Chapter 11: DNA BiologyAssignment
Choose three (3) correct statements about the promoter region.
- It is where RNA polymerase binds on DNA. - It is located on the DNA strand. - It marks the beginning of a new gene.
In the lac operon, when lactose is present, which of the following are true?
- RNA polymerase binds to the promoter on the lac operon. - Lactose binds to the repressor and changes its shape.
Select the double-ringed purines.
- adenine - guanine
Select all of the following which take place during gene expression.
- binding of tRNAs to their specific amino acids - the joining of the small and large subunits of the ribosome - transcription of the DNA into an mRNA template - binding of codons to anticodons
Which of the following are possible with additional nucleotides in the genetic code?
- food with higher nutritional content - pathogen resistant organisms - far greater potential amino acids - new drugs and vaccines
Alternative mRNA processing involves which two of the following?
- removal of introns - splicing together of exons
Choose the two steps involved in gene expression from the choices below.
- translation - transcription
Events are in order by which they occur during gene expression.
1. the mRNA transcript is produced in the nucleus 2. the mRNA transcript binds to the ribosome 3. the tRNA anticodon binds its complementary codon bringing its specific its amino acids to the ribosome. 4. a polypeptide is synthesized as the mRNA is read and more amino acids are brought by the tRNAs 5. at termination, the ribosomal subunits and the mRNA dissociate
The traditional nucleotides, A, C, T and G, code for
20 amino acids.
What is a dark-staining portion of female, mammal DNA containing an inactive X chromosome called?
Barr body
transcription
DNA is used as a template to produce RNA.
replication
DNA is used as a template to produce duplicate molecules of DNA.
Which choice identifies the flow of information according to the central dogma of molecular biology?
DNA to RNA to protein
Which of the following is true about gene expression in different cells?
Each cell has the full complement of genes but only certain ones are expressed.
True or false: All somatic cells in the human body contain the same combinations of proteins.
False; All cells have the same chromosomes, but each cell type contains its own mix of proteins that makes it different from other cell types.
True or false: When chromatin is condensed, transcription is active.
False; Chromatin must be decondensed in order for transcriptional factors to have access to the template strand.
Where does protein synthesis occur?
In the cytoplasm
When lactose is present, what happens to the repressor?
It becomes inactive.
translation
RNA is used to produce protein.
During transcription, the enzyme complex known as __________ creates an RNA molecule by joining nucleotides complementary to a DNA template.
RNA polymerase
During transcription, what is the name of the enzyme complex responsible for opening up the DNA strand so base pairing can occur?
RNA polymerase
Which of the following is NOT a level of eukaryotic gene expression control?
Replicational control
DNA replication occurs during the ___________ phase of the cell cycle.
S
Use the genetic code to answer this question. The amino acid specified by the codon ACC is
Thr or threonine
When a repressor protein binds to the operator of a gene, what is the effect on transcription of that gene?
Transcription does not occur.
Which one of the following is the protein required for the initiation of transcription by RNA polymerase in eukaryotes?
Transcription factor
True or false: A newly translated eukaryotic polypeptide often must go through modification before becoming an active gene product.
True
True or false: The products of DNA transcription of a gene for a protein are known as mRNA transcripts.
True; : mRNA transcripts are produced during the transcription of DNA.
If a template strand of DNA has the base sequence order AATGCC, which of the following is the base sequence order for the resulting mRNA transcript?
UUACGG
Barr bodies are found in the ______ chromosome.
X
Identify the new nucleotides that have been created by scientists.
Y; X
The product of the transcription of a strand of DNA is
a complementary strand of RNA (transcription produces all 3 types of RNA; mRNA, rRNA, & tRNA)
Chromatin structure helps control gene expression by
allowing transcription when it is decondensed.
During the process of translation, a codon matches up with its complement, a(n)
anticodon
The three-base sequence in a tRNA molecule that pairs with a complementary codon on mRNA is known as a(n) _____.
anticodon
codon
binds to the ribosome and to the anticodon
amino acid
brought to the ribosome by tRNA
A three-nucleotide unit on a strand of mRNA that codes for a specific amino acid is called a
codon
Match the terms on the left with their best match on the right.
codon- mRNA anticodon- tRNA protein- amino acid
UUU and UUG are both examples of _____ that correspond to the amino acid phenylalanine in the genetic code.
codons
The mRNA transcript produced during transcription is _____ to the original strand of DNA.
complementary
Female mammals have a(n) ______ amount of protein product from genes located on the X chromosomes compared to the amount of gene product from genes on autosomes.
decreased
Changes in gene regulation at the cellular level which are inherited from one generation to the next is known as __________ inheritance.
epigenetic
X-inactivation, which can be physically observed in the coloring of calico cats, is an example of _________ inheritance, which does not result from changes in the sequence of nucleotides on the chromosome.
epigenetic
When condensed chromatin is unpacked and accessible for transcription, it is called _____.
euchromatin
Most of the time, DNA is only loosely coiled, a form called __________ , which allows genes to be active.
euchromatin or chromatin
Segments of mRNA that contain the protein-coding portion of a gene, which are joined together during splicing, are called _____.
exons
The coding portions of a gene that are joined during mRNA processing are called
exons
The portion of the chromatin that is inactive is called _______.
heterochromatin
Heterochromatin is a portion of the chromatin that is
inactive
During RNA process which structures are removed from the strand?
introns
Most genes in humans are interrupted by segments of DNA that do not code for a protein. These segments, which are removed from mRNA during mRNA processing, are called
introns
What are the segments of noncoding human DNA, which are removed from mRNA during mRNA processing, called?
introns
In alternative mRNA processing, eukaryotic gene expression is controlled when __________ are removed from the original transcript and the remaining __________ are spliced together before the final transcript exits the nucleus.
introns; exons
This diagram depicts the alteration of an insulin molecule, a polypeptide, from its form immediately after synthesis to its active structure. This alteration of insulin
is a means of controlling the expression of the gene coding for insulin.
During gene expression, transcription takes place in the _____ of the cell while translation takes place in the _____.
nucleus; cytoplasm
First described by Jacob and Monod, a(n) __________ is a group of genes and the DNA sequences that control their transcription.
operon
A group of genes and the DNA sequences that control their transcription are known as _______.
operons
Which of the following are found in all DNA nucleotides?
phosphate; nitrogen-containing base
anticodon
portion of the tRNA undergoing complementary binding with the codon
During mRNA __________ , a cap and poly-A tail are added, introns are removed, and the exons are then joined together.
processing
In prokaryotes, RNA polymerase binds to a short sequence of DNA called the _____.
promoter
The process by which new DNA nucleotides are added to the existing DNA chain using the enzyme DNA polymerase is called DNA
replication
A protein that binds to the operator, thus shutting down transcription of the gene, is termed a(n)
repressor
The site of protein synthesis in the cytoplasm is the
ribosome or polyribosome
During translation, which structure will carry the amino acids to the ribosome?
tRNA
In cats, the alleles for black or orange coat color are carried on the X chromosome. In female cats heterozygous for black/orange coat color, the coat color is patchy, showing black patches in some places and orange patches in others. What is the best explanation for this coloring?
the random inactivation of one of the two X chromosomes in all cells
DNA-binding proteins that help RNA polymerase bind to a promoter in eukaryotic cells are called
transcription factors
Polypeptides are created during which process?
translation
The process of ___________ uses mRNA, tRNA, and ribosomes to synthesize proteins.
translation