All AP Biology Resources
Example Questions
Example Question #3 : Understand Steps Of Transcription
Which statement is true regarding DNA?
It is a protein
It is a single-stranded molecule
It contains adenine, guanine, cytosine, and uracil
It contains adenine, guanine, cytosine, and thymine
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 #2 : Understand Steps Of Transcription
What is the role of an activator?
Binds to RNA polymerase to initiate transcription
Activates transcription of the entire genome
Decreases transcription of a specific gene
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 #3 : Understand Steps Of Transcription
Where does RNA polymerase bind during transcription?
RNA polymerase binds to the sequence downstream of the promoter sequence.
RNA polymerase binds to the promoter sequence within the DNA template.
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 #17 : 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 #2291 : Ap Biology
What type of chromatin would be found in telomeres and centromeres?
Either heterochromatin or euchromatin, depending on the cell type
Heterochromatin
Euchromatin
Neither heterochromatin nor euchromatin
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 #2292 : Ap Biology
If a DNA template (the strand actively being transcribed) begins with AAGGCTCGGAA, what will the nascent RNA template begin with?
TTCCGAGCCTT
AAGGCTCGGAA
CCTTAGATTCC
AUGUGUTTCUG
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 #2293 : Ap Biology
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?
Myosin
Collagen
Histones
Actin
Polymerases
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.
Example Question #2294 : Ap Biology
In transcription, the promoter is __________.
a sequence of DNA that designates the starting point for RNA polymerase
a protein that increases the transcription levels for a given gene
a protein that guides RNA polymerase to the starting point
an RNA sequence that signals the start of translation
a sequence of DNA that designates the starting point for RNA polymerase
Transcription requires a DNA sequence that signals the RNA polymerase where to begin transcribing a given gene. The promoter is the DNA sequence that allows the RNA polymerase to bind to the right spot on the DNA and begin transcription. This prevents transcription of partial proteins or protein fragments that would be non-functional and possibly harmful to the cell.
Example Question #2295 : Ap Biology
Where does transcription take place in eukaryotic cells?
Ribosomes
The cytoplasm
The rough endoplasmic reticulum
The nucleus
The nucleus
Transcription is the process of synthesizing RNA from a DNA template. In eukaryotic cells, chromosomal DNA is contained within the nucleus. Transcription requires access to this DNA, and therefore must occur in the nucleus. Resulting RNA molecules are then shuttled out of the nucleus to be used in other processes.