All AP Biology Resources
Example Questions
Example Question #2 : Understand Steps Of Transcription
The TATA box is bound by which of the following proteins?
DNA polymerase I
Transcription factors
DNA polymerase III
RNA polymerase I
RNA polymerase II
Transcription factors
Transcription factors bind to the TATA box (found only in eukaryotes and archaea). The TATA box is a promoter region of a gene on the DNA. If the transcription factor that binds it is an activator, then it will interact with RNA polymerase II to form a transcription initiation complex and begin transcription of mRNA. DNA polymerases I and III are involved in DNA replication, and do not interact with the TATA box. RNA polymerase I is responsible for transcribing rRNA genes in the nucleolus.
Example Question #3 : Understand Steps Of Transcription
Which of the following are purines?
Cytosine only
Adenine only
Cytosine and guanine
Adenine and guanine
Guanine only
Adenine and guanine
To help remember which bases are purines and which are pyrimidines, there are two acronyms. Pure As Gold. Adenine and guanine are purines because of their structure. Also, pyrimidines, like pyramids, are "sharp". Sharp things CUT (cytosine, uracil and thymine).
Example Question #2291 : Ap Biology
Which statement is true regarding DNA?
It is a single-stranded molecule
It contains adenine, guanine, cytosine, and thymine
It is a protein
It contains adenine, guanine, cytosine, and uracil
It cannot be replicated
It contains adenine, guanine, cytosine, and thymine
DNA is a nucleic acid, made up of the nucleotides, which contain a deoxyribose sugar, a phosphate group, and one of four nitrogenous bases. These bases are adenine, cytosine, guanine, and thymine. DNA is double-stranded, but transiently single-stranded during DNA replication and transcription.
Example Question #2292 : Ap Biology
What is the role of an activator?
Binds to RNA polymerase to initiate transcription
Decreases transcription of a specific gene
Activates transcription of the entire genome
Increases transcription of a specific gene
Increases transcription of a specific gene
Activators are proteins that increase transcription of a specific gene. Activators bind to promoters and often coactivators to facilitate binding of the pre-activation complex and initiation complexes; therefore, they stimulate the transcription of a given gene.
Example Question #2293 : Ap Biology
Where does RNA polymerase bind during transcription?
RNA polymerase binds to the promoter sequence within the DNA template.
RNA polymerase binds to the sequence downstream of the promoter sequence.
RNA polymerase binds to the activators.
RNA polymerase binds to the transcription factors.
RNA polymerase binds to the promoter sequence within the DNA template.
During transcription, RNA polymerase enzymes bind to DNA promoter sequences. This binding is facilitated by the pre-initiation complex (composed of transcription factors, the promoter sequence, activators, and repressors) as well as RNA polymerase. In eukaryotic cells, certain transcription factors must bind to the promoter sequence before RNA polymerase can. This is due to an inability of RNA polymerase to independently recognize the promoter sequence. Once RNA polymerase does bind, transcription can be initiated.
Example Question #16 : Central Dogma
Which of the following proteins play a role in proofreading during transcription?
Activators
RNA polymerase
RNA ligase
Transcription factors
RNA polymerase
Proofreading occurs during the elongation phase of transcription. RNA polymerase's movement over the DNA template strand includes a backtracking motion that allows RNA polymerase to proofread the newly synthesized RNA transcript.
Example Question #11 : Central Dogma
Which of the following is the central dogma of biology?
The genetic information in a cell is stored in its DNA. Through transcription, the cell is able to create RNA from DNA. This RNA is called mRNA. The mRNA is then able to create protein through translation. Thus, the flow of information is from DNA to RNA to protein.
Example Question #11 : Understand Steps Of Transcription
What type of chromatin would be found in telomeres and centromeres?
Euchromatin
Heterochromatin
Neither heterochromatin nor euchromatin
Either heterochromatin or euchromatin, depending on the cell type
Both heterochromatin and euchromatin
Heterochromatin
Telomeres and centromeres are composed of heterochromatin. In contrast to euchromatin, heterochromatin's genes are generally in an inactive state. This is because the genetic material is highly condensed. Often, heterochromatin is thought of as "junk DNA". Since telomeres are slowly being degraded during DNA replication, the cell does not want to have active or important genes in this area. Same goes for centromeres, where there is the possibility of chromatids not separating evenly across the centromere in anaphase.
Example Question #12 : Understand Steps Of Transcription
If a DNA template (the strand actively being transcribed) begins with AAGGCTCGGAA, what will the nascent RNA template begin with?
AUGUGUTTCUG
TTCCGAGCCTT
CCTTAGATTCC
AAGGCTCGGAA
UUCCGAGCCUU
UUCCGAGCCUU
Simply create a complementary strand of RNA with matching base pairs, but substitute uracil (U) for thymine (T), since RNA does not use thymine base pairs.
The answer choice starting with AUG might seem appropriate since it is the start codon, however, realize that the rest of the base pairs do not match up to the DNA template. Further, RNA templates do not begin right at the start codon; there are promotoer and enhancer regions of DNA that are transcribed well before the first exon is transcribed with its AUG start codon.
Example Question #13 : Understand Steps Of Transcription
Eukaryotic DNA is packed in a chromatin structure, making it hard for DNA to be transcribed. What proteins are associated with the packing of DNA?
Polymerases
Histones
Myosin
Collagen
Actin
Histones
Histones are associated with DNA packed in chromatin. Acetylation of these histones allows for DNA transcription. Other proteins mentioned play no part in DNA chromatin structure.
Polymerases are active during DNA repair and transcription. Collagen is a fibrous protein associated with the extracellular matrix. Actin and myosin are myofilaments active in muscle contraction.
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