All Bonus Quizzes 1-16

Question 1

If an organism contains 30% cytosine (C), the following is true:
A. It will contain 30% thymine
B. It will contain 20% adenine
C. It will contain 40% guanine
D. It will contain 60% guanine
E. It will contain 70% thymine

Answer 1

B. It will contain 20% adenine

Question 2

Griffith’s experiment injecting a mixture of dead and live bacteria into mice demonstrated that
A. DNA is double-stranded
B. The genetic material of bacteria differs from the genetic material of mice
C. bacteria can recover from heat treatment if live helper cells are present
D. a factor was capable of transforming one bacterial cell type to another
E. Bacteria contained deoxyribonucleic acid

Answer 2

D. a factor was capable of transforming one bacterial cell type to another

Question 3

Which of the following statements is false
A. Genes are nucleotide sequences that encode functional RNAs
B. Genes are carried on chromosomes
C. Genes are expressed at the same level in all cell types and tissues of an organism
D. Gene products (RNAs and proteins) influence phenotypic traits by regulating biochemical
processes
E. The nucleotide sequence of genes determines their function

Answer 3

C. Genes are expressed at the same level in all cell types and tissues of an organism

Question 4

In the experiment of Avery, McLeod, and McCarty, the addition of RNAse and protease to the DNA
extracts
A. prevented the conversion of type S bacteria into type R bacteria
B. allowed the conversion of type S bacteria into type R bacteria
C. prevented the conversion of type R bacteria into type S bacteria
D. allowed the conversion of type R bacteria into type S bacteria
E. killed all the bacteria

Answer 4

D. allowed the conversion of type R bacteria into type S bacteria

Question 5

Okasaki fragments are a consequence of
A. the inability of the DNA polymerase to initiate a new DNA strand
B. the inability of the DNA polymerase to correct replication errors
C. random strand breakages resulting from supercoiling
D. mutations in the gene for DNA ligase
E. the inability of the DNA polymerase to polymerize in the 3’ to 5’ direction

Answer 5

E. the inability of the DNA polymerase to polymerize in the 3’ to 5’ direction

Question 6

Which terms accurately reflect the nature of DNA replication in prokaryotes?
A. single ori, bidirectional, conservative
B. single ori, unidirectional, conservative
C. multiple ori, bidirectional, semiconservative
D. single ori, bidirectional, semiconservative
E. multiple ori, unidirectional, semiconservative

Answer 6

D. single ori, bidirectional, semiconservative

Question 7

DNA polymerase III adds nucleotides
A. to the 3’ end of the RNA primer
B. to the 5’ end of the RNA primer
C. in the place of the primer RNA after it is removed
D. to both ends of the RNA primer
E. to internal sites in the DNA template

Answer 7

A. to the 3’ end of the RNA primer

Question 8

The two DNA strands in a DNA double helix are said to be complementary to one another. What does
this mean?
A. One strand unequivocally determines the nucleotide (base) sequence of the other strand.
B. The two strands are interchangeable (have the same nucleotide or base sequence).
C. The two strands are interchangeable, but one strand is reversed with respect to the other.
D. The two strands are antiparallel (5’-end of one strand is where the 3’-end of the other strand is).
E. Separation of the two strands has no “cost” (does require no or only very little energy).

Answer 8

A. One strand unequivocally determines the nucleotide (base) sequence of the other strand.

Question 9

DNA polymerases and RNA polymerases have the following in common:
A. They use a 3’ to 5’ DNA strand as template
B. They synthesize in the 5’ to 3’ direction
C. They need a short primer to initiate synthesis
D. A and B are correct
E. All are correct

Answer 9

D. A and B are correct

Question 10

The poly(A) tail of mRNAs
A. Is added to the 3¢ end of mRNAs.
B. Is found on most mature eukaryotic mRNAs.
C. is added in the nucleus.
D. Helps prevent degradation of eukaryotic mRNAs.
E. All of the above.

Answer 10

E. All of the above.

Question 11

The sigma subunit of bacterial RNA polymerase
A. Binds to a bacterial gene’s promoter
B. Is composed of both polypeptide and RNA molecules
C. Is required for RNA polymerization
D. Is required for termination of transcription
E. Is required for ribosomal binding

Answer 11

A. Binds to a bacterial gene’s promoter

Question 12

Nucleosomes are composed of which class of molecules?
A. histones
B. glycoproteins
C. lipids
D. H1 histones
E. nonhistone chromosomal proteins

Answer 12

A. histones

Question 13

Which of the following is (are) required for splicing to occur?
A. two transesterification reactions
B. intact, naturally occurring introns
C. formation of a lariat like structure
D. a branch-point A residue
E. all of the above

Answer 13

E. all of the above

Question 14

The genetic code is _________, meaning that an amino acid may be coded by more than one codon
A. Unambiguous
B. Degenerate
C. Comma-less
D. Universal
E. Overlapping

Answer 14

B. Degenerate

Question 15

A primary mRNA has to undergo the following modifications in the eukaryotic cell nucleus
A. 3’ polyadenylation
B. 5’ capping
C. Intron splicing
D. A and B are correct
E. A, B, and C are correct

Answer 15

E. A, B, and C are correct

Question 16

How would the artificial mRNA GUGUGUGUGU etc. be read by the translational machinery based on
our knowledge of the genetic code?
A. Two base, not overlapping
B. Two base, overlapping
C. Three base, not overlapping
D. Three base, overlapping
E. Four base, not overlapping

Answer 16

C. Three base, not overlapping

Question 17

The secondary structure of a protein includes the following elements:
A) gamma and delta
B) alpha and gamma
C) alpha-helix and beta-pleated sheet
D) hydrophobic clusters
E) disulfide bridges

Answer 17

C) alpha-helix and beta-pleated sheet

Question 18

A class of mutations that results in multiple contiguous amino acid changes in proteins is likely to
be the following:
A) base analog.
B) transversion.
C) transition.
D) frameshift.
E) recombinant.

Answer 18

D) frameshift.

Question 19

Mutations that reduce the function encoded by the wild-type allele are known as ________, while
mutations that eliminate all function are known as ________:
A) null mutations; neomorphic mutations
B) hypomorphic mutations; null mutations
C) hypermorphic mutations; hypomorphic mutations
D) conditional mutations; null mutations
E) neomorphic mutations; null mutations

Answer 19

B) hypomorphic mutations; null mutations

Question 20

A point mutation within the coding sequence that causes no amino acid change in the resulting
polypeptide is a …
A) a. silent mutation
B) b. missense mutation
C) c. nonsense mutation
D) d. frameshift mutation
E) e. insertion

Answer 20

A) a. silent mutation

Question 21

A CG base pair was changed by deamination of cytosine to a ____base pair, causing a
_______mutation
A) TA base pair; transversion
B) GC base pair; transition
C) UG base pair; transversion
D) TA base pair; transition
E) GC base pair; transition

Answer 21

D) TA base pair; transition

Question 22

Conditional mutations are more likely to result from which of the following alterations to the
coding region of a gene:
A) a mutation caused by a base addition (insertion)
B) a mutation caused by a deletion
C) a mutation caused by X-rays
D) a mutation caused by a tautomeric shift
E) either A) or B) are correct

Answer 22

D) a mutation caused by a tautomeric shift

Question 23

_________ radiation induces mutations because it causes abnormal bonds to form in
DNA.
A) X-ray
B) gamma
C) ultraviolet
D) infrared
E) microwave

Answer 23

C) ultraviolet

Question 24

5-Bromuracil induces mutations because it
A) replaces a T and binds to G rather than A
B) replaces a G and binds to A rather than C
C) changes the binding affinity of G
D) changes the binding affinity of T
E) creates pyrimidine dimers

Answer 24

A) replaces a T and binds to G rather than A

Question 25

Genes within an operon:
A) Tend to be regulated by a common regulatory mechanism.
B) Are generally involved in the same biochemical pathway.
C) Are expressed as a polycistronic mRNA.
D) All of the above
E) None of the above

Answer 25

D) All of the above

Question 26

The lac repressor…
A) binds to the operator in the Lac operon
B) binds lactose
C) binds glucose
D) A and B are correct
E) A, B, and C are correct

Answer 26

D) A and B are correct

Question 27

Which of the following would you expect to find in an inducible system?
A) A repressor protein, which is bound to DNA in the absence of any other factor.
B) A repressor protein, which is bound to DNA in the presence of a corepressor.
C) An activator protein, which is bound to DNA in absence of any other factor.
D) An activator protein, which is bound to DNA only in the absence of an inhibitor.
E) None of the above

Answer 27

A) A repressor protein, which is bound to DNA in the absence of any other factor.

Question 28

In the trp operon, what happens to the trp repressor in the absence of tryptophan?
A) It binds to the operator and represses transcription.
B) In cannot bind the operator, and transcription takes place.
C) It binds to the repressor gene and represses transcription.
D) In cannot bind the repressor gene, and transcription takes place.
E) It bind to RNA polymerase and represses transcription.

Answer 28

B) In cannot bind the operator, and transcription takes place.

Question 29

A mutation prevents the catabolite activator protein (CAP) from binding to the promoter in the lac
operon. What will the effect of this mutation be on the transcription of the operon?
A) RNA polymerase will bind efficiently and transcribe the operon to its highest level.
B) RNA polymerase cannot bind the lac promoter, and transcription will be absent.
C) The lac repressor will bind to the operator and transcription will be repressed.
D) Excess cAMP will inhibit transcription by RNA polymerase.
E) RNA polymerase will bind the lac promoter poorly, significantly decreasing transcription.

Answer 29

E) RNA polymerase will bind the lac promoter poorly, significantly decreasing transcription.

Question 30

DNA sites bound by regulatory transcription factors:
A) Are trans acting factors.
B) Are cis acting elements.
C) Are promoters.
D) Have similar sequences in all cells.
E) None of the above.

Answer 30

B) Are cis acting elements.

Question 31

What would be the effect on basal transcription if the TATA box were mutated?
A) The basal transcription level would be elevated.
B) Transcription would proceed but would shut off soon after initiation.
C) No effect on transcription would be observed.
D) Transcription would be reduced, perhaps to zero.
E) RNA polymerase will bind strongly to the promoter.

Answer 31

D) Transcription would be reduced, perhaps to zero.

Question 32

What is an advantage of alternative splicing?
A) Multiple genes can encode the same protein
B) The same gene can encode multiple proteins
C) The same protein can be digested in multiple ways
D) all of the above
E) none of the above

Answer 32

B) The same gene can encode multiple proteins

Question 33

Which of the following is NOT TRUE about mitosis and meiosis?
A.) homologous chromosomes pair during meiosis, but not mitosis
B.) the number of chromosomes is reduced from diploid to haploid during meiosis, but not during mitosis
C.) crossing over between non-sister chromatids occurs during meiosis, but not during mitosis
D.) meiosis results in two diploid daughter cells, but mitosis does not
E.) There are two rounds of division during meiosis, but only one during mitosis

Answer 33

D.) meiosis results in two diploid daughter cells, but mitosis does not

Question 34

Which of the following statements correctly describes a pair of homologous chromosomes?
A.) they carry different genes
B.) they may have different centromere positions
C.) they carry the same genes, and the same alleles
D.) they may carry different alleles of the same gene
E.) none of the above are correct

Answer 34

D.) they may carry different alleles of the same gene

Question 35

Which of the following occurs during anaphase I of meiosis?
A.) DNA replication occurs
B.) crossing-over occurs between non-sister chromatids
C.) sister chromatids separate from each other
D.) tetrads separate and dyads migrate to opposite poles
E.) tetrads align at the middle of the cell

Answer 35

D.) tetrads separate and dyads migrate to opposite poles

Question 36

House flies (Musca domestica) are diploid (2n=12). How many chromosomes will be present in a gamete produced by a house fly?
A.) 2
B.) 4
C.) 6
D.) 12
E.) 24

Answer 36

C.) 6

Question 37

In a cross between two monohybrid (heterozygous for one gene) individuals, we expect ______ of the progeny to exhibit the recessive phenotype.
A.) none
B.) 1/4
C.) 1/2
D.) 3/4
E.) all

Answer 37

B.) 1/4

Question 38

Traits (or phenotype) whose inheritance is consistent with mendel’s postulates are said to exhibit a _____ pattern of inheritance.
A.) sex dependent
B.) mutant
C.) mendelian
D.) darwinian
E.) recessive

Answer 38

C.) mendelian

Question 39

Pea plants which are heterozygous for the tall and dwarf stem height alleles (Dd) will produce gametes of which of the following genotypes).
A.) DD, Dd, and dd
B.) D and d
C.) Dd only
D.) D only
E.) d only

Answer 39

B.) D and d

Question 40

A testcross is a method to determine whether an individual displaying the dominant phenotype has a _____ genotype.
A.) dominant or recessive
B.) homozygous dominant or heterozygous
C.) homozygous recessive or heterozygous
D.) homozygous dominant or homozygous recessive
E.) heterozygous dominant or heterozygous recessive

Answer 40

B.) homozygous dominant or heterozygous

Question 41

Which of the following is the typical phenotypic ratio seen in the F2 generation of a dihybrid cross?
A.) 1:2:1
B.) 3:1
C.) 9:3:3:1
D.) 50:50
E.) 1:1:1:1

Answer 41

C.) 9:3:3:1

Question 42

Individuals that are heterozygous for two genes can produce ______ different gamete types?
A.) 1
B.) 2
C.) 3
D.) 4
E.) 5

Answer 42

D.) 4

Question 43

Individuals that are heterozygous for two genes can produce ______ different gamete types?
A.) 1
B.) 2
C.) 3
D.) 4
E.) 5

Answer 43

D.) 4

Question 44

Brown coat color in labrador retrievers is a recessive Mendelian trait (black coat color is dominant). If two black labs are mated and produce a brown puppy, what is the probability that the next puppy they produce will also have a brown coat?
A.) 0%
B.) 25%
C.) 50%
D.) 75%
E.) 100%

Answer 44

B.) 25%

Question 45

Mendel observed that full pea pod shape is dominant over constricted pea pod shape, and green pea pod color is dominant over yellow. From a cross between two plants with constricted yellow pea pods, what proportion of the progeny will have pea pods that are full and green?
A.) 0/16
B.) 1/16
C.) 3/16
D.) 9/16
E.) there is not enough information to answer this question

Answer 45

A.) 0/16

Question 46

How many Barr bodies would you expect to observe in a cell from a human with the Karyotype 46, XX?
A.) zero
B.) one
C.) two
D.) three
E.) some cells will have one Barr body, and some cells will have none

Answer 46

B.) one

Question 47

Which of the following is NOT true of the human X and Y chromosomes?
A.) X and Y act like a homologous pair during meiosis
B.) genes located in the pseudoautosomal regions (PARs) are present on both X and Y
C.) the SRY gene is present on the Y but not on the X
D.) X and Y are both sex chromosomes
E.) X and Y are both inactivated as Barr bodies in XXY individuals

Answer 47

E.) X and Y are both inactivated as Barr bodies in XXY individuals

Question 48

If you were to perform a cross between true-breeding red-eyed Drosophila females and true-breeding white-eyed Drosophila males, which of the following would you expect to observe in the offspring?
A.) all of the female offspring would have white eyes and all of the male offspring would have red eyes
B.) all of the female offspring would have red eyes and all of the male offspring would have white eyes
C.) all of the male and female offspring would have white eyes
D.) all of the male and female offspring would have red eyes
E.) the offspring would be 25% red eye females, 25% white eye females, 25% red eye males, and 25% white eye males

Answer 48

D.) all of the male and female offspring would have red eyes

Question 49

In crocodiles, sex is determined by the temperature at which an egg is incubated. This is an example of _____
A.) environmental sex determination (ESD)
B.) genotypic sex determination (GSD)
C.) X-Chromosome inactivation
D.) isogamy
E.) dosage compensation

Answer 49

A.) environmental sex determination (ESD)

Question 50

Helen and Frank are partners who are both carriers for the same recessive genetic disease. They have three children already, none of whom are affected by this genetic disease. If they have another child together, what is the probability that this child will be affected by the disease?
A.) 0%
B.) 25%
C.) 50%
D.) 75%
E.) 100%

Answer 50

B.) 25%

Question 51

Questions 2 and 3 of Quiz #13, have pictures

Answer 51

2.)C 3.)E

Question 52

Which of the following is true of dominant traits?
A.) they usually skip generations in human pedigrees
B.) they can only be caused by autosomal genes
C.) they affect males more frequently than females
D.) two unaffected parents should not have any affected offspring
E.) they cannot be analyzed by using pedigrees

Answer 52

D.) two unaffected parents should not have any affected offspring

Question 53

Genes that exhibit genetic linkage violate which of Mendel’s postulates?
A.) unit factors occur in pairs
B.) Dominace/Recessiveness
C.) Segregation of alleles
D.) Independent Assortment

Answer 53

D.) Independent Assortment

Question 54

Which of the following genotypes could be used to describe an individual that is heterozygous for two genes that are DIFFERENT chromosomes?
A.) Aa/Bb
B.) A/a; B/b
C.) A;a/B;b
D.) Ab/aB

Answer 54

B.) A/a; B/b

Question 55

Which of the following genotypes could be used to describe an individual that is heterozygous for two genes that are located on the SAME chromosome?
A.) Aa/Bb
B.) A/a; B/b
C.) A;a/B;b
D.) Ab/aB

Answer 55

D.) Ab/aB

Question 56

If crossing over never occurred,______
A.) genes on the same chromosomes would never assort independently
B.) genes would never exhibit linkage
C.) 100% of gametes would have a recombinant genotype
D.) meiosis and mitosis would be the same
E.) males would be XX instead of XY

Answer 56

A.) genes on the same chromosomes would never assort independently

Question 57

Flower color in snapdragons is an example of which genetic phenomenon?
A.) Complete Dominance
B.) Co-Dominance
C.) Incomplete Dominance
D.) X-Linked Inheritance
E.) Gene Linkage

Answer 57

C.) Incomplete Dominance

Question 58

The A and B blood type alleles in humans are an example of which genetic phenomenon?
A.) Complete Dominance
B.) Co-Dominance
C.) Incomplete Dominance
D.) X-Linked Inheritance
E.) Gene Linkage

Answer 58

B.) Co-Dominance

Question 59

Consider two people with blood type AB, who are both carriers of the recessive allele for albinism. What is the probability of their first child displaying the albino phenotype and blood type B?
A.) 1/16
B.) 2/16
C.) 3/16
D.) 4/16
E.) 9/16

Answer 59

A.) 1/16

Question 60

From a cross between two pink snapdragon plants, what proportion of the offspring will have pink flowers?
A.) 100%
B.) 75%
C.) 50%
D.) 25%
E.) 0%

Answer 60

C.) 50%

Question 61

In recessive epistasis, the recessive phenotype of the ____ gene prevents the phenotypic expression of the _____ gene.
A.) dominant, recessive
B.) recessive, dominant
C.) linked, unlinked
D.) epistatic, hypostatic
E.) hypostatic, epistatic

Answer 61

D.) epistatic, hypostatic

Question 62

In labrador retrievers, there is recessive epistasis between the E and B genes, both of which influences coat color. From a cross between two dihybrid labs (BbEe). What proportion of the offspring should have yellow coats?
A.) all of the puppies should have yellow coats
B.) 9/16
C.) 3/16
D.) 1/16
E.) 4/16

Answer 62

E.) 4/16

Question 63

A person with blood type O ____
A.) produces both A and B red blood cell antigens
B.) is homozygous for the recessive i allele
C.) might be homozygous for the dominant i allele
D.) is homozygous for the recessive h allele and lacks the H substance
E.) either B or D are possible for a person with blood type O

Answer 63

E.) either B or D are possible for a person with blood type O

Question 64

Two loss of function mutations that are allelic to one another ____.
A.) should fail to complement each other in a complementation test
B.) will exhibit recessive epistasis
C.) must affect two different genes
D.) will only produce wild type offspring if homozygous individuals are crossed with each other
E.) all of the above

Answer 64

A.) should fail to complement each other in a complementation test