color of DNA molecules
B) Cutting DNA molecules at specific sites
Explanation: Geneticists have learned to cut DNA molecules at specific sites, which allows them to manipulate genes by excising and inserting them into different DNA molecules.
p.9
Levels of Genetic Analysis: Classical, Molecular, and Population Genetics
What is the primary focus of classical genetics?
A) Studying DNA sequences
B) Analyzing the outcomes of crosses between different strains of organisms
C) Investigating the molecular structure of genes
D) Examining the behavior of proteins
E) Sequencing genomes
B) Analyzing the outcomes of crosses between different strains of organisms
Explanation: Classical genetics primarily focuses on analyzing the outcomes of crosses between different strains of organisms, much like Mendel's work with peas, to study the inheritance of traits.
p.4
DNA Replication and Genetic Information Transmission
What role do enzymes play in the process of DNA replication?
A) They provide energy for the cell
B) They catalyze the replication process
C) They transport genetic material
D) They store genetic information
E) They regulate cell temperature
B) They catalyze the replication process
Explanation: Enzymes catalyze the process of DNA replication, ensuring that the biochemical steps occur efficiently and accurately.
p.2
Human Genome Project and DNA Sequencing
What is the main goal of the Human Genome Project?
A) To identify the function of all genes
B) To sequence the entire human genome
C) To compare human DNA with other organisms
D) To study the structure of RNA
E) To find a cure for genetic diseases
B) To sequence the entire human genome
Explanation: The main goal of the Human Genome Project is to determine the sequence of approximately 3 billion nucleotide pairs in human DNA, thereby sequencing the entire human genome.
p.1
Discovery of Genes and Alleles
What are the different forms of a gene called?
A) Chromosomes
B) Nucleotides
C) Alleles
D) Proteins
E) Enzymes
C) Alleles
Explanation: Mendel discovered that genes exist in different forms, which we now call alleles. For example, one form of the gene for height allows pea plants to grow tall, while another form limits their growth.
p.1
Structure of DNA by Watson and Crick
What are the building blocks of nucleic acids called?
A) Proteins
B) Enzymes
C) Nucleotides
D) Chromosomes
E) Genes
C) Nucleotides
Explanation: Nucleic acids, such as DNA and RNA, are made of elementary building blocks called nucleotides. Each nucleotide consists of a sugar molecule, a phosphate molecule, and a nitrogen-containing base.
p.7
Gene Expression: Transcription and Translation
What is reverse transcription?
A) The process of DNA being used as a template for RNA synthesis
B) The process of RNA being used as a template for DNA synthesis
C) The process of RNA being translated into polypeptides
D) The process of DNA replication
E) The process of RNA replication
B) The process of RNA being used as a template for DNA synthesis
Explanation: Reverse transcription is the process where RNA is used as a template to synthesize DNA, which is crucial in the life cycle of certain viruses, including HIV.
p.9
Levels of Genetic Analysis: Classical, Molecular, and Population Genetics
What does molecular genetic analysis primarily study?
A) The inheritance of traits
B) DNA sequences
C) The behavior of chromosomes
D) The effects of environmental conditions on traits
E) The anatomy of organisms
B) DNA sequences
Explanation: Molecular genetic analysis primarily studies DNA sequences, which allows geneticists to define genes chemically and understand their internal components and functions.
p.3
Human Genome Project and DNA Sequencing
Who initiated the privately funded project that developed alongside the publicly funded Human Genome Project?
A) James Watson
B) Francis Crick
C) Gregor Mendel
D) Craig Venter
E) Rosalind Franklin
D) Craig Venter
Explanation: Craig Venter, a scientist and entrepreneur, initiated a privately funded project that developed alongside the publicly funded Human Genome Project.
p.8
Evolution and Genetic Variability
What did Charles Darwin and Alfred Wallace propose about genetic variation?
A) It is irrelevant to evolution
B) It allows species to evolve over time
C) It is fixed and unchangeable
D) It only occurs in plants
E) It is caused by environmental factors alone
B) It allows species to evolve over time
Explanation: Darwin and Wallace proposed that genetic variation makes it possible for species to change and evolve over time, introducing an historical perspective into biology.
p.12
Applications of Genetics in Agriculture and Medicine
Why have some African and European countries been reluctant to grow or purchase BT corn?
A) They believe it is less nutritious
B) They are concerned about the safety of consuming genetically modified food
C) They think it is more expensive
D) They prefer traditional farming methods
E) They believe it requires more pesticides
B) They are concerned about the safety of consuming genetically modified food
Explanation: The reluctance is due to concerns about the safety of consuming genetically modified food, as well as the conflicting interests of small farmers and large agricultural corporations.
p.12
Applications of Genetics in Agriculture and Medicine
How is human insulin produced today?
A) Extracted from pigs
B) Synthesized chemically
C) Manufactured in bacterial cells
D) Isolated from cadavers
E) Harvested from plants
C) Manufactured in bacterial cells
Explanation: Human insulin is manufactured in bacterial cells that carry the human insulin gene, allowing for large-scale production of the insulin polypeptide.
p.11
Applications of Genetics in Agriculture and Medicine
What is the primary reason cattle and corn have changed significantly from their wild ancestors?
A) Natural evolution
B) Selective breeding programs
C) Climate change
D) Random mutations
E) Migration patterns
B) Selective breeding programs
Explanation: Cattle and corn have undergone significant changes from their wild ancestors primarily due to selective breeding programs, which have been informed by genetic theory to enhance desirable traits.
p.6
Gene Expression: Transcription and Translation
What is one reason for the large size of the human proteome?
A) Each gene encodes only one polypeptide
B) Polypeptides do not combine to form proteins
C) A particular gene may encode several different, but related, polypeptides
D) Genes are not involved in protein production
E) Proteins are composed of lipids
C) A particular gene may encode several different, but related, polypeptides
Explanation: One reason for the large size of the human proteome is that a particular gene may encode several different, but related, polypeptides, which can combine in complex ways to produce different proteins.
p.10
Evolution and Genetic Variability
What is a foundational aspect of studying biological evolution in population genetics?
A) Measuring DNA molecule weight
B) Determining allele frequencies in a population
C) Observing color changes in organisms
D) Counting the number of genes in an organism
E) Identifying the physical structure of DNA
B) Determining allele frequencies in a population
Explanation: Determining the frequencies of specific alleles in a population and observing if these frequencies change over time is foundational for studying biological evolution.
p.8
Mutations and Their Impact on Genetic Information
Why is the mutant β-globin gene relatively common in some human populations?
A) It provides resistance to cold temperatures
B) It enhances physical strength
C) It reduces susceptibility to malaria
D) It increases lifespan
E) It improves cognitive abilities
C) It reduces susceptibility to malaria
Explanation: People who carry both a mutant and a nonmutant allele of the β-globin gene are less susceptible to infection by the blood parasite that causes malaria, giving them a better chance of survival in environments where malaria is prevalent.
p.3
Human Genome Project and DNA Sequencing
What is the focus of current efforts in the study of the human genome?
A) Sequencing more human genomes
B) Studying how genes influence human characteristics
C) Identifying new genes
D) Cataloging genes by location
E) Sequencing genomes of other species
B) Studying how genes influence human characteristics
Explanation: Current efforts are focused on studying how genes influence the myriad characteristics of humans.
p.3
Human Genome Project and DNA Sequencing
Which of the following organisms' genomes have been sequenced under projects closely allied to the Human Genome Project?
A) Only bacteria
B) Only plants
C) Only animals
D) Only fungi
E) Bacteria, fungi, plants, protists, and animals
E) Bacteria, fungi, plants, protists, and animals
Explanation: The genomes of many organisms, including bacteria, fungi, plants, protists, and animals, have been sequenced under projects closely allied to the Human Genome Project.
p.5
Discovery of Genes and Alleles
What is the smallest known genome among cellular organisms?
A) Human genome
B) Mycoplasma genitalium
C) E. coli
D) Yeast
E) Fruit fly
B) Mycoplasma genitalium
Explanation: Mycoplasma genitalium has the smallest known genome among cellular organisms, consisting of 580,070 nucleotide pairs.
p.11
Applications of Genetics in Agriculture and Medicine
What are GMOs?
A) Organisms with natural mutations
B) Organisms altered by the introduction of foreign genes
C) Organisms that evolved naturally
D) Organisms with no genetic modifications
E) Organisms that are extinct
B) Organisms altered by the introduction of foreign genes
Explanation: GMOs, or genetically modified organisms, are plants and animals that have been altered by introducing genes from other species to enhance certain traits.
p.10
Gene Expression: Transcription and Translation
What is the significance of recombinant DNA molecules?
A) They can be used to measure DNA length
B) They can be replicated in bacterial cells or test tubes
C) They can change the color of an organism
D) They can be used to weigh DNA molecules
E) They can be used to identify DNA sequences
B) They can be replicated in bacterial cells or test tubes
Explanation: Recombinant DNA molecules can be replicated in bacterial cells or in test tubes with appropriate enzymes, allowing for the generation of large quantities of specific genes.
p.7
Mutations and Their Impact on Genetic Information
What can cause mutations in DNA?
A) Only errors during DNA replication
B) Only exposure to chemicals
C) Only exposure to electromagnetic radiation
D) Errors during DNA replication, exposure to chemicals, and electromagnetic radiation
E) Only viral infections
D) Errors during DNA replication, exposure to chemicals, and electromagnetic radiation
Explanation: Mutations can arise from errors during DNA replication, as well as from damage caused by chemicals and electromagnetic radiation, which can alter the DNA sequence.
p.3
Human Genome Project and DNA Sequencing
What is the term for the approach to genetics that involves the analysis of DNA sequences that make up a genome?
A) Genomics
B) Proteomics
C) Transcriptomics
D) Metabolomics
E) Epigenomics
A) Genomics
Explanation: The approach to genetics that involves the analysis of DNA sequences that make up a genome is called genomics.
p.1
Structure of DNA by Watson and Crick
What distinguishes one nucleotide from another in RNA or DNA?
A) The sugar molecule
B) The phosphate molecule
C) The nitrogen-containing base
D) The protein content
E) The enzyme activity
C) The nitrogen-containing base
Explanation: Within RNA or DNA, one nucleotide is distinguished from another by its nitrogen-containing base, which is a key component in the structure of nucleic acids.
p.5
Gene Expression: Transcription and Translation
What is the first amino acid usually added during polypeptide synthesis?
A) Glycine
B) Alanine
C) Methionine
D) Serine
E) Tyrosine
C) Methionine
Explanation: The first amino acid usually added during polypeptide synthesis is methionine.
p.10
Levels of Genetic Analysis: Classical, Molecular, and Population Genetics
What is the primary focus of population genetics?
A) Studying the physical structure of DNA
B) Assessing the variability among individuals in a population
C) Measuring the length of DNA molecules
D) Observing the color changes in organisms
E) Counting the number of genes in an organism
B) Assessing the variability among individuals in a population
Explanation: Population genetics focuses on documenting genetic variability among individuals in a population and understanding its significance, including the frequencies of specific alleles and their changes over time.
p.8
Gene Expression: Transcription and Translation
What is the result of RNA synthesis (transcription) for most genes?
A) A new DNA strand
B) A messenger RNA (mRNA)
C) A polypeptide chain
D) A protein complex
E) A ribosomal RNA (rRNA)
B) A messenger RNA (mRNA)
Explanation: For most genes, RNA synthesis (transcription) generates a molecule that becomes a messenger RNA (mRNA), which carries the genetic information needed for protein synthesis.
p.8
Human Genome Project and DNA Sequencing
What can DNA sequencing reveal about organisms?
A) Their exact age
B) Their physical appearance
C) Their evolutionary relationships
D) Their behavior patterns
E) Their habitat preferences
C) Their evolutionary relationships
Explanation: DNA sequencing allows researchers to see similarities and differences in the genetic material of diverse organisms, helping to establish their evolutionary relationships and construct phylogenetic trees.
p.1
Gregor Mendel's Research on Inheritance
What did Mendel emphasize about the nature of genes?
A) They are continuous entities
B) They are discrete entities
C) They are fluid entities
D) They are temporary entities
E) They are unstable entities
B) They are discrete entities
Explanation: Mendel emphasized that genes are discrete entities, meaning that different alleles of a gene can coexist in the same plant without compromising their integrity.
p.11
Applications of Genetics in Agriculture and Medicine
What is teosinte?
A) A type of cattle
B) A wild ancestor of corn
C) A genetic disorder
D) A bacterial gene
E) A type of wheat
B) A wild ancestor of corn
Explanation: Teosinte is the wild grass from which modern corn is descended. Through selective breeding, corn has been significantly altered from its wild ancestor.
p.4
DNA Replication and Genetic Information Transmission
What ensures the faithful transmission of genetic material during cell division?
A) The presence of ribosomes
B) The complementary nature of DNA strands
C) The action of mitochondria
D) The presence of chloroplasts
E) The process of transcription
B) The complementary nature of DNA strands
Explanation: The faithful transmission of genetic material is ensured by the complementary nature of DNA strands, where A pairs with T and G pairs with C, allowing accurate replication.
p.6
Gene Expression: Transcription and Translation
What specifies the incorporation of an amino acid in the polypeptide chain during translation?
A) Promoter region
B) Enhancer region
C) Triplet codon
D) Silencer region
E) Operator region
C) Triplet codon
Explanation: During translation, each triplet codon in the mRNA specifies the incorporation of an amino acid in the polypeptide chain.
p.2
Structure of DNA by Watson and Crick
Which of the following bases is found in RNA but not in DNA?
A) Adenine (A)
B) Guanine (G)
C) Cytosine (C)
D) Thymine (T)
E) Uracil (U)
E) Uracil (U)
Explanation: RNA contains uracil (U) instead of thymine (T), which is found in DNA. Both RNA and DNA share adenine (A), guanine (G), and cytosine (C).
p.2
Structure of DNA by Watson and Crick
What makes the two chains of a DNA molecule complementary?
A) The sequence of sugars
B) The sequence of phosphates
C) The base-pairing rules
D) The helical structure
E) The presence of uracil
C) The base-pairing rules
Explanation: The two chains of a DNA molecule are complementary because of the base-pairing rules, where adenine (A) pairs with thymine (T) and guanine (G) pairs with cytosine (C).
p.1
Gregor Mendel's Research on Inheritance
How many copies of each gene do pea plants carry according to Mendel?
A) One
B) Two
C) Three
D) Four
E) Five
B) Two
Explanation: Mendel proposed that pea plants carry two copies of each gene. These copies may be the same or different, and during reproduction, one of the copies is randomly incorporated into each gamete.
p.5
Discovery of Genes and Alleles
How many genes does a human sperm cell have?
A) 485
B) 20,500
C) 3.2 billion
D) 580,070
E) 1,000
B) 20,500
Explanation: A human sperm cell has around 20,500 genes.
p.6
Gene Expression: Transcription and Translation
What is the study of all the proteins in cells, including their composition and interactions, called?
A) Genomics
B) Proteomics
C) Transcriptomics
D) Metabolomics
E) Epigenomics
B) Proteomics
Explanation: Proteomics is the study of all the proteins in cells, including their composition, the sequences of amino acids in their constituent polypeptides, the interactions among these polypeptides and among different proteins, and their functions.
p.7
Mutations and Their Impact on Genetic Information
What is the consequence of a mutation in the β-globin gene?
A) It leads to the production of normal red blood cells
B) It causes sickle-cell disease
C) It results in the production of excess hemoglobin
D) It has no effect on the red blood cells
E) It leads to the production of white blood cells
B) It causes sickle-cell disease
Explanation: A mutation in the β-globin gene changes the sixth codon from glutamic acid to valine, resulting in sickle-shaped red blood cells that do not transport oxygen efficiently, causing sickle-cell disease.
p.9
Levels of Genetic Analysis: Classical, Molecular, and Population Genetics
What is the focus of population genetics?
A) The molecular structure of genes
B) The inheritance of traits in individual organisms
C) The genetic makeup of entire populations
D) The behavior of proteins
E) The sequencing of genomes
C) The genetic makeup of entire populations
Explanation: Population genetics focuses on the genetic makeup of entire populations, studying how mutant genes occur, transmit, and spread among groups of organisms.
p.3
Human Genome Project and DNA Sequencing
What was the estimated number of genes in the human genome according to the initial analysis?
A) 10,000 to 20,000
B) 20,000 to 30,000
C) 30,000 to 40,000
D) 40,000 to 50,000
E) 50,000 to 60,000
C) 30,000 to 40,000
Explanation: The initial analysis of the human genome suggested that it contained between 30,000 and 40,000 genes.
p.2
Structure of DNA by Watson and Crick
What is the primary difference between DNA and RNA molecules?
A) DNA is single-stranded while RNA is double-stranded
B) DNA contains uracil while RNA contains thymine
C) DNA is double-stranded while RNA is usually single-stranded
D) DNA is made of proteins while RNA is made of nucleotides
E) DNA is found in the cytoplasm while RNA is found in the nucleus
C) DNA is double-stranded while RNA is usually single-stranded
Explanation: DNA is typically double-stranded, forming a double helix, while RNA is usually single-stranded.
p.1
Gregor Mendel's Research on Inheritance
What happens to the number of gene copies during gamete formation and fertilization?
A) It remains the same
B) It increases
C) It decreases and then is restored
D) It doubles
E) It triples
C) It decreases and then is restored
Explanation: During gamete formation, the number of gene copies is reduced from two to one. During fertilization, the number of gene copies is restored to two, which underlies the rules of inheritance that Mendel discovered.
p.4
DNA Replication and Genetic Information Transmission
Which base pairs are held together by hydrogen bonds in DNA?
A) A with G and T with C
B) A with T and G with C
C) A with C and G with T
D) A with A and G with G
E) T with T and C with C
B) A with T and G with C
Explanation: In DNA, adenine (A) pairs with thymine (T) and guanine (G) pairs with cytosine (C) through hydrogen bonds.
p.2
Structure of DNA by Watson and Crick
What did Watson and Crick discover about the structure of DNA?
A) DNA is a single-stranded molecule
B) DNA is composed of a triple helix
C) DNA consists of two chains of nucleotides held together by hydrogen bonds
D) DNA is made up of proteins
E) DNA is composed of a single chain of nucleotides
C) DNA consists of two chains of nucleotides held together by hydrogen bonds
Explanation: Watson and Crick discovered that DNA consists of two chains of nucleotides held together by hydrogen bonds between specific pairs of bases, forming a double helix.
p.3
Human Genome Project and DNA Sequencing
Which organization maintains the databases that contain the complete nucleotide sequences of all sequenced genomes?
A) World Health Organization (WHO)
B) National Aeronautics and Space Administration (NASA)
C) National Center for Biotechnology Information (NCBI)
D) Centers for Disease Control and Prevention (CDC)
E) Food and Drug Administration (FDA)
C) National Center for Biotechnology Information (NCBI)
Explanation: The National Center for Biotechnology Information (NCBI), maintained by the U.S. National Institutes of Health, maintains the databases that contain the complete nucleotide sequences of all sequenced genomes.
p.12
Mutations and Their Impact on Genetic Information
What is the incidence of phenylketonuria among newborns?
A) 1 in 1,000
B) 1 in 5,000
C) 1 in 10,000
D) 1 in 50,000
E) 1 in 100,000
C) 1 in 10,000
Explanation: Phenylketonuria, a disorder of amino acid metabolism, has an incidence of 1 in 10,000 among newborns.
p.5
Gene Expression: Transcription and Translation
What happens during the translation stage of gene expression?
A) DNA is copied into RNA
B) RNA is modified
C) mRNA acts as a template for polypeptide synthesis
D) Genes are replicated
E) Proteins are degraded
C) mRNA acts as a template for polypeptide synthesis
Explanation: During translation, the gene's mRNA acts as a template for the synthesis of a polypeptide, with each codon specifying the incorporation of a particular amino acid.
p.7
Gene Expression: Transcription and Translation
What is the central dogma of molecular biology?
A) DNA → RNA → Polypeptide
B) RNA → DNA → Polypeptide
C) DNA → Polypeptide → RNA
D) Polypeptide → RNA → DNA
E) RNA → Polypeptide → DNA
A) DNA → RNA → Polypeptide
Explanation: The central dogma of molecular biology describes the flow of genetic information from DNA to RNA to polypeptide (protein), highlighting the process of transcription and translation.
p.9
Levels of Genetic Analysis: Classical, Molecular, and Population Genetics
What significant advancement marked the beginning of molecular genetics?
A) Discovery of the structure of DNA
B) Invention of the microscope
C) Development of chromosome mapping
D) Identification of Mendelian inheritance
E) Study of population genetics
A) Discovery of the structure of DNA
Explanation: The discovery of the structure of DNA marked the beginning of molecular genetics, allowing for the study of gene replication, expression, and mutation at the molecular level.
p.3
Human Genome Project and DNA Sequencing
What is the current estimated number of genes in the human genome?
A) Around 10,500
B) Around 15,500
C) Around 20,500
D) Around 25,500
E) Around 30,500
C) Around 20,500
Explanation: More recent analyses have revised the human gene number downward to around 20,500.
p.1
Discovery of Genes and Alleles
What term did Mendel use to describe the hereditary factors responsible for traits?
A) Chromosomes
B) Nucleotides
C) Genes
D) Proteins
E) Enzymes
C) Genes
Explanation: Mendel postulated the existence of hereditary factors responsible for the traits he studied, which we now call genes.
p.12
Applications of Genetics in Agriculture and Medicine
What is a genetic counselor's role?
A) To perform genetic tests
B) To advise people about the risks of inheriting or transmitting genetic diseases
C) To develop new genetic modification techniques
D) To conduct genetic research
E) To treat genetic diseases
B) To advise people about the risks of inheriting or transmitting genetic diseases
Explanation: Genetic counselors are trained professionals who advise people about the risks of inheriting or transmitting genetic diseases.
p.5
Gene Expression: Transcription and Translation
What is the process called when DNA is copied into RNA?
A) Translation
B) Replication
C) Transcription
D) Mutation
E) Splicing
C) Transcription
Explanation: Transcription is the process by which the information in a gene's DNA is copied into a molecule of RNA.
p.6
Gene Expression: Transcription and Translation
What initiates the translation process in the synthesis of the β-globin polypeptide?
A) Stop codon
B) Promoter region
C) Start codon
D) Enhancer region
E) Silencer region
C) Start codon
Explanation: Translation is initiated by a start codon, which specifies the incorporation of the amino acid methionine (Met) in the synthesis of the β-globin polypeptide.
p.10
Applications of Genetics in Agriculture and Medicine
How is genetics applied in agriculture?
A) By measuring the weight of DNA molecules
B) By observing natural DNA sequences
C) By selective breeding to improve crops and livestock
D) By counting the number of genes in an organism
E) By identifying the color of DNA molecules
C) By selective breeding to improve crops and livestock
Explanation: Genetics is applied in agriculture through selective breeding, which has been used to improve crops and livestock over thousands of generations.
p.8
DNA Replication and Genetic Information Transmission
What role does DNA replication play in genetics?
A) It creates new genes from scratch
B) It serves as a template for RNA synthesis
C) It duplicates the genetic material for cell division
D) It translates RNA into proteins
E) It mutates genes to create variability
C) It duplicates the genetic material for cell division
Explanation: During DNA replication, each strand of a duplex molecule serves as the template for the synthesis of a complementary strand, ensuring that genetic information is accurately copied for cell division.
p.1
Gregor Mendel's Research on Inheritance
What was the primary focus of Gregor Mendel's research?
A) The structure of DNA
B) The inheritance of traits in pea plants
C) The behavior of chromosomes
D) The chemical properties of nucleotides
E) The study of human heredity
B) The inheritance of traits in pea plants
Explanation: Gregor Mendel's research focused on the inheritance of different traits in pea plants, which he grew in the monastery garden. His experiments involved interbreeding plants with different traits to understand how these traits were passed on to offspring.
p.5
Gene Expression: Transcription and Translation
What is the primary function of genes?
A) To store energy
B) To encode proteins
C) To replicate DNA
D) To transport molecules
E) To provide structural support
B) To encode proteins
Explanation: Genes contain the instructions for the synthesis of proteins, which are essential for the development, functioning, and behavior of organisms.
p.5
Gene Expression: Transcription and Translation
What are codons?
A) Single nucleotides
B) Triplets of adjacent nucleotides
C) Amino acids
D) Proteins
E) Enzymes
B) Triplets of adjacent nucleotides
Explanation: Codons are triplets of adjacent nucleotides within a gene that specify the incorporation of an amino acid into a polypeptide.
p.7
Gene Expression: Transcription and Translation
What is the role of RNA molecules that do not encode polypeptides?
A) They are involved in DNA replication
B) They play important roles within cells
C) They are used for energy storage
D) They are waste products of transcription
E) They are involved in protein degradation
B) They play important roles within cells
Explanation: Many genes produce RNA molecules that do not encode polypeptides but have crucial functions within cells, such as regulatory roles and involvement in various cellular processes.
p.8
Mutations and Their Impact on Genetic Information
How do mutations contribute to biological evolution?
A) By creating new species instantly
B) By altering the DNA sequence of a gene
C) By eliminating genetic variability
D) By stabilizing the genetic code
E) By preventing natural selection
B) By altering the DNA sequence of a gene
Explanation: Mutations can alter the DNA sequence of a gene, creating genetic variability that serves as the basis for biological evolution over many generations.
p.3
Human Genome Project and DNA Sequencing
What is one of the significant impacts of DNA sequencing projects on genetics?
A) Increased cost of genetic research
B) Limited access to genetic information
C) Ability to study genes at the molecular level with ease
D) Decreased interest in genetic research
E) Reduced number of genetic databases
C) Ability to study genes at the molecular level with ease
Explanation: DNA sequencing projects have transformed genetics by allowing genes to be studied at the molecular level with relative ease.
p.12
Gene Expression: Transcription and Translation
What is the purpose of diagnostic tests based on DNA analysis?
A) To identify nutritional deficiencies
B) To detect mutant genes in individuals
C) To measure blood sugar levels
D) To determine blood type
E) To assess overall health
B) To detect mutant genes in individuals
Explanation: Diagnostic tests based on DNA analysis are used to detect mutant genes in individuals, such as the BRCA1 gene that predisposes carriers to breast cancer.
p.4
DNA Replication and Genetic Information Transmission
What is the result of DNA replication?
A) One identical DNA duplex
B) Two identical DNA duplexes
C) Three identical DNA duplexes
D) Four identical DNA duplexes
E) No identical DNA duplexes
B) Two identical DNA duplexes
Explanation: DNA replication results in the formation of two identical DNA duplexes from one original duplex, ensuring genetic continuity.
p.8
Evolution and Genetic Variability
What is a phylogenetic tree?
A) A diagram showing the physical traits of organisms
B) A chart of genetic mutations
C) A representation of evolutionary relationships among organisms
D) A list of species in alphabetical order
E) A map of geographical distribution of species
C) A representation of evolutionary relationships among organisms
Explanation: A phylogenetic tree, or phylogeny, is a diagram that shows the evolutionary relationships among organisms based on similarities and differences in their genetic material.
p.12
Discovery of Genes and Alleles
What was Sir Archibald Garrod's contribution to genetics?
A) He discovered the structure of DNA
B) He identified the first genetic disease
C) He published a book on inborn errors of metabolism
D) He developed the first genetic test
E) He created the first genetically modified organism
C) He published a book on inborn errors of metabolism
Explanation: Sir Archibald Garrod published a book entitled 'Inborn Errors of Metabolism,' documenting how metabolic abnormalities can be traced to mutant alleles.
p.5
Discovery of Genes and Alleles
How many nucleotide pairs are in the human genome?
A) 580,070
B) 1 billion
C) 3.2 billion
D) 20,500
E) 485
C) 3.2 billion
Explanation: The human genome consists of approximately 3.2 billion nucleotide pairs.
p.12
Applications of Genetics in Agriculture and Medicine
What is the primary benefit of BT corn plants?
A) They grow faster than regular corn plants
B) They are resistant to attacks by the European corn borer
C) They produce more corn per plant
D) They require less water to grow
E) They are more nutritious than regular corn plants
B) They are resistant to attacks by the European corn borer
Explanation: BT corn plants carry a gene from Bacillus thuringiensis that encodes a protein toxic to many insects, making them resistant to attacks by the European corn borer.
p.1
Structure of DNA by Watson and Crick
What was the significant discovery made by Watson and Crick?
A) The inheritance of traits in pea plants
B) The behavior of chromosomes
C) The structure of DNA
D) The chemical properties of proteins
E) The study of human heredity
C) The structure of DNA
Explanation: Watson and Crick are credited with discovering the structure of DNA, which was a significant milestone in understanding the molecular basis of genes.
p.5
Gene Expression: Transcription and Translation
What is the role of mRNA in gene expression?
A) To replicate DNA
B) To act as a template for protein synthesis
C) To store genetic information
D) To transport amino acids
E) To modify nucleotides
B) To act as a template for protein synthesis
Explanation: mRNA contains all the information needed for the synthesis of a polypeptide and acts as a template during the translation stage of gene expression.
p.5
Gene Expression: Transcription and Translation
What is the collection of all different proteins in an organism called?
A) Genome
B) Transcriptome
C) Proteome
D) Chromosome
E) Codon
C) Proteome
Explanation: The proteome refers to the collection of all the different proteins in an organism.
