Deck 10: The Nature of the Gene and the Genome

Question 1

What is the major abnormality seen in the daughter cells of an egg that has been fertilized by more than one sperm?

A)The daughter cells have more cilia.
B)The daughter cells are smaller.
C)The daughter cells have variable numbers of chromosomes.
D)The daughter cells enter meiosis unexpectedly.
E)The daughter cells swell to three times their normal size.

Answer 1

C

Question 2

What would happen if meiosis did not include a reduction division?

A)The number of chromosomes in a species would remain the same with each generation.
B)The number of chromosomes in a species would double with each generation.
C)The number of chromosomes in a species would halve with each generation.
D)The number of chromosomes in a species would quadruple with each generation.
E)Chromosomes would shrink prior to each cell division.

Answer 2

B

Question 3

The building blocks of a nucleotide are ___________.

A)a pentose sugar and a phosphate group
B)a pentose sugar and a nitrogenous base
C)a phosphate group and a nitrogenous base
D)a pentose sugar,a phosphate group and a nitrogenous base
E)a pentose sugar,a phosphate group and an amino acid

Answer 3

D

Question 4

Who was the first scientist to propose that meiosis included a reduction division?

A)Edouard van Beneden
B)Theodore Boveri
C)Gregor Mendel
D)August Weismann
E)Walther Flemming

Question 5

The backbone of a DNA molecule is _________.

A)made up of sugars alone
B)made up of nitrogenous bases alone
C)made up of phosphate groups alone
D)made up of alternating phosphate and sugar groups
E)made up of alternating sugars and nitrogenous bases

Question 6

Which of the following is not a conclusion reached by Mendel?

A)Characteristics of plants are governed by distinct factors or units of inheritance.
B)Gametes from each plant have two copies of the gene for each trait.
C)An organism's two alleles segregate from each other during gamete formation.
D)The two genes for a trait carried by an organism may be identical to one another.
E)The two genes for a trait carried by an organism may be different from one another.

Question 7

The nitrogenous base attaches to the ____-carbon of the nucleotide's sugar.

A)1'
B)2'
C)3'
D)5'
E)1

Question 8

What is the name of chromosomes that have as many as 1024 times the number of DNA strands usually present?

A)polymorphic chromosomes
B)polytene chromosomes
C)homologous chromosomes
D)heterozygous chromosomes
E)papillosomes

Question 9

How many chromosomes would a sexually-reproducing organism with 6 chromosomes in generation 0 have in generation 4 if there are reduction divisions in meiosis?

A)6
B)12
C)24
D)48
E)96

Question 10

The individual banding patterns on Drosophila chromosomes provided evidence for the validity of what phenomenon?

A)mitosis
B)meiosis
C)the ability to map the positions of genes on their chromosomes
D)translation
E)respiration

Question 11

What was the original strain of fruit flies called?

A)wild ones
B)originals
C)wild type
D)normal type
E)dominant type

Question 12

The behavior of what cell constituent correlated perfectly with that of Mendel's genetic factors?

A)the mitochondria
B)the endoplasmic reticulum
C)the homologous pairs of chromosomes
D)the homologous pairs of centrioles
E)the nucleolus

Question 13

The Law of Independent Assortment states that ____________.

A)segregation of an allelic pair for one trait has no effect on segregation of alleles for another trait
B)an organism's two alleles for a gene separate from one another during gamete formation
C)segregation of an allelic pair for one trait has a great effect on segregation of alleles for another trait
D)an organism's three alleles for a gene separate from one another during gamete formation
E)gametes are diploid and highly variable

Question 14

What word below refers to a pair of homologous chromosomes?

A)chromophores
B)bivalent
C)birefringence
D)bilateral
E)nucleolus

Question 15

Which of the following statements was initially a disadvantage of using the fruit fly for genetic studies?

A)They have a short generation time from egg to maturity.
B)They produce up to 1000 eggs in a lifetime.
C)They are easy to house and breed.
D)There was only one strain of flies available.
E)They are inexpensive to maintain.

Question 16

Which of the following is an RNA nucleoside?

A)a phosphate group,adenine and ribose
B)a phosphate group,guanine and deoxyribose
C)cytosine and ribose
D)thymine and deoxyribose
E)a phosphate group and adenine

Question 17

Purines are characterized by _______; pyrimidines are characterized by ______.

A)two rings; one ring
B)one ring; two rings
C)two rings; three rings
D)two rings; two rings
E)two rings; one chain

Question 18

Which of the following is a DNA nucleotide?

A)a phosphate group,adenine and ribose
B)a phosphate group,guanine and deoxyribose
C)cytosine and ribose
D)thymine and deoxyribose
E)a phosphate group and adenine

Question 19

What appears to be the reason for the production of the large Drosophila larvae salivary gland cells?

A)to allow less gene expression
B)to allow moderate gene expression
C)to allow cells to maintain their high secretory activity
D)to allow the cells to take up more space
E)to allow the cells to digest larger amounts of phagocytic material

Question 20

The effect of _________ on embryonic development is ___________.

A)polyandry,disruptive cell divisions and the early death of the embryo
B)mitosis,disruptive cell divisions and the early death of the embryo
C)polyspermy,disruptive cell divisions and the early death of the embryo
D)polyspermy,the embryo develops normally but is twice as large
E)polyandry,the embryo develops normally but is twice as large

Question 21

The bonds that hold DNA and RNA together are known as __________.

A)3'-4'-phosphodiester linkages
B)3'-5'-phosphodiester linkages
C)phosphate esters
D)1,4-glycosidic linkages
E)peptide bond

Question 22

The genome is essentially equivalent to all of the genetic information that is present in a ______ set of chromosomes.

A)triploid
B)double
C)haploid
D)diploid
E)polyploid

Question 23

What technique supplied the data that led Watson and Crick to the double helical structure of DNA?

A)sucrose density centrifugation
B)polyacrylamide gel electrophoresis
C)X-ray diffraction/crystallography
D)autoradiography
E)ion exchange chromatography

Question 24

The information encoded in DNA resides in ________.

A)phosphates in the backbone
B)sugars in the backbone
C)the DNA base sequence
D)the sugars and phosphate groups together
E)the phosphodiester linkages

Question 25

The ends of a polynucleotide chain are the ____ end and the ____ end.

A)5',N-terminal
B)3',4'
C)3',5'
D)N-terminal,C-terminal
E)3',C-terminal

Question 26

Which type of DNA sequence is typified by short sequences of DNA (five to a few hundred base pairs in length)repeated a large number of times in tandem to form very large clusters,each containing up to several million base pairs of DNA?

A)satellite DNAs
B)minisatellite DNAs
C)microsatellite DNAs
D)consensus sequences
E)microminisatellite DNAs

Question 27

The original model of DNA structure stated that each unit of structure in DNA contained all four nitrogenous bases; it was called the ________.

A)Endosymbiotic Theory
B)Induced Fit Model
C)Lock and Key Model
D)Tetranucleotide Theory
E)Evolutionary Theory

Question 28

Which type of enzyme makes a transient break in both DNA duplex strands and then transports another segment of a DNA molecule (or separate molecule entirely)through the break and reseals the severed strands?

A)Type I topoisomerase
B)Type II topoisomerase
C)Type I topologicase
D)Type II topologicase
E)Type I isomerase

Question 29

What statement below explains the uniform width of the DNA molecule along its entire width?

A)A purine nitrogenous base always pairs with another purine nitrogenous base.
B)A pyrimidine nitrogenous base always pairs with another pyrimidine nitrogenous base.
C)A pyrimidine nitrogenous base always pairs with a purine nitrogenous base.
D)Repulsion between phosphate groups keeps the strands a uniform distance apart.
E)Attraction between phosphate groups keeps the strands a uniform distance apart.

Question 30

Which of the following is guanosine?

A)ribose + guanine
B)guanine + deoxyribose
C)guanine + thymine
D)deoxyribose + guanine + phosphate group
E)ribose + guanine + phosphate group

Question 31

How is the extent of DNA denaturation usually measured?

A)Absorbance of UV light by DNA increases as DNA denatures.
B)Absorbance of UV light by DNA decreases as DNA denatures.
C)Absorbance of infrared light by DNA increases as DNA denatures.
D)The temperature of the solution indicates the degree of denaturation.
E)The color of the solution indicates the degree of denaturation.

Question 32

You isolate DNA from a particular organism and analyze it.The amount of adenine was 6 µmoles and the A+T/G+C ratio is 4.0.How much guanine should be in the sample?

A)6 µmoles
B)3 µmoles
C)1)5 µmoles
D)4 µmoles
E)12 µmoles

Question 33

The variety and number of DNA sequence copies in the genome are known as genome _______.

A)complexion
B)complicatedness
C)complexity
D)variability
E)reannealation

Question 34

What gives a DNA molecule its negative charge?

A)deoxyribose
B)ribose
C)phosphate groups
D)chlorine ion
E)adenine

Question 35

________ refers to the fact that the sequence of one DNA strand specifies the sequence of the other strand in the double helix.

A)Indirectionality
B)Complexity
C)Complementarity
D)Similarity
E)Compulsivity

Question 36

Which type of enzyme is essential for processes like DNA replication and transcription to prevent excessive supercoiling from developing as the complementary strands of the DNA duplex separate and unwind?

A)topoisomerase
B)telomerase
C)topologicase
D)helicase
E)isomerase

Question 37

Different versions of a gene are called _________.

A)heterologues
B)homologues
C)allogues
D)alleles
E)mutoids

Question 38

What function does topoisomerase II serve during mitosis?

A)It pulls the chromosomes apart in association with the spindle.
B)It organizes the spindle.
C)It is needed to disentangle DNA molecules before duplicated chromosomes can be separated during mitosis.
D)It moves genes from place to place.
E)It lengthens chromosomes at the end of mitosis.

Question 39

Why are satellite DNAs separated from the bulk of the genome during density gradient centrifugation?

A)Their base composition is similar to that of the bulk of the genome.
B)Their base composition is significantly different from that of the bulk of the genome.
C)Satellite DNAs have higher molecular weights.
D)Satellites have a higher negative charge than the bulk of the genome.
E)Satellites have a higher positive charge than the bulk of the genome.

Question 40

In a right-handed double helix,if one looks down the central axis of the molecule,_________.

A)each strand follows a counterclockwise path as it moves away from the observer
B)each strand follows a clockwise path as it moves away from the observer
C)each strand follows a rectangular path as it moves toward the observer
D)each strand follows a clockwise path as it moves toward the observer
E)one strand follows a clockwise path as it moves away from the observer,the other follows a clockwise path as it moves toward the observe

Question 41

Hemoglobin molecules analyzed at various times during an animal's life seem to be highly variable.What is the explanation?

A)Contaminants at various points in an organism's life cause the variation in data.
B)Hemoglobin denatures when isolated from older embryos.
C)The combinations of of $\alpha$ -family and $\beta$ -family globin polypeptides differ with developmental stage.
D)Hemoglobins are chemically altered as they age.
E)Hemoglobins bind copper ions instead of iron ions.

Question 42

When a gene is duplicated one or more times,it gives rise to a group of genes that may diverge by mutation,but their sequences will generally remain closely related and they will encode similar polypeptides.The proteins and genes produced in this way can be referred to as ________.

A)isotopes
B)isomers
C)isosceles
D)gene families
E)gene isoforms

Question 43

In which of the following organisms is polyploidization particularly common?

A)flowering plants
B)wheat
C)bananas
D)coffee
E)All of these are correct.

Question 44

Satellite DNAs have been localized to what location during in situ hybridization studies?

A)nucleolus
B)centromere
C)spindle
D)mitochondria
E)nucleosomes

Question 45

Why would much larger satellite DNAs be unlikely to form satellites in density gradients?

A)Larger satellites are less likely to have a base composition similar to that of the bulk of the genome.
B)Larger satellites have higher molecular weights than the bulk of the genome.
C)Larger satellites will have the same molecular weight as the bulk of the genome.
D)Larger satellites are more likely to have a base composition similar to that of the bulk of the genome.
E)Larger satellites have the same charge as the bulk of the genome.

Question 46

Which phrase below describes the structure of hemoglobin?

A)either an $\alpha$ -globin or a $\beta$ -globin chain
B)an $\alpha$ -globin and a $\beta$ -globin chain
C)two $\alpha$ -globin and two $\beta$ -globin chains
D)three $\alpha$ -globin chains and one $\beta$ -globin chain
E)four $\alpha$ -globin or four $\beta$ -globin chains

Question 47

Segmental duplication is ____________.

A)the duplication of one base at a time
B)the duplication of a large block of genetic material (from a few to hundreds of kilobases in length)
C)the duplication of one chromosome at a time
D)the duplication of the centromeres alone
E)the duplication of the mitochondrial DNA alone

Question 48

What causes unequal crossing over?

A)A pair of homologous chromosomes align perfectly during meiosis followed by genetic exchange.
B)A pair of homologous chromosomes aligns imperfectly during meiosis followed by genetic exchange.
C)Sections of the chromosome are replicated spontaneously.
D)Pieces of chromosomes are translocated from one place to another.
E)Chromatids on different chromosomes align imperfectly followed by genetic exchange.

Question 49

The labeled,single-stranded DNAs used to localize the positions of specific complementary DNA sequences within the chromosomes in in situ hybridization studies are called _______.

A)altoids
B)probatives
C)probes
D)bindins
E)prorbs

Question 50

What is one explanation for the wide discrepancies in genome sizes from species to species?

A)More advanced organisms have more DNA.
B)Genomes have an extremely variable number of repeated DNA sequences that do not code for proteins.
C)Some organisms have multiple repeats of each gene.
D)More advanced organisms have more genes.
E)More advanced organisms have more centromeric DNA.

Question 51

Why are satellite DNAs called satellite DNAs?

A)They orbit the Earth.
B)They form bands in a density gradient within the main band formed by the bulk of the genome.
C)They form bands in a density gradient separate from the main band formed by the bulk of the genome.
D)They form bands on an agarose gel separate from the main band formed by the bulk of the genome.
E)They form small bands on an agarose gel within the main band formed by the bulk of the genome.

Question 52

What percentage of the human genome codes for the amino acids in our proteins?

A)15%
B)23%
C)about 1.5%
D)about 7.5%
E)70%

Question 53

To what does avidin directly bind with high affinity?

A)RNA
B)DNA
C)fish
D)biotin
E)centromeres

Question 54

When a gene has been duplicated one or more times,what are the possible things that can happen to the duplicated gene?

A)The duplicated gene can accumulate favorable mutations and acquire a new function.
B)The duplicated gene can be lost during evolution through deletion.
C)The duplicated gene can be rendered nonfunctional by unfavorable mutations.
D)If there are two copies of the gene,both could undergo mutation so that each evolves a more specialized function than the original gene.
E)All of these are correct.

Question 55

Susumu Ohno proposed that the evolution of vertebrates from a much simpler invertebrate ancestor was made possible by two separate rounds of whole-genome duplication during an early evolutionary period.How was it proposed that the whole-gene duplication led to the encoding of the more complex vertebrate body?

A)The extra genes immediately resulted in a bigger body.
B)The many extra genes generated by genetic duplication can be molded over time into new genes needed to encode the complex vertebrate body.
C)The genes could rapidly combine to make new structures.
D)The gene duplication makes the nucleus bigger and makes the cell more versatile.
E)The duplication of the chromosomes leads to new cytoplasmic structures in the first generation.

Question 56

Which polyploidization mechanism is thought to occur most often in plants?

A)Two related species mate,forming an organism with the combined chromosomes from both parents.
B)A single-celled embryo duplicates its chromosomes,but they are not separated into separate cells and remain in a single cell that develops into a viable embryo.
C)Chromosomes spontaneously split down the middle during the G1 portion of the cell cycle.
D)Plants form a syncytium.
E)There is a spontaneous duplication of chromosomes at random.

Question 57

Why is it thought that certain primitive fish diverged from vertebrates before the globin gene was first duplicated?

A)The fish are very old.
B)The fish do not have any hemoglobin.
C)The hemoglobin of the fish consists of 8 polypeptide subunits.
D)These fish have only one globin gene instead of multiple globin genes,suggesting that they diverged from other vertebrates before the first duplication of the globin gene.
E)These fish have four globin genes instead of a single globin gene,suggesting they diverged from other vertebrates before the first duplication of the globin gene.

Question 58

How is a cluster of tandemly repeated segments generated at a localized site within a chromosome?

A)by a single duplication event
B)by multiple vaporizations
C)by repeated duplication of a particular sequence over a number of generations
D)by a single inversion event
E)by a single deletion even

Question 59

What evidence supports the Ohno suggestion about vertebrate evolution from ancestral invertebrates by whole-genome duplication?

A)Modern vertebrates have four times the number of certain groups of genes compared to their homologues in Amphioxus.
B)Modern vertebrates and Amphioxus have exactly the same number of certain groups of genes.
C)Modern vertebrates have six times the number of certain groups of genes compared to their homologues in Amphioxus.
D)Amphioxus has four times the number of certain groups of genes compared to their homologues in modern vertebrates.
E)Amphioxus has eight times the number of certain groups of genes compared to their homologues in modern vertebrates.

Question 60

What kind of DNA sequence makes up from about 20% to more than 80% of the total DNA in a eukaryotic genome,depending on the organism,and includes sequences repeated within the genome a few times to tens of thousands of times?

A)moderately repeated DNA sequences
B)nonrepeated sequences
C)highly repeated sequences
D)satellites,minisatellites and microsatellites
E)very unique sequence DNA

Question 61

_______ is thought to be derived from a reverse transcriptase encoded by an ancient retrotransposon.

A)Phosphatase
B)Esterase
C)Telomerase
D)Protein kinase
E)Phosphodiesterase

Question 62

________ plays a key role in replicating DNA at the ends of chromosomes.

A)PolyA polymerase
B)DNA polymerase
C)Telomerase
D)Protein kinase
E)Phosphodiesterase

Question 63

Conserved portions of mammalian genomes are assumed to be _________.

A)repeated
B)important
C)unimportant
D)long
E)extraordinary

Question 64

The genetic rearrangement that Barbara McClintock discovered was called _________ and the mobile genetic elements she discovered were called ________.

A)transposition,transposable elements
B)transposable elements,transposition
C)transference,transferable elements
D)mutations,mutable elements
E)transposition,transposables

Question 65

A new area of biological study called ________ has emerged that focuses on the ways that proteins work together as complex networks rather than as individual actors.

A)systems biology
B)complex biology
C)systematics
D)complexity
E)networkonics

Question 66

How do Alu sequences contribute to the genetic diversity in the human population?

A)Their transposition generates considerable differences in the timing of Alu sequence movement.
B)Alu sequences amplify the effects of genes that they abut.
C)Their transposition generates considerable differences in the location of Alu sequences.
D)Alu sequences change the DNA sequences of the genes that they abut.
E)Alu sequences reshuffle genes on every chromosome.

Question 67

A single gene can encode a number of related proteins as a result of a process called _______.

A)alternative splicing
B)gene expression
C)polymorphism
D)alternative addition
E)alternative expression

Question 68

A transposable element is a type of genetic parasite that can invade a host genome from the outside world,spread within the genome and be transmitted to offspring.Under what circumstances,would a transposable element not be able to accomplish this?

A)if it has serious adverse effects on the ability of the host to survive and reproduce
B)if it does not have serious adverse effects on the ability of the host to survive and reproduce
C)if it speeds up the activity of amylase
D)if is slows down the activity of triosephosphate isomerase
E)if it increases the rate at which an organism can sense time

Question 69

What does it mean if portions of the noncoding regions of the genome are conserved?

A)Exons code for proteins.
B)Exons are not as important as once was thought.
C)Introns and other supposedly useless,noncoding parts of the genome actually have important,unidentified functions.
D)Introns have no importance.
E)Introns must be excised to maintain consistency.

Question 70

What may be the primary mechanism in the evolution of proteins that are composed of domains derived from different ancestral genes?

A)gene duplication
B)transposable elements
C)crossing over
D)random assortment
E)genetic hyperbole

Question 71

What word below most accurately describes transposable elements?

A)stable
B)offspring
C)helpers
D)genetic parasite
E)genetic symbionts

Question 72

Current estimates place the number of protein-coding human genes in the neighborhood of _______.

A)100,000
B)30,000
C)20,000
D)75,000
E)5,000

Question 73

What do many people believe that the function of transposable elements is?

A)It is thought that they are mostly junk with no function.
B)It is thought that they transpose base pairs.
C)It is thought that they make enzymes more efficient.
D)It is thought that they make enzymes less efficient.
E)It is thought that they denature enzymes.

Question 74

A significant proportion of functional DNA sequences are __________ and thus are _______.

A)stable over time,highly conserved
B)constantly evolving,not highly conserved
C)constantly evolving,highly conserved
D)invariant,not highly conserved
E)duplicated,invariant

Question 75

The globin gene cluster contains stretches of DNA that are homologous to the sequences of functional globin genes,but contain severe accumulated mutations that render them nonfunctional.Most of these noncoding regions have no known function.They are considered to be evolutionary relics and are called _________.

A)reliquaries
B)pseudoemissaries
C)pseudogenes
D)pseudoproteins
E)pseudoglobins

Question 76

Humans have roughly the same number of protein-coding genes as _________.

A)a mouse
B)a mustard plant
C)a puffer fish
D)a chicken
E)All of these are correct.

Question 77

DNA sequences in bacteria that on rare occasions moved from one place in the genome to another are called ________.

A)movers
B)jumpons
C)transposons
D)transpodons
E)jumposons

Question 78

How might a transposase be responsible for our ability to ward off infectious disease?

A)Enzymes that make the proteins in antibodies also make transposases.
B)Enzymes involved in antibody gene rearrangement may be derived from a transposase encoded by an ancient DNA transposon.
C)Antibodies are transposases.
D)Most transposases are antibodies.
E)Enzymes involved in transposase gene rearrangement may be derived from ancient antibodies.

Question 79

Transposase is an enzyme that __________.

A)degrades transposons
B)builds transposons
C)catalyzes transposon excision from a donor DNA site and its subsequent insertion at a target DNA site
D)degrades target DNA
E)rearranges transposon DNA

Question 80

Which type of DNA sequence in the genome is interspersed and probably arose by transposition of mobile genetic elements?

A)satellite DNA
B)microsatellite DNA
C)minisatellite DNA
D)moderately repeated DNA sequences
E)unique sequence DNA