Smartbook CH. 9 Flashcards
The genome of a cell is entirely composed of the macromolecule known as
DNA
Eukaryotic chromosomes are composed of
DNA
Genes are made up of ______, a macromolecule made up of nucleotides.
DNA
An organism’s genetic makeup is referred to as its ________, whereas the expression of those genes is referred to as the organism’s _______.
genotype, phenotype
In a chromosome, the DNA is composed of ____ strands.
2
The genome of a prokaryotic or eukaryotic cell includes DNA found in which sites?
Mitochondria
Plasmids
Chloroplast
Chromosomes
A _______ is the basic unit of DNA structure.
nucleotide
A ______ is a discrete cellular structure composed of a neatly packaged DNA molecule.
chromosome
Which component of DNA determines the 3’ and 5’ ends of the strands?
Carbons in the deoxyribose sugar.
A ______ is a sequence of DNA nucleotides that codes for one functional protein or RNA.
gene
The DNA of a chromosome is ______- stranded.
double-stranded
If one strand of DNA reads 5’-AAGCGTTA-3’, the complementary sequence would be 3’__________5’.
TTCGCAAT
In DNA, the two strands of the helix are arranged in ______ orientation.
antiparallel
A nucleotide is oriented 5’ or 3’ depending on the location of the _______ on the strand of DNA.
deoxyribose carbons
Before a bacterial cell can undergo binary fission, the _____ must be duplicated.
DNA
The enzymes responsible for building the DNA strand, proofreading newly produced DNA strands, and removing the RNA primer are DNA _____ I and III.
polymerase
During _____ DNA replication , the newly made double helices are composed of one parent template and one newly synthesized strand.
semiconservative
Which best describes the antiparallel orientation of strands in DNA?
One strand is 5’ to 3’ and the other is 3’ to 5’.
The place where DNA replication is initiated is called the _____.
origin of replication
True or false: During DNA replication, both the leading and lagging strands are synthesized in the 5’ to 3’ direction.
true
What must be replicated before a cell can divide through binary fission.
genetic material
Unzips the DNA helix prior to the start of replication
helicase
DNA polymerases are responsible for
proofreading/repair.
building the DNA chain.
Each new DNA helix contains one parent strand and one newly synthesized strand
true
The replication _____ is the Y-shaped point on a replicating DNA molecule where the DNA polymerase is synthesizing new strands of DNA.
replication fork
The site on a chromosome where DNA replication begins is called the
origin of replication
DNA polymerase synthesizes DNA strands in the 5’ to 3’ direction
True
The leading strand is replicated continuously without segments during DNA replication.
true
The newly forming DNA strand that is discontinuously replicated in segments (Okazaki fragments) is called the
lagging strand
How many replication forks are formed from opening a section of a circular DNA molecule during replication?
2
The flow of genetic information in a cell is a process starting with
DNA which encodes RNA which encodes protein
During ____, the information in mRNA is used to produce a protein.
translation
_____ is the process of decoding DNA into messenger RNA.
transcription
Which strand is replicated discontinuously in segments during DNA replication?
lagging
A codon contains how many nucleotides?
3
_____ fragments are formed during DNA replication of the lagging strand.
Okazaki
Which organic molecule is formed from chains of amino acids?
proteins
The DNA blueprint specifies how to make what type of macromolecule?
Proteins
During which process is mRNA converted into a protein?
translation
Which of the following describes the primary structure of a protein?
The chain of amino acids bound by peptide bonds
During transcription, RNA polymerase synthesizes ______ from a(n) ______ template.
RNA; DNA
Proteins contribute to the phenotype of an organism by functioning as
enzymes.
structural molecules.
is the specific sequence of 3 mRNA nucleotides, based on a DNA triplet, that encodes a particular amino acid.
codon
a sequence of three nucleotides which together form a unit of genetic code in a DNA or RNA molecule.
codon
How does RNA differ from DNA in bacteria and eukaryotes?
In RNA, uracil replaces thymine
RNA is single-stranded
are functional biomolecules in cells formed from one or more long chains of amino acids.
proteins
_______ RNA brings the amino acids to the ribosome.
transfer
The “blueprint” information for the production of proteins is permanently encoded in sections of
DNA
Which molecule contains the codons for the polypeptide?
mRNA
The specific order of amino acids bound to each other by peptide bonds represents the _____ structure of a protein.
primary
True or false: Proteins contribute to the phenotype of an organism.
true
The ribosome, composed of rRNA and protein, is involved in the process of
translation
Unlike DNA, RNA contains the nitrogenous base
uracil
Which of the following are functions of RNA polymerase?
Unwinds the DNA so that transcription can take place
Synthesizes an RNA molecule from DNA template
What is the function of tRNA?
Brings amino acids to the ribosome
_____ RNA contains the codons for the polypeptide.
messenger
What is the correct order of events in transcription?
- Initiation
- Elongation
- Termination
Which of the following describes the primary structure of a protein?
The chain of amino acids bound by peptide bonds.
The prokaryotic ribosome is composed of ______ and protein.
rRNA (ribosomal RNA)
RNA polymerase binds to the _____ region to initiate transcription.
promoter
The main enzyme responsible for transcription is
RNA polymerase.
During transcription, RNA is built using RNA polymerase. DNA polymerase is involved in replication of DNA.
Transcription involves initiation, _____ , and termination.
elongation
True or false: Several codons code for the same amino acid, which is called the redundancy of the code.
true
If a codon of mRNA reads 5’-UUG-3’, the tRNA that delivers the amino acid to this location during translation will have an anticodon of 3’-_____-5’.
AAC
What amino acid sequence is encoded by the DNA template sequence 3’-TACCGCGCTCTACCG-5’? (Look up the genetic code figure in your textbook.)
Methionine-Alanine-Arginine-Aspartic Acid-Glycine
The mRNA sequence AUG, specifying the first amino acid in protein sequences, is called the
start codon
The first three events of translation in the correct order are ____,____,____ followed by protein folding and processing.
initiation
elongation
termination
True or false: A mutation is an alteration in the DNA sequence or content of a cell that is passed on when the cell divides.
true
The _____ of the genetic code results in several codons encoding the same amino acid.
redundancy or degeneracy
_____ mutations in DNA are caused by random mistakes in replication and not known to be influenced by any mutagenic agent.
Spontaneous
If the DNA sequence is known the mRNA codon can be surmised.
If a codon is known, the anticodon and the amino acid sequence can be determined.
The ____ of a tRNA is complimentary to a _____ of mRNA.
anticodon
codon
What type of DNA mutation occurs as a consequence of exposure to chemical or physical mutagens?
induced
Which template DNA sequence encodes the peptide sequence phenylalanine-leucine-aspartic acid-valine? (Look up the genetic code figure in your textbook)
3’-AAAAACCTACAT-5’
An agent that induces changes in DNA is a(n)
mutagen
The _____ codon AUG of mRNA is associated with the tRNA anticodon UAC and the amino acid methionine.
start
The main effect of ultraviolet radiation on DNA is abnormal bonding between adjacent ________.
pyrimidines
A permanent inheritable alteration in the DNA sequence of a cell is a(n)
mutation
Mutations that involve the addition, deletion or substitution of one or a few bases are referred to as _______ mutations.
point
A ______ mutation results in early termination of the protein.
nonsense
A missense mutation encodes a functional
amino acid
A silent mutation changes the
DNA sequence
A _____ mutation results in a different amino acid being incorporated into a protein, with varying results.
missense
Which is an agent that induces changes in DNA?
mutagen
Which mutation changes an amino acid producing codon into a stop codon?
Nonsense
What is the main effect of ultraviolet radiation on DNA?
Abnormal bonding between adjacent pyrimidines
A _____ mutation results from an insertion or deletion of nucleotides in multiples of 1 or 2, leading to a shift of the triplet sequence from the point of mutation downstream.
frameshift mutation
Mutations that involve the addition, deletion or substitution of no more than a few bases are referred to as
point mutations
Which type of mutation is generally most harmful to cells?
Frameshift mutation
What is the result of a point mutation that changes a template gene sequence from 3’-TACGCCATATAT-5’ to 3’-TACGCCATCTAT-5’?
Nonsense mutation
True or false: Mutations are always harmful to cells.
false
Which type of mutation results in a different amino acid being incorporated into a protein?
Missense
A _____ mutation changes an amino-acid-producing codon into a stop codon, leading to premature termination of a protein.
nonsense
Which term refers to the transfer of genes from donor to recipient microorganisms?
Recombination
True or false: A point mutation results from an insertion or deletion of nucleotides, and always leads to a shift of the triplet sequence from the point of mutation downstream.
false
A frameshift mutation involves a shift of the triplet sequence from the point of mutation downstream.
A recombinant is any organism that has
acquired genes that originated in another organism.
_____ mutations are generally most harmful to cells because they cause the greatest change in the amino acid sequence of a protein.
frameshift
What is a small circular segment of DNA found in the cytoplasm of prokaryotes that is capable of independent replication and usually contains nonessential genes?
plasmid
A small number of _____ are considered beneficial in that they provide the cell with a useful change in structure or physiology.
mutations
R factors are specifically associated with which mechanism of recombination?
Conjugation
R factors are plasmids that carry resistance genes through conjugation
_____ in bacteria refers to horizontal gene transmission via pili.
conjugation
_____ refers to the transfer of genes from donor to recipient microorganisms, where the recipient strain shows a change in genetic makeup at the end.
Recombination
Conjugation in gram-negative cells is directed by a plasmid called the
fertility factor
A(n) _______ is any organism that has acquired genes that originated in another organism.
recombinant
True or false: A cell with an integrated F factor transmits its genes at lower frequency than does a cell with a free plasmid in the cytoplasm.
false
Cells with integrated plasmids are denoted as Hfr, or high frequency recombination, for their ability to transmit chromosomal genes at higher rates than other cells.
A _____ is a small circular segment of DNA found in the cytoplasm of bacteria that is capable of independent replication and usually contains nonessential genes.
plasmid
True or false: R-factors or “resistance factors” can be shared between bacteria through conjugation to help them survive the effects of antibiotics.
true , The “R” in R-factor stands for resistance, referring to resistance to antibiotics.
During which method of gene transfer are bacterial cells in direct contact?
conjugation
During transformation, competent recipient cells can uptake free DNA from the environment
During transduction, bacteriophages carry DNA from donor to recipient bacterial cells
Griffith’s experiment using Streptococcus pneumoniae demonstrated the process of _______.
transformation
True or false: Bacterial conjugation is a sexual process.
false
What is the name of the specialized plasmid that directs conjugation in gram-negative cells?
f factor
_____ involves the uptake of free DNA by competent bacterial cells.
transformation
How do an Hfr cell and an F+ cell differ?
The plasmid is integrated into the chromosome of an Hfr cell but not in an F+ cell.
Which type of plasmids confer the ability of an organism to survive treatment by antibiotics?
R factors
_____ involves the transfer of DNA via bacteriophages.
transduction
What did Griffith’s experiment using Streptococcus pneumoniae demonstrate?
That two different strains of S. pneumoniae transformed into a third unique and virulent strain
A ________ serves as the vector for transduction in bacteria.
phage
Which recombination method involves transfer of DNA via bacteriophages?
Transduction
Transduction occurs through
a bacteriophage.
