DNA Biology and Technology - Chapter 22 Flashcards
Mitochondria also contain DNA.
True
False
True
*Mitochondria contain a small, circular chromosome of DNA.
Which of the following are found within the monomer unit of DNA?
Amino acids, nitrogen bases
Phosphates, nitrogen bases
Fatty acids, sugars
Nitrogen bases, fatty acids
Phosphate, amino acids
Phosphate, nitrogen bases
*Phosphates and nitrogen bases, along with sugars, are found in the monomer unit of DNA.
Which of the following is a monomer unit of DNA?
Amino acids
Nucleotides
Carbohydrate rings
Steroid rings
Fatty acids
Nucleotides
*Nucleotides are the monomer unit of DNA
The bases in DNA are complementary. A always binds with
U.
G.
A.
T.
C.
T.
*A always binds with T. C always binds with G. U is found in the RNA strand, not DNA.
Which of the following is true about the structure of DNA?
A always pairs with T and G always pairs with C.
The bases form the “rungs” of the ladder structure.
The ladder structure is twisted into a double helix.
The sides of the ladder structure are made up of sugar and phosphate.
All of the answer choices are true of DNA structure.
All of the answer choices are true of DNA structure.
*All of the answer choices are true of DNA structure.
DNA replication is considered
Conservative
Relaxed
Semiconservative
Stringent
Dispersive
Semiconservative
*DNA replication is considered semiconservative because each DNA molecule is composed of one old strand and one new strand.
What is the role of the enzyme ligase in DNA replication?
It unzips the double-stranded DNA.
It breaks the hydrogen bonds that hold the two strands of the DNA together.
It seals any breaks in the sugar-phosphate backbone.
It matches new bases to the old strands by complementary base pairings.
It folds the DNA into a coiled structure.
It seals any breaks in the sugar-phosphate backbone.
*To complete reploication, the enzyme ligase seals any breaks in the sugar-phosphate backbone.
[_____________] are DNA building blocks that consist of a sugar, a phosphate, and a nitrogen base.
Nucleotides
Helicase
Polymerase
Nucleotides
An enzyme called DNA [____________] unzips, unwinds and separates the strands.
Nucleotides
Helicase
Polymerase
Helicase
An enzyme called DNA [_______________] adds new nucleotides to the growing daughter DNA strand.
Nucleotides
Helicase
Polymerase
Polymerase
The denaturation of which enzyme would most directly interrupt the process of the base pairing of nucleotides during DNA replication?
DNA polymerase
Binding proteins
DNA helicase
DNA ligase
Okazaki fragments
DNA polymerase
*DNA polymerase is the enzyme responsible for attaching the new complementary base pairs to the exposed strands. If this enzyme were denatured, bases would not be attached. DNA ligase is responsible for sealing any breaks in the sugar-phosphate backbone of the strand. DNA helicase unwinds the strand. Binding proteins help keep the unwound strand open during replication. Okazaki fragments are the short sections of replicated DNA that form from the lagging strand.
The sugar in DNA is deoxyribose while the sugar in RNA is ribose.
True
False
True
*DNA stands for deoxyribonucleic acid and RNA stands for ribonucleic acid.
In what way are DNA and RNA similar?
Both form a double helix.
Both contain U, C, and G.
Both contain deoxyribose.
Both are single-stranded.
Both contain C, A, and G.
Both contain C, A, and G.
* Both DNA and RNA contain C, A, and G.
Which of the following is a coding RNA?
Large RNA
mRNA
tRNA
Small RNA
rRNA
mRNA
*The coding RNA is messinger RNA (mRNA), which is translated into protein.
The “r” in “rRNA” stands for reticulum RNA because this type of RNA is associated with the endoplasmic reticulum.
True
False
False
*The “r” stands for ribosomal because this type of RNA is associated wiht ribosomes.
Which of the following is a type of small RNA?
siRNAs
snoRNAs
miRNAs
snRNAs
All of the answer choices are types of small RNA.
All of the answer choices are types of small RNA.
*All of the answer choices are types of small RNA.
How many different amino acids are found in proteins?
50
10
5
Over 100
20
20
*There are 20 different amino acids found in proteins.
The three-base sequence in a mRNA molecule is called a(n)
Codon.
Mutation.
Initiator.
Anticodon.
Transposon.
Codon
*The three-base sequence in the mRNA molecule is called a codon.
To transcribe something is to make an identical copy (i.e., if the original is DNA, the transcribed copy is also DNA).
True
False
False
*To replicate something is to make an identical copy. To transcribe is to make a faithful copy, but it is not identical. DNA is transcribed into RNA.
What enzyme is responsible for transcription (formation of mRNA)?
Ligase
DNA polymerase
Helicase
RNA polymerase
Protease
RNA polymerase
*RNA polymerase transcribes DNA into RNA.
Exons in mRNAs are excised and left in the nucleus.
True
False
False
*Exon is short for “expressed sequences.” Exons in mRNAs are spliced back together again after introns that are removed.
As the RNA is being made, it is exported from the nucleus to the cytoplasm for translation.
True
False
False
*The RNA must first be processed before it can leave the nucleus for the cytoplasm.
Which of the following is true regarding ribosomes?
They contain an A site and a P site.
They are composed of two subunits.
They translate RNA to protein.
They contain both RNA and protein.
All of the answer choices are true regarding ribosomes.
All of the answer choices are true regarding ribosomes.
*All of the answer choices are true regarding ribosomes.
Which structure contains the anticodon?
The small ribosomal subunit
The rRNA
The tRNA
The mRNA
The large ribosomal subunit
The tRNA
*The tRNA contains the anticodon that pairs with the codon.
If the codon is CCA, what is the anticodon, and what amino acid will be inserted?
CCA, proline
UGG, tryptophan
GGT, glycine
GGU, proline
ACC, threonine
GGU, proline
*If the codon is CCA, the anticodon is GGU, and the amino acid will be proline.
Which of the following occurs during the initiation of translation?
The ribosome moves down one codon so that the A site is available to receive an incoming tRNA.
One of the three stop codons is reached.
The mRNA binds to the smaller of the two ribosomal subunits.
The polypeptide lengthens one amino acid at a time.
The ribosome dissociates into its two subunits and falls off the mRNA.
The mRNA binds to the smaller of the two ribosomal subunits.
*The first step in initiation of translation is that the mRNA binds to the smaller of the two ribosomal subunits.
How many stop codons are there in the genetic code?
One
Two
Three
Four
Five
Three
*There are three stop codons in the genetic code: UAA, UAG, and UGA.
Which of the following would be an example of pretranscriptional control?
The life expectancy of the mRNA molecules vary.
The mRNA is degraded before translation can occur.
The chromosomes must decondense.
The polypeptide product is folded to form its functional conformation.
The mRNA is processed before it leaves the nucleus.
The chromosomes must decondense.
*Pretranscriptional control are things that occur before transcription begins. The uncoiling or decondensing of the chromosomes is one type of pretranscriptional control.
Which of the following is true about transcription factors?
There are many different types of transcription factors.
Transcription factors are DNA-binding proteins.
Genes code for transcription factors.
The specialization of cells is determined/influenced by which transcription factors are active in the cell.
All of the answer choices are true about transcription factors.
All of the answer choices are true about transcription factors.
*All of the answer choices are true about transcription factors.
An individual has a genetic disorder in which their cell is not forming the correct protein structure for the cell membrane to allow entry of a particular ion. Doctors have determined that in order to help cure this person, they need to alter the shape of the protein. Which type of regulation of gene expression would have the greatest chance of success?
Transcriptional control
Posttranslational control
Translational control
Posttranscriptional control
Pretranscriptional control
Posttranslational control
*Posttranslational control occurs after protein synthesis. The polypeptide can have its shape altered in order to make it biologically functional. Posttranscriptional control impacts the mRNA which can influence how fast mature mRNA leaves the nucleus, which can affect the amount of gene expression. Transcriptional control regulates which genes are transcribed, and the rate at which transcription of genes occurs. Altering this factor won’t correct the incorrect shape of the protein. Translational control determines whether or not the protein is formed, not the actual shape of the protein. Pretranscriptional control determines if the process of gene expression occurs or not.
When the sequence CGCAAUGCAAGGA is translated, the corresponding protein will be arginine-asparagine-alanine.
True
False
False
*Initiation must begin at AUG so the sequence would be methionine-glutamine-glycine,
Which of the following is an amino acid?
All of the answer choices are amino acids.
Alanine
Tryptophan
Valine
Glycine
All of the answer choices are amino acids.
*All of the answer choices are amino acids.
What is the name of the enzyme that fits new complementary DNA nucleotides into the new strand?
DNA helicase
DNA ligase
DNA telomerase
DNA polymerase
DNA replicase
DNA polymerase
*DNA polymerase is responsible for positioning and joining complementary base pairs during the process of DNA replication.
In the RNA sequence CAAUGACCAG, what will be the first amino acid incorporated?
Glutamine
Methionine
Valine
Alanine
Glycine
Methionine
*The ribosome will ignore the first CA nucleotides until it reaches the start codon (AUG). AUG codes for the amino acid methionine.
