Module 4
If an organism with the genotype AaBb produces gametes, what proportion of the gametes would be Bb?
None
The RNA segments joined to one another by spliceosomes are _____.
exons
Place the events in the transcription of a gene in their proper order
1.RNA polymerase binds promoter. 2.RNA polymerase transcribes gene. 3. RNA polymerase reaches terminator. 4. RNA polymerase exits gene, RNA is released.
Two organisms with genotype AaBbCcDdEE mate. These loci are all independent. What fraction of the offspring will have the same genotype as the parents?
1/16
_______of translation always happens at the start codon of the mRNA.
Initiation
AEDC-BFGH
Inversion
TI-JMLKN
Inversion
B
Which of these is a tRNA?
Translation occurs in the _____.
cytoplasm
After an RNA molecule is transcribed from a eukaryotic gene, what are removed and what are spliced together to produce an mRNA molecule with a continuous coding sequence?
introns ... exons
An _________________is the removal of a segment followed by its reinsertion into the same chromosome in the reverse orientation.
inversion
the promoter
n the diagram below, the green unit represents _____.
In gel electrophoresis DNA molecules migrate from _____ to _____ ends of the gel.
negative ... positive
A codon consists of _____ bases and specifies which _____ will be inserted into the polypeptide chain.
three ... amino acid
What name is given to the process in which a strand of DNA is used as a template for the manufacture of a strand of pre-mRNA?
transcription
The process, performed by the ribosome, of reading mRNA and synthesizing a protein is called _________________.
translation
What name is given to the process in which the information encoded in a strand of mRNA is used to construct a protein?
translation
A ________________ is the transfer of a segment to a nonhomologous chromosome. Translocations may be reciprocal (two nonhomologous chromosomes exchange segments) or nonreciprocal (one chromosome transfers a segment without receiving one).
translocation
AB-CLMN I-JKDEFGH
translocation
AB-CDDCEFGH
Duplication
During which step in the PCR cycle are nucleotides used?
Extension.
Two mice are heterozygous for albinism (Aa) . The dominant allele (A) codes for normal pigmentation, and the recessive allele (a) codes for no pigmentation. What percentage of their offspring would have an albino phenotype?
25
How many DNA molecules would there be after four rounds of PCR if the initial reaction mixture contained two molecules?
32
The direction of synthesis of an RNA transcript is _____.
5' —> 3'
What is the polymerase chain reaction (PCR)?
A method to amplify a fragment of DNA.
If a diploid cell undergoes meiosis and produces two gametes with n + 1 chromosomes and two gametes with n− 1 chromosomes, what type of error occurred?
A nondisjunction error occurred in meiosis I, in which both members of a homologous pair migrated to the same pole of the cell.
If a diploid cell undergoes meiosis and produces two gametes that are normal, and one with n − 1 chromosomes, and one with n + 1 chromosomes, what type of error occurred?
A nondisjunction error occurred in meiosis II, in which both sister chromatids of a chromosome migrated to the same pole of the cell.
Transcription begins at a promoter. What is a promoter?
A site in DNA that recruits the RNA Polymerase
What kind of cell results when a diploid and a haploid gamete fuse during fertilization?
A triploid cell
At which site do new aminoacyl tRNAs enter the ribosome during elongation?
A-site
What determines which base is to be added to an RNA strand during transcription?
Base pairing between the DNA template strand and the RNA nucleotides
What is the difference between heterozygous and homozygous individuals?
All of the gametes from a homozygote carry the same version of the gene while those of a heterozygote will differ.
What is a nondisjunction?
An error in cell division that causes homologous chromosomes or sister chromatids to move to the same side of the dividing cell
During which step in the PCR cycle do primers form bonds with a single-stranded template?
Annealing.
Which one restriction enzyme satisfies all three of the requirements listed above?
BamHI only
Which enzyme(s) would produce sticky ends when cutting both the human DNA and the plasmid?
BamHI, EcoRI, and HindIII,
Which enzyme(s) would cut the human DNA on both sides of the vgp gene, but not inside the gene?
BamHI, HaeIII, and HindIII
Which enzyme would cut the plasmid without disrupting the function of the amp gene?
BamHi, EcoRI, and HaeIII
How could the botanist best determine whether the genotype of the green-pod plant is homozygous or heterozygous?
Cross the green-pod plant with a yellow-pod plant.
The tRNA anticodon, GAC, is complementary to the mRNA codon with the sequence _____.
CUG
Which of the following terms best describes the relationship between the newly synthesized RNA molecule and the DNA template strand?
Complementary
True or false. A tRNA with an anticodon complementary to the stop codon catalyzes the reaction by which translation is terminated.
False
True or false? In diploid organisms, a dominant phenotype will only be expressed if the individual is homozygous dominant for that trait.
False
True or false? The Taq enzyme is a type of DNA polymerase that allows researchers to separate the DNA strands during the annealing step of the PCR cycle without destroying the polymerase.
False
Which of these correctly illustrates the pairing of DNA and RNA nucleotides?
GTTACG CAAUGC
Which enzyme(s) will produce a DNA fragment that contains the entire vgp gene (shown in red) and has "sticky ends"?
HindIII BamHI
When can nondisjunction occur? Choose the best answer.
In meiosis, when sister chromatids fail to separate All three answers are correct. In mitosis, when sister chromatids fail to separate In meiosis, when homologous chromosomes fail to separate
RNA polymerase
In the diagram below, the gray unit represents _____.
DNA
In the diagram below, the two blue strands represent _____.
What happens to RNA polymerase II after it has completed transcription of a gene?
It is free to bind to another promoter and begin transcription.
Which of the following is true about a plant with the genotype AABbcc?
It is homozygous at two loci.
Folk singer Woody Guthrie died of Huntington's disease, an autosomal dominant disorder. Which statement below must be true?
It is very likely that at least one of Woody Guthrie's parents also have had the allele for Huntington's disease.
What is the function of RNA polymerase?
It unwinds the double helix and adds nucleotides to a growing strand of RNA.
_________ of translation happens when the ribosome hits a stop codon on the mRNA.
Termination
DNA does not store the information to synthesize which of the following?
Organelles
In his breeding experiments, Mendel first crossed true-breeding plants to produce a second generation, which were then allowed to self-pollinate to generate the offspring. How do we name these three generations?
P ... F1 ... F2
Which of the following processes is an example of a post-translational modification?
Phosphorylation
What name is given to the process in which pre-mRNA is edited into mRNA?
RNA processing
You cross a true-breeding red-flowered snapdragon with a true-breeding white-flowered one. All of the F1 are pink. What does this say about the parental traits?
Red shows incomplete dominance over white.
Where does translation take place?
Ribosome
Which of the following is true of an X-linked gene, but not of a Y-linked gene?
The gene is present in both males and females.
Which of the following steps occurs last in the initiation phase of translation?
The large ribosomal subunit joins the complex.
In humans, what determines the sex of offspring and why?
The male gamete determines sex because each male gamete can contribute either an X or a Y chromosome.
Which of the following statements best describes the promoter of a protein-coding gene?
The promoter is a nontranscribed region of a gene.
What is meant by translocation?
The ribosome slides one codon down the mRNA.
-ACGT
The sticky end of the DNA restriction fragment shown here will pair with a DNA restriction fragment with the sticky end _____.
The role of RNA in the flow of genetic information
Trancsription/ RNA processing -mRNA Translation -rRNA -tRNA
What is the process called that converts the genetic information stored in DNA to an RNA copy?
Transcription
AB-CDEKLMNFGH I-J
Translocation
Of the following chromosomal abnormalities, which type is most likely to be viable in humans?
Trisomy
True or false? Comparison of the sequences of the same gene across species can give some insight into the existence of a common ancestor with that gene.
True
True or false? The same phenotype can be produced by more than one genotype.
True
Which syndrome is characterized by the XO chromosome abnormality?
Turner syndrome
Archaeologists unearthed a human skull with a small dried fragment of the scalp still attached. They extracted a tiny amount of DNA from the scalp tissue. How could they obtain sufficient DNA for an analysis of the ancient human's genes?
Use the polymerase chain reaction.
initiation (of translation)
What is the name of the process shown in the diagram?
What information can not be obtained from the sequence of a gene?
Whether the gene is methylated.
terminator promoter gene
Which of the following terms associated with transcription describe regions of nucleic acid?
E
Which of these DNA molecules is the shortest?
This means that the F1 generation makes gametes with the following genotypes
YR, Yr, yR, yr
The resulting offspring--the F1 generation--have genotype
YyRr
Height in humans generally shows a normal (bell-shaped) distribution. What type of inheritance most likely determines height?
a combination of polygenic inheritance and environmental factors
Generally speaking, which of the following mutations would most severely affect the protein coded for by a gene?
a frameshift deletion at the beginning of the gene
During RNA processing a(n) _____ is added to the 3' end of the RNA.
a long string of adenine nucleotides
In recombinant DNA experiments, what is used to cut pieces of DNA and what joins the resulting fragments to form recombinant DNA?
a restriction enzyme ... DNA ligase
According to Mendel's law of independent assortment, the alleles for seed color and seed shape are transmitted into gametes in
all possible combinations
Polypeptides are assembled from _____.
amino acids
Amino acids are attached to tRNA by enzymes called ___________.
aminoacyl-tRNA synthetase
What enzyme catalyzes the attachment of an amino acid to tRNA?
aminoacyl-tRNA synthetase
What is an allele?
an alternative version of a gene
What results if a fragment of a chromosome breaks off and then reattaches to the original chromosome at the same place but in the reverse direction?
an inversion
A _________ is the loss of part of a chromosomal segment.
deletion
AB-CDEFH
deletion
A ______________is the repetition of a segment. The repeated segment may be located next to the original or at a different location, and its orientation may be the same as the original or the reverse.
duplication
I-JNKLMN
duplication
Consider pea plants with the genotypes GgTt and ggtt . These plants can each produce how many type(s) of gametes?
four ... one
At fertilization, two gametes (egg and sperm) come together. The resulting F2 generation exhibits _________different phenotypes in the ratio of ------.
four... 9 to 3 to 3 to 1
Base substitution mutations and frameshift mutations If a segment of DNA were replicated without any errors, the replicated strand would have the following sequence of nucleotides: 5' - ACTACGTGA - 3' Sort the following replicated DNA sequences by the type of point mutation each contains (frameshift, base substitution, or neither), as compared to the correct sequence shown above.
frameshift mutation 5'-ACTTACGTGA-3' 5'-ACTCGTGA-3' base substitution mutation 5'-ACTAAGTGA-3' 5'-ACTACGTGT-3'
The flow of information in a cell proceeds in what sequence?
from DNA to RNA to protein
When constructing a Punnett square, the symbols on the outside of the boxes represent _______, while those inside the boxes represent _______.
gametes, progeny
Suppose that the botanist carried out the test cross described in Parts A and B and determined that the original green-pod plant was heterozygous (Gg). Which of Mendel's findings does her test cross illustrate?
law of segregation
Gel electrophoresis separates DNA fragments on the basis of what characteristic?
length
RNA processing converts the RNA transcript into _____.
mRNA
Which nucleic acid is translated to make a protein?
mRNA
DNA cloning is a technique for producing
many copies of a DNA segment for use in research, medicine, agriculture, or other applications.
During which part of meiosis (meiosis I or meiosis II) do the two alleles of a gene separate? During which phase does the separation occur?
meiosis I, anaphase
During RNA processing a(n) _____ is added to the 5' end of the RNA.
modified guanine nucleotide
The initiator tRNA attaches at the ribosome's _____ site.
p
Spliceosomes are composed of _____.
snRNPs and other proteins
The unpaired nucleotides produced by the action of restriction enzymes are referred to as _____.
sticky ends
The RNA that has an amino acid attached to it, and that binds to the codon on the mRNA, is called a ______.
tRNA
Properties of RNA Sort each description by the type of RNA it describes.
tRNA -contains an anticodon -has amino acids covalently attached mRNA -specifies the amino acid sequence for a protein -contains exons. rRNA -is a component of ribosomes -is the most abundant form of RNA
A tall, purple-flowered pea plant (TtPp) is allowed to self-pollinate. (The recessive alleles code for short plants and white flowers.) The phenotypic ratio of the resulting offspring is 9:3:3:1. What is the genotype of the plant whose phenotype appeared once out of every 16 offspring (the "1" in the 9:3:3:1 ratio)?
ttpp
In the P generation, a true-breeding pea plant with genotype YYRR is crossed with a true-breeding plant with genotype
yyrr