1Cinnabar eye is a sex-linked recessive characteristic in fruit flies. If females having cinnabar eyes are crossed with wild-type males, what percentage of the F1 males will express cinnabar eyes?
2Which of the following human genetic diseases show pleiotropy?
- albinism
- red-green colorblindness
- sickle cell anemia
- male pattern baldness
- muscular dystrophy
3Which of the following statements describe homologous chromosomes?
- a pair of chromosomes that segregate from each other at anaphase II of meiosis
- a pair of chromosomes containing the same gene loci in the same order but may have different alleles at identical loci
- a pair of sister chromatids attached by a centrome
- a pair of chromosomes attached by a centrome
- they are genetically identical
4Which are possible gamete genotypes produced by sexually reproducing animal with two unlinked genes forming a genotype of HhTt for head shape (H) and one for long tail (T)?
5Which of the following statements describes the process of transformation in bacteria?
- a strand of DNA is created from an RNA molecule
- a strand of RNA is created from a DNA molecule
- bacterial cells are infected by a phage DNA molecule
- DNA in the environment is taken up by bacteria to become part of the bacteria's genome
- heat killed bacteria can be converted to living cells
6When cytosine makes up 42% of the nucleotides in a sample of DNA, approximately what percentage of the nucleotides in this sample will be thymine?
7Which characteristics of DNA code for the vast amount of hereditary information in DNA?
- the bonded sequence of deoxyribonucleotide purines and pyrimidine on a DNA template chain
- the bonded sequence of phosphates to sugars in the backbones of DNA
- the complimentary pairing of purines and pyrimidines
- the side groups of purines and pyrimidines
- the sequence of RNA primers along a DNA chain
8During the DNA synthesis free deoxyribonucleotides are bonded by phosphodiester bonds, which are formed between the nucleotides phosphate group and which component of the end nucleotide of the new growing DNA chain?
- the 5-prime phosphate group of the deoxyribose
- carbon number 6 of the deoxyribose
- the 3-prime hydroxyl (OH) group on deoxyribose
- the nitrogen of the base (either purine or pyrimidine)
- carbon number 1 on deoxyribose
9Which reactions cannot occur in E. coli bacteria containing a mutation in gene dnaB which alters helicase catalyzed reactions?
- additional proofreading will occur
- no replication fork will be formed
- replication will occur via RNA polymerase alone
- replication will require a DNA template from another source
- the double helix structure of DNA will breakdown
10In E. coli bacteria, which enzyme catalyzes the elongation of a new DNA strand?
- primase
- DNA ligase
- DNA polymerase III
- helicase
- RNA polymerase
11At a specific area of a chromosome, the sequence of nucleotides below is present where the chain opens to form a replication fork: 3' C C T A G G C |T| G C A A T C C 5' a RNA primer is formed starting at the underlined T of the template. Which of the following represents the possible primer sequence?
- 5' G C C T A G G 3'
- 5' A C G T T A G G 3'
- 5' A C G U U A G G 3'
- 5' G C C U A G G 3'
12In analyzing the number of different bases in a DNA sample, which result would be consistient with the base-pairing rules?
13Bacteria repair a thymine dimmer by nucleotide excision repair, in which order do the necessary enzymes act?
a. nuclease, DNA polymerase, RNA primase
b. helicase, DNA polymerase, DNA ligase
c. DNA ligase, nuclease, helicase
d. nuclease, DNA polymerase, DNA ligase
e. DNA ligase, DNA polymerase, nuclease
- nuclease, DNA polymerase, RNA primase
- helicase, DNA polymerase, DNA ligase
- DNA ligase, nuclease, helicase
- nuclease, DNA polymerase, DNA ligase
- DNA ligase, DNA polymerase, nuclease
14Which statement correctly describes the difference between the DNA replication of the leading and lagging strands?
- the leading strand is synthesized in the same direction as the opening of the replication fork, and the lagging strand is synthesized in the opposite direction
- the leading strand is synthesized by adding nucleotides to the 3' end of the growing strand, and the lagging strand is synthesized by adding nucleotides to the 5' end
- the lagging strand is synthesized continuously, whereas the leading strand is synthesized in short fragments that are ultimately stitched together
- the leading strand is synthesized at twice the rate of the lagging strand
15Which statements correctly describes the difference between ATP required for metabolism and the ATP nucleotides required for DNA synthesis in cells?
a. the dATP required for DNA replication have the sugar deoxyribose whereas ATP is a ribonucleotide containing the sugar ribose
b. the nucleotides have 2 phosphate groups; ATP has 3 phosphate groups
c. ATP contains 3 high-energy bonds; the deoxyribonucleotides have 2
d. ATP is found only in human cells; the nucleotides are found in all animal and plant cells
e. ATP is produced in the mitochondria and the ATP deoxyribonucleotide is produced in the nucleus
- the dATP required for DNA replication have the sugar deoxyribose whereas ATP is a ribonucleotide containing the sugar ribose
- the nucleotides have 2 phosphate groups; ATP has 3 phosphate groups
- ATP contains 3 high-energy bonds; the deoxyribonucleotides have 2
- ATP is found only in human cells; the nucleotides are found in all animal and plant cells
- ATP is produced in the mitochondria and the ATP deoxyribonucleotide is produced in the nucleus
16What is the role of DNA ligase in the elongation of the lagging strand during DNA replication?
- it synthesizes RNA nucleotides to make a primer
- it bonds the DNA of 2 Okazaki fragments
- it unwinds the parental double helix
- it stabilizes the unwound parental DNA
- it catalyzes the cutting DNA at specific sites to separate 2 DNA molecules
17In a nucleosome, the DNA is wrapped around which of the following?
- histones
- ribosomes
- polymerase molecules
- thymine dimer
18During which of the following stages of meiosis are homologous chromosomes separated?
- metaphase I
- anaphase I
- metaphase II
- anaphase II
- telophase II
19During which of the following stages of meiosis are sister chromatids separated?
- metaphase I
- anaphase I
- metaphase II
- anaphase II
- telophase II
20Which of the following is the function of eukaryotic nucleosomes?
- regulation of gene expression by inactivating genes wrapped around them
- regulation of gene expression by selectively binding active transcription factors
- regulate gene expression by using its histone proteins to catalyze alternative splicing of the pre-mRNA
- promote transcription of genes wrapped around the histone proteins
- all of the above answers are correct
21Which of the following is the most accurate definition of a gene?
- a DNA sequence that carries information to produce a specific RNA
- a DNA nucleotide sequence that carries information to produce a specific polypeptide
- a DNA or RNA sequence that carries information to produce a single polypeptide
- a DNA nucleotide sequence that carries information to produce an enzyme
- a DNA or RNA sequence that carries information to produce a specific protein
22Initiation of transcription requires which of the following?
- a promoter sequence
- DNA polymerase
- an RNA primer
- DNA primer
- Okazaki fragments
23Which of the following enzymes can be guided to bind to a specific DNA promoter to catalyze separation of the template chain from the complementary chain to start the synthesis of RNA complementary and antiparallel to the template?
- DNA polymerase I
- DNA polymerase II
- DNA polymerase III
- RNA polymerase
- DNA ligase
24Which of the following are the substrates for transcription catalyzed by RNA polymerase?
- deoxyribo-ATP, dGTP, dCTP, dUTP and a DNA template
- the 20 different types of amino acids, tRNAs and a DNA template
- ATP, GTP, CTP, UTP and a DNA template
- a single DNA template chain and deoxyribonucleotide triphosphates
- rRNA, tRNA and amino acids
25RNA synthesis occurs in which of the following directions?
- 5' --> 3'
- 3' --> 5'
- 5' --> 2'
- 2' --> 5’
- none of the choices are correct
26The genetic code of a mRNA chain occurs in which of the following directions?
- 5' --> 3'
- 3' --> 5'
- 5' -->2'
- 2' --> 5'
- amino acid --> carboxyl end
27What usually occurs when DNA sequences are methylated in eukaryotic cells?
- repressed from being expressed
- actively expressed
- mutated
- always expressed
- are not replicated
28If the A and B gene loci are linked on the same chromosome but separated by 100 map units. What percent of the progeny from the cross of a heterozygous (AB/ab) parent and a homozygous recessive parent (ab/ab) would show the recombinant (aB/ab and Ab/ab) phenotype due to crossing over between loci A and B?
29Which is formed when a X-chromosome in the cell nucleus of female mammals become inactive?
- complexed with repressor molecules
- heterochromatin
- euchromatin
- replicated
- active X-factor
30Which occurs to DNA sequences that are methylated in eukaryotic cells?
- they can be repressed so they cannot be expressed
- they can be actively expressed
- they can become mutated
- they are constitutive so their genes can be expressed
- their DNA cannot be replicated
31In an animal species, gene A and gene B loci are separated on the same chromosome by 100 map units. What fraction of the progeny from the cross of a heterozygous (AB/ab) parent and a homozygous recessive parent (ab/ab) would show the dominate parental phenotypes (A_B_) if no crossing over occurred between loci A and B?
32Which of the following describes the concept of nuclear equivalence in the somatic cells of animals as development occurs?
- the gene alleles of the individuals of the same species are exactly the same
- all somatic cells in the different types of tissues of an organism have the same gene loci and alleles but only specific loci are expressed in specific cell types
- as cells mature, unneeded genes are lost
- the nuclei of al eukaryotic organisms are the same
- all of the somatic cells in the different types of tissues of an organism express the same gene alleles
33In eukaryotic cells, transcription cannot begin until which of the following occurs?
- the 2 DNA strands have completely separated and exposed the promoter
- several transcription factors have bound to the promoter and the enchancer of the gene
- the 5' caps are removed from the mRNA
- the DNA introns are removed from the template
- DNA nucleases have isolated the transcription unit
34How does the pre-mRNA transcript in the nucleus of a eukaryotic cell compare with the mRNA in the cytoplasm?
- the pre-mRNA transcript is the same size as the mRNA
- the pre-mRNA transcript is longer than the mRNA
- the pre-mRNA transcript is smaller than the mRNA
- both the pre-mRNA functional transcript and mRNA contain introns
- the functional mRNA is degraded as soon as it reaches the cytoplasm
35How do we describe transformation in bacteria?
- the creation of a strand of DNA from an RNA molecule
- the creation of a strand of RNA from a DNA molecule
- the infection of cells by a phage DNA molecule
- the uptake of foreign external DNA from the environment and incorporating it into the cell's DNA
36Which of the following functions are characteristic of general transcription factors in eukaryotes?
- they bind to other proteins or to the TATA box
- they inhibit RNA polymerase binding to the promoter and begin transcribing
- they usually lead to a high level of transcription event without additional specific transcription factors
- they bind to sequences just after the start site of transcription
37A particular triplet of nucleotide bases in the coding sequence of DNA is TAC. The anticodon on the tRNA that binds the mRNA codon of AUG is which of the following?
38Which of the following processes occurs during transcription?
- DNA is replicated
- RNA is synthesized
- proteins are synthesized
- ribosomes attach to mRNA and synthesize polypeptides
- the activation of inactive proteins in the cytoplasm
39During the initiation of transcription in eukaryotic cells, which proteins bind to the specific promoter to facilitate the binding of RNA polymerase II to the promoter sequence so that it can initiate transcription of the gene?
- transcriptional factors
- primase
- RNA polymerase
- DNA polymerase
- helicase
40Which of the following enzymes attaches to one of the single DNA template chains at a replication fork and synthesize a short primer molecule that is antiparallel, complementary, and hydrogen bonded to the DNA template?
- primase
- helicase
- to poison erase
- DNA polymerase III
- RNA polymerase
41When a dihybrid (Y+y E+e) wild type Drosophilia is test crossed with fruit flies that have recessive yellow eyes (y) and recessive earth wings (e) the following offspring were produced:
474 wild type eyes and wild type wings
476 yellow eyes and earth wings
26 wild type eyes and earth wings
24 yellow eyes and wild type wings
1000
What is the map distance between locus Y and locus E?
- 95 map units
- 47.5 map units
- 26 map units
- 50 map units
- 5 map units