Bio test 4
An enzyme that joins RNA nucleotides to make the primer using the parental DNA strand as a template.
Primase
What local effect would an RNA synthesis inhibitor have on DNA replication?
Primase would not be able to provide primers for DNA polymerases.
Retroviruses contain as their genetic material?
RNA
transfer RNA
RNA in the cytoplasm that carries an amino acid to the ribosome and adds it to the growing protein chain
Ribosomal RNA
RNA that associates with proteins to form ribosomes
Law of Mendelian Segregation
- 2 particles of inheritance in an individual SEGREGATE from each other - each progeny receives 1 particle (gamete) from each parent
If cells in the active process of a cell cycle are subjected to ciprofloxacin, a drug that interferes with DNA synthesis, which stage of the cell cycle will most directly affected?
S phase
The cell cycle stage in which the cell may incorporate radioactive thymidine into its DNA is referred to as?
S phase
If two genes are not linked and a testcross of a completely heterozygous individual to a completely homozygous recessive individual would yield how many different progeny types?
4
TATA box
A DNA sequence in eukaryotic promoters crucial in forming the transcription initiation complex.
enhancer
A DNA sequence that recognizes certain transcription factors that can stimulate transcription of nearby genes.
missense mutation
A base-pair substitution that results in a codon that codes for a different amino acid.
DNA ligase
A linking enzyme that catalyzes the covalent bonding of the 3' end of a new DNA fragment to the 5' end of a growing chain
transcription factors
A regulatory protein that binds to DNA and affects transcription of specific genes.
primase
An enzyme that joins RNA nucleotides to make the primer using the parental DNA strand as a template.
restriction endonucleases
Bacterial enzymes that cut DNA at unique sequences along DNA molecules
Meiosis 1: Prophase 1
Crossing over occurs and synapsis (homologs pair together)
a short strand of DNA (or RNA) that serves as a starting point for DNA synthesis
DNA primer
Cell Cycle: S Phase
DNA replication
Watson and Crick
Figured out structure of DNA was a double helix
Measurements of the amount of DNA per nucleus were taken on a large number of cells from a growing fungus. The measured DNA levels ranged from 3 to 6 picograms per nucleus. In which stage of the cell cycle did the nucleus contain 6 picograms of DNA?
G2
linked genes
Genes located close enough together on a chromosome that they tend to be inherited together.
opens double helix to expose base pairs
Helacase
a F-plasmid has become integrated in the bacterial cell's genomic DNA
Hfr bacterial cell
Nondisjunction
Homologous chromosomes fail to separate during meiosis
DNA polymerase III
In charge of synthesizing nucleotides onto the leading end in the classic 5' to 3' direction.
An enzyme that connects two fragments of DNA to make a single fragment
Ligase
inversion mutation
Mutation in which a chromosome piece reattaches to original chromosome but in reverse orientation
primary transcript
The initial mRNA transcript that is transcribed from a protein coding gene
cDNA
a DNA molecules copied from a mRNA by the enzyme reverse transcriptase and therefore lacks the introns present in nuclear (genomic) DNA
reverse transcriptase
a polymerase that catalyzes the formation of DNA using RNA as a template
sigma factor
a protein that associates with RNA polymerase that facilitates its binding to specific promoters
The subcell entity or organelle-like structure that is responsible for removingintrons from a eukaryotic primary transcript is?
a spliceosome
Amino acids that are carried into the A-site (aminoacyl site) on the ribosome are attached to?
a tRNA's 3'-A end
Hemophilia in humans is due to a sex-linked recessive. What will be the results of mating between a normal (non-carrier) female and a hemophilac male?
all of the sons are normal and all of the daughters are carriers
Genes located on different chromosomes _____ sort independently
always
PCR (polymerase chain reaction)
amplifies DNA in vitro by incubating with special primers, DNA polymerase molecules, and nucleotides.
An RNA piece, copied from genomic DNA, that can reach the eucaryotic cytoplasm is known as a(an)?
an exon
Linked genes?
are carried on the same chromosome
Each polynucleotide strand in double stranded helical DNA?
are oriented in opposite directions (antiparallel)
RNA polymerase in transcription
attaches to the promoter region, uncoils DNA and makes mRNA until the terminator site is reached
Accuracy in the translation of mRNA into the primary structure of a polypeptide depends on specificity in the
bonding of the anticodon to the codon and the attachment of amino acids to tRNAs.
nonsense mutation
changes a normal codon into a stop codon
genes occur in
chromatin of nucleus (which condenses into chromosomes)
Mitosis: Prophase
chromosomes condense and appear, chromosomes form, nucleolus disappears, membrane breaks down, centrosomes start moving to the poles, spindle fibers and asters form
Prometaphase
chromosomes consisting of identical sister chromatids appear, the spindle microtubules attach to the kinetochores of the chromosomes.
elongation (translation)
codon recognition, peptide bond formation, translocation
Hershey-Chase Experiment
confirmed that DNA is the genetic material because only radiolabeled DNA could be found in bacteriophage-infected bacteria
lytic cycle
copies of a virus are made within a host cell, which then bursts open, releasing new viruses
Topisomerase
corrects "overwinding" ahead of replication forks by breaking, swiveling, and rejoining DNA strands
Vinblastine is a standard chemotherapeutic drug used to treat cancer, because it interferes with the assembly of microtubules, its effectiveness therefore would likely be related to?
disruption of the mitotic spindle
Genes located on the same chromosome _____ sort independently
do not
law of independent assortment
each pair of alleles segregates independently of other pairs of alleles during gametogenesis (except for linked genes)
A collection of DNA fragments made by treating DNA with restriction endonucleases that are then cloned in a bacterial plasmid or bacteriophage vector
gene library
point mutation
gene mutation in which a single base pair in DNA has been changed
cell cycle: G2 phase
growth and preparation for mitosis
protein molecules around which DNA is tightly coiled in chromatin. DNA packing
histones
a bacterial operon that is normally off and works by being turned on by a regulator molecule is
inducible operon
The role of a spliceosome role during transcription is to excise ____?_____ from a primary transcript
intron
What causes the decrease in the amount of cyclin at a specific point in the cell cycle?
its destruction by a process initiated by the activity of its complex with a cyclin
What causes the degradation in the amount of MPF-cyclin at the end of mitosis?
its destruction by a process initiated by the activity of the MPF (cdk-cyclin complex) itself
When does the synaptonemal complex disappear?
late prophase of meiosis I
the incorporation of a piece of viral DNA into a host cell's chromosome produces a
lysogenic phase of viral reproduction
initiation of translation
mRNA is attached to a subunit of the ribosome, the first codon is always AUG
One would expect to find a 5'-Cap and a 3' poly-A tail on which of the following molecules?
mRNA transported to the cytoplasm
Homologous pairs separate in
meiosis 1
Chromatids separate in
meiosis 2
If cells in the process of dividing are subjected to colchicine, a drug that interferes with the formation of the spindle apparatus, at which stage will mitosis be arrested?
metaphase
The type of point mutation where one nucleotide change results in a different amino acid being put into a polypeptide is known as?
missense mutation
Mitosis: Telophase
nuclear envelopes form around the identical sets of chromosomes at the 2 poles
Mitosis Interphase
nuclear membrane, nucleolus visible, chromatin not visible, two centrosomes present
translocation mutation
occur when a segment of DNA is swapped with a segment of DNA from another chromosome
termination of translation
occurs when a stop codon in the mRNA reaches the A site of the ribosome
progeny
offspring
very few genes have been located on the Y chromosomes of humans. Y-linked genes include a gene called testis-specific protein Y. A male with this gene will
pass the gene only to his sons
In sickle-cell disease, a change in one base pair results in one amino acid being substituted for another in the β-globin protein. This type of mutation is referred to as a _______ mutation.
point
Cell Cycle: G1
prepares for cell to duplicate and activates dna polymerase and activates genes in order for process to occur
In order for DNA polymerase III to begin copying DNA deoxynucleotides into a newly made complementarystrand it must add them to an existing short strand of nculeotides that is made by which of the following enzymes?
primase
When we see chiasmata under a microscope, that lets you know that which of the following stages of cell division is occurring?
prophase I of meiosis
exonuclease
removes RNA primers
DNA polymerase I
removes the RNA primer and replaces it with DNA nucleotides
Bacterial enzymes that cut DNA at unique sequences along DNA molecules are?
restriction endonucleases
To make a DNA gene probe that could be used to localize an active protein coding gene withinchromosomal DNA in eukaryotic cells one would best use which of the following to make the probe?
reverse transcriptase
Meiosis 1
separates homologous chromosomes and produces 2 haploid cells with sister chromatids still joined
fission (asexual reproduction)
separation of a parent into two or more individuals of about the same size
meiosis 2
sister chromatids separate and form 4 haploid cells
Mitosis: Anaphase
sister chromatids separate into individual chromosomes and are moved apart into two groups near the poles of the spindle Microtubules are attached to kinetochore and the chromatids are pulled apart
chiasma
site of crossing over for sister chromatids
which of the following occurs in meiosis but not mitosis
synapsis of chromosomes
The farther apart 2 genes are
the higher the probability that a crossover will occur between them
Mitosis: Metaphase
the mitotic spindle is fully formed and microtubules attached to kinetochores move the chromosomes to the metaphase plate
synapsis
the pairing of homologous chromosomes
what product molecule of transcriptions is cut up to produce mRNA
the primary transcript
In the Alfred Hershey & Martha Chase bacteriophage experiments they radioactively labeled the presumed genetic molecules of bacteriophage viruses using 32^P and 35^S. Which of the following cellular macromolecules was labeled with 35^S ?
the proteins
A promoter sequence in DNA, such as the TATA box (TATAAT), recognizes which of the following parts of an RNA polymerase enzyme?
the sigma factor
bacterial conjugation
the transfer of genetic material between bacterial cells by direct cell-to-cell contact
lysogenic cycle
the viral DNA is added to the host cell's DNA and is copied along with the host cell's DNA
Men with red-green color blindness inherited the gene for it from?
their mothers
a permanent, hereditable change in a cell that results from the uptake and incorporation of "foreign" DNA into the host cell's genome.
transformation
If one were to treat a sample of heat-killed Streptococcus pneumoniae S-straincells with ribonuclease enzymes?
transformation of R-strain cells with the heat-killed S-cells would be able to occur
MPF
triggers the cell to pass the G2 checkpoint and go onto mitosis switches on/off target cell cycle proteins by phosphorylating them
Split genes
use spliceosomes to excise introns and then join exons
Griffith's transformation experiment
used the heat-killed bacteria in mice to discover that a factor in heat-killed, disease-causing bacteria can "transform" harmless bacteria into ones that can cause disease
Budding (asexual)
when a new organism grows out of the parent's body of a parent. genetically identical
