BIOLOGY 1306 CORE MAIN QUESTIONS AND
ANSWERS SET A+
✔✔Identify the stage of mitosis shown in panel B. - ✔✔anaphase
✔✔Meiosis occurs in the ____. - ✔✔gonads
✔✔Match the five types of allele effects listed below with the correct example. -
✔✔wrinkled vs. round peas = dominance,
human AB blood type = codominance,
snapdragon flower color (red, pink, and white) = incomplete dominance,
human height = polygenic inheritance,
Labrador retriever fur color (black, chocolate brown, yellow) = epistasis
✔✔Which genetic character is an example of epistasis? - ✔✔Labrador Retriever fur
color
✔✔The tight packing of chromatin into the chromosomes visible during nuclear division
is possible due to links between ____ proteins. - ✔✔H1 histone
✔✔Replication of DNA occurs during ____. - ✔✔S phase
✔✔Identify the stage of mitosis shown in panel D. - ✔✔telophase
✔✔Karyotype analyses are performed on cells in ____ of mitosis. - ✔✔metaphase
✔✔DNA replication occurs ____. - ✔✔during interphase before meiosis
✔✔Where is the centromere found? - ✔✔central region of a chromosome where the
spindle microtubules attach
,✔✔The change in the chromosome depicted between the top and the bottom in the
accompanying figure represents a(n) ____. - ✔✔duplication
✔✔An autosome is a ____. - ✔✔chromosome other than a sex chromosome
✔✔When two pairs of homologous chromosomes join for crossing-over, the complex is
called a ____. - ✔✔tetrad
✔✔A continuous distribution of characters such as height, body weight, or skin color is
usually the result of _____. - ✔✔polygenic inheritance
✔✔The genome of an organism contains 14% guanine; therefore, its genome also
contains ____% thymine and ____% cytosine. - ✔✔36; 14
✔✔The TP53 gene codes for a transcription factor that turns on the expression of cell
division inhibiting proteins, therefore the TP53 gene is a _____. - ✔✔tumor suppressor
gene
✔✔The role of a tumor suppressor protein in a cell is to ____. - ✔✔inhibit cell growth
and division
✔✔Methylation regulates transcription by ____. - ✔✔adding a methyl group to cytosine
bases of DNA
✔✔Cultures of genetically identical cells are called ____. - ✔✔clones
✔✔In the process of quorum sensing, bacteria release signaling molecules in ____
concentrations as cell density ____. - ✔✔increasing; increases
✔✔What is the function of the sliding clamp in DNA replication? - ✔✔anchor DNA
polymerase to the template strand
✔✔During DNA replication, what determines the sequence of the bases in the new DNA
strand? - ✔✔the sequence of bases in the template strand
✔✔Many breast cancers are associated with mutations in the BRCA1 gene. Explain the
difference between sporadic and familial breast cancer caused by this gene at a
molecular level. - ✔✔In order to develop breast cancer from a mutation in the BRCA1
gene, both copies of the gene must be mutated. In sporadic breast cancer, the cell
originally has two normal copies of the gene, but over time, a mutation arises in one
copy and then the other. In familial cancer, an individual inherits one normal copy of the
gene and one mutant copy. Therefore, a cell only needs to acquire a mutation in the
one normal copy of the gene for cancer to develop.
,✔✔Helicase ____. - ✔✔unwinds the double-stranded DNA helix
✔✔In the process of mRNA splicing, _____ are removed and _____ are joined together.
- ✔✔introns; exons
✔✔Insertion of two bases into the coding region of a gene just after the start codon of a
gene will result in a ____ mutation. - ✔✔frameshift
✔✔The two strands of a DNA double helix are said to be antiparallel. This means that
____. - ✔✔the 5' end of one strand is directly paired with the 3' end of the other strand
✔✔Most polypeptides require helper proteins called _____ to fold into the correct three-
dimensional structure. - ✔✔chaperones
✔✔Which nucleotide sequence is complementary to the DNA sequence 5'-GACGTT-3'?
- ✔✔3'-CTGCAA-5'
✔✔DNA ligase closes nicks between ____ by forming ____ bonds. - ✔✔DNA
fragments; covalent
✔✔The evolution of which class of molecules played an important role in the
development of multicellular organisms? - ✔✔protein kinases
✔✔During bacterial conjugation, bacteria use a long tubular structure called a(n) ____
to contact each other. - ✔✔sex pilus
✔✔The process of translation refers to the use of information encoded in ____ to make
____. - ✔✔RNA; a polypeptide
✔✔Nucleosomes are best described as ____. - ✔✔eukaryotic DNA associated with
histone proteins
✔✔The genetic code is said to be degenerate because ____. - ✔✔most amino acids
are represented by more than one codon
✔✔The ____ , located ____ of the transcription start point, is the site at which RNA
polymerase associates with DNA to begin transcription. - ✔✔promoter; upstream
✔✔What describes a modification that occurs during pre-mRNA processing? - ✔✔a
poly(A) tail is added to the 3' end
, ✔✔With minor exceptions, the genetic code ____. - ✔✔is the same for all living
organisms and viruses
✔✔Sporadic cancers ____. - ✔✔are cancers that are not inherited
✔✔A tumor comprised of cells that invade and disrupt surrounding tissues is called a(n)
____ tumor. - ✔✔malignant
✔✔DNA replication is said to be semiconservative because ____. - ✔✔each new DNA
molecule is composed of one old strand and one new strand
✔✔Adjacent nucleotides on a strand of DNA are connected to each other by a(n) ____.
- ✔✔phosphodiester bond
✔✔Adjacent animal cells utilize ____ to rapidly communicate with each other. - ✔✔gap
junctions
✔✔The region in a tRNA molecule that base-pairs with mRNA during translation is the
____. - ✔✔anticodon
✔✔To begin transcription, the RNA polymerase recognizes a specific DNA sequence
called the _____. - ✔✔promoter
✔✔Proofreading by ____ corrects errors that occur during DNA replication. - ✔✔DNA
polymerase
✔✔The genetic material of all living organisms is ____. - ✔✔deoxyribonucleic acid
✔✔Cancer cells ____. - ✔✔maintain telomerase function
✔✔A DNA double helix has two strands that are held together by ____. - ✔✔hydrogen
bonds
✔✔Individuals with xeroderma pigmentosum inherit a faulty DNA repair mechanism. As
a consequence, ____. - ✔✔they easily develop skin cancer when exposed to sunlight
✔✔Reiji Okazaki discovered what are now called "Okazaki fragments" produced during
DNA replication. These fragments are ____. - ✔✔short lengths of new DNA on the
lagging strand
✔✔Operons regulate gene expression in _____, but not in _____. - ✔✔prokayotes;
eukaryotes
ANSWERS SET A+
✔✔Identify the stage of mitosis shown in panel B. - ✔✔anaphase
✔✔Meiosis occurs in the ____. - ✔✔gonads
✔✔Match the five types of allele effects listed below with the correct example. -
✔✔wrinkled vs. round peas = dominance,
human AB blood type = codominance,
snapdragon flower color (red, pink, and white) = incomplete dominance,
human height = polygenic inheritance,
Labrador retriever fur color (black, chocolate brown, yellow) = epistasis
✔✔Which genetic character is an example of epistasis? - ✔✔Labrador Retriever fur
color
✔✔The tight packing of chromatin into the chromosomes visible during nuclear division
is possible due to links between ____ proteins. - ✔✔H1 histone
✔✔Replication of DNA occurs during ____. - ✔✔S phase
✔✔Identify the stage of mitosis shown in panel D. - ✔✔telophase
✔✔Karyotype analyses are performed on cells in ____ of mitosis. - ✔✔metaphase
✔✔DNA replication occurs ____. - ✔✔during interphase before meiosis
✔✔Where is the centromere found? - ✔✔central region of a chromosome where the
spindle microtubules attach
,✔✔The change in the chromosome depicted between the top and the bottom in the
accompanying figure represents a(n) ____. - ✔✔duplication
✔✔An autosome is a ____. - ✔✔chromosome other than a sex chromosome
✔✔When two pairs of homologous chromosomes join for crossing-over, the complex is
called a ____. - ✔✔tetrad
✔✔A continuous distribution of characters such as height, body weight, or skin color is
usually the result of _____. - ✔✔polygenic inheritance
✔✔The genome of an organism contains 14% guanine; therefore, its genome also
contains ____% thymine and ____% cytosine. - ✔✔36; 14
✔✔The TP53 gene codes for a transcription factor that turns on the expression of cell
division inhibiting proteins, therefore the TP53 gene is a _____. - ✔✔tumor suppressor
gene
✔✔The role of a tumor suppressor protein in a cell is to ____. - ✔✔inhibit cell growth
and division
✔✔Methylation regulates transcription by ____. - ✔✔adding a methyl group to cytosine
bases of DNA
✔✔Cultures of genetically identical cells are called ____. - ✔✔clones
✔✔In the process of quorum sensing, bacteria release signaling molecules in ____
concentrations as cell density ____. - ✔✔increasing; increases
✔✔What is the function of the sliding clamp in DNA replication? - ✔✔anchor DNA
polymerase to the template strand
✔✔During DNA replication, what determines the sequence of the bases in the new DNA
strand? - ✔✔the sequence of bases in the template strand
✔✔Many breast cancers are associated with mutations in the BRCA1 gene. Explain the
difference between sporadic and familial breast cancer caused by this gene at a
molecular level. - ✔✔In order to develop breast cancer from a mutation in the BRCA1
gene, both copies of the gene must be mutated. In sporadic breast cancer, the cell
originally has two normal copies of the gene, but over time, a mutation arises in one
copy and then the other. In familial cancer, an individual inherits one normal copy of the
gene and one mutant copy. Therefore, a cell only needs to acquire a mutation in the
one normal copy of the gene for cancer to develop.
,✔✔Helicase ____. - ✔✔unwinds the double-stranded DNA helix
✔✔In the process of mRNA splicing, _____ are removed and _____ are joined together.
- ✔✔introns; exons
✔✔Insertion of two bases into the coding region of a gene just after the start codon of a
gene will result in a ____ mutation. - ✔✔frameshift
✔✔The two strands of a DNA double helix are said to be antiparallel. This means that
____. - ✔✔the 5' end of one strand is directly paired with the 3' end of the other strand
✔✔Most polypeptides require helper proteins called _____ to fold into the correct three-
dimensional structure. - ✔✔chaperones
✔✔Which nucleotide sequence is complementary to the DNA sequence 5'-GACGTT-3'?
- ✔✔3'-CTGCAA-5'
✔✔DNA ligase closes nicks between ____ by forming ____ bonds. - ✔✔DNA
fragments; covalent
✔✔The evolution of which class of molecules played an important role in the
development of multicellular organisms? - ✔✔protein kinases
✔✔During bacterial conjugation, bacteria use a long tubular structure called a(n) ____
to contact each other. - ✔✔sex pilus
✔✔The process of translation refers to the use of information encoded in ____ to make
____. - ✔✔RNA; a polypeptide
✔✔Nucleosomes are best described as ____. - ✔✔eukaryotic DNA associated with
histone proteins
✔✔The genetic code is said to be degenerate because ____. - ✔✔most amino acids
are represented by more than one codon
✔✔The ____ , located ____ of the transcription start point, is the site at which RNA
polymerase associates with DNA to begin transcription. - ✔✔promoter; upstream
✔✔What describes a modification that occurs during pre-mRNA processing? - ✔✔a
poly(A) tail is added to the 3' end
, ✔✔With minor exceptions, the genetic code ____. - ✔✔is the same for all living
organisms and viruses
✔✔Sporadic cancers ____. - ✔✔are cancers that are not inherited
✔✔A tumor comprised of cells that invade and disrupt surrounding tissues is called a(n)
____ tumor. - ✔✔malignant
✔✔DNA replication is said to be semiconservative because ____. - ✔✔each new DNA
molecule is composed of one old strand and one new strand
✔✔Adjacent nucleotides on a strand of DNA are connected to each other by a(n) ____.
- ✔✔phosphodiester bond
✔✔Adjacent animal cells utilize ____ to rapidly communicate with each other. - ✔✔gap
junctions
✔✔The region in a tRNA molecule that base-pairs with mRNA during translation is the
____. - ✔✔anticodon
✔✔To begin transcription, the RNA polymerase recognizes a specific DNA sequence
called the _____. - ✔✔promoter
✔✔Proofreading by ____ corrects errors that occur during DNA replication. - ✔✔DNA
polymerase
✔✔The genetic material of all living organisms is ____. - ✔✔deoxyribonucleic acid
✔✔Cancer cells ____. - ✔✔maintain telomerase function
✔✔A DNA double helix has two strands that are held together by ____. - ✔✔hydrogen
bonds
✔✔Individuals with xeroderma pigmentosum inherit a faulty DNA repair mechanism. As
a consequence, ____. - ✔✔they easily develop skin cancer when exposed to sunlight
✔✔Reiji Okazaki discovered what are now called "Okazaki fragments" produced during
DNA replication. These fragments are ____. - ✔✔short lengths of new DNA on the
lagging strand
✔✔Operons regulate gene expression in _____, but not in _____. - ✔✔prokayotes;
eukaryotes
