Cell Bio Exam 1
The classic beads on a string structure is the most decondensed chromatin structure possible and is produced experimentally. Which chromatin components are retained when this structure is generated? A - linker DNA B - nucleosome core particles C - core histones D - all of them
D
The first step in the formation of a transcription complex for mRNA transcription is the binding of __________ to the TATA box A - TFIA B - TFIIA C - TFIIIA D - TFIID
D
Which of the following chemical groups is not used to construct a DNA molecule? A - five-carbon sugar B - phosphate C - nitrogen-containing base D - six carbon sugar
D
Sometimes, chemical damage to DNA can occur just before DNA replication begins, not giving the repair system enough time to correct the error before the DNA is duplicated. This gives rise to mutation. If the cytosine in the sequence TCAT is deaminated and not repaired, which of the following is the point mutation you would observe after this segment has undergone two rounds of DNA repliation? A - TTAT B - TUAT C - TGAT D - TAAT
A
Polypeptides are synthesized from amino acid building blocks. The condensation reaction between the growing polypeptide chain and the next amino acid to be added involves the loss of ____________. A - water molecule B - an amino group C - a carbon atom D - a carboxylic acid group
A
Translation occurs in what part of the cell? A - cytoplasm B - nucleus C - mitochondria D - cell membrane
A
Which amino acid would you expect a tRNA with the anticodon 5-CUU-3' to carry? A - lysine B - glutamic acid C - serine D - phenylalanine
A
A major difference between eukaryotic and prokaryotic RNA polymerases is that eukaryotic polymerases A - use a set of transcription factors to bind to and initiate transcription B - use sigma factors to initiate transcription C - start from promoters D - start from origins of replication
A
After the first and before the second chemical step of RNA splicing, the intron of the pre-mRNA.... A - is still covalently connected to the 3' exon and has an internal branch in the shape of a lariat B - is still covalently connected to the 3' exon and is linear C - is still covalently connected to the 5' exon and is linear D - is still covalently connected to both of its flanking exons and is linear
A
You decide to use different bacterial strains (each having one protein of the replication machinery mutated) in order to examine the role of individual proteins int he normal process of DNA replication. What part of the DNA replication process would be most directly affected if a strain of bacteria lacking primase were used to make the cell extracts? A - initiation of DNA synthesis B - unwinding of DNA double helix C - leading strand elongation D - lagging strand completion
A
At physiological pH, what is the approximate net charge of a hexapeptide with the following amino acid sequence? Trp-Ser-Asp-Val-Ile-Glu-Arg-Ser A : -2 B: -1 C: 0 D: +1 E: +2
B
DNA polymerases are processive, which means that they remain tightly associated with the template strand while moving rapidly and adding nucleotides to the growing daughter strand. Which pieces of the replication machinery accounts for this characteristic? A - helicase B - sliding clamp C - single strand binding protien D - primase
B
How many replication forks are formed when an origin of replication is opened? A - 1 B - 2 C - 3 D - 4
B
The human genome is a diploid genome. However, when germ-line cells produce gametes, these specialized cells are haploid. What is the total number of chromosomes found in each of the gametes (egg or sperm) in your body? A - 22 B - 23 C - 44 D - 46
B
The information stored in the DNA sequences is used directly as a template to make __________. A - lipids B - RNA C - polypeptides D - carbohydrates
B
The piece of RNA below includes the region that codes for the binding site for the initiator tRNA needed in translation. 5-GUUUCCCGUAUAC AUG GCUGCCGGGGGC-3 Which amino acid will be on the tRNA that is the first to bind to the A site of the ribosome? A - methionine B - alanine C - cysteine D - valine
B
Which of the following choices best describes the role of the lysosome? A - transport of the material to the Golgi B - clean up, recycling, and disposal of macromolecules C - sorting of transport vesicles D - the storage of excess macromolecules
B
Which of the following is not a feature commonly observed in beta sheets? A - antiparallel regions B - coiled coil patterns C - extended polypeptide backbone D - parallel regions
B
Which of the following organelles has both an outer and an inner membrane? A - Endoplasmic reticulum B - mitochondrion C - Lysosome D - peroxisome
B
Nucleosome isconsisting of A - Histone 1 and Histone 2A B - Histone octamer, Histone 1 and DNA wrapped around those C - Histone octamer and DNA wrapped around it D - RNA and DNA
C
Sometimes, chemical damage to DNA can occur just before DNA replication begins, not giving the repair system enough time to correct the error before the DNA is duplicated. This gives rise to mutation. If the adenosine in the sequence TCAT is depurinated and not repaired, which of the following is the point mutation you would observe after this segment after this segment has undergone two rounds of DNA replication? A - TCAT B - TAT C - TCT D - TGTT
C
The sigma subunit of bacterial RNA polymerase A - contains the catalytic activity of the polymerase B - remains part of the polymerase throughout transcription C - recognizes promoter sites in the DNA D - recognizes transcription termination sites in the DNA
C
In a DNA double helix, _________________________. A - the two DNA strands are identical B - purines pair with purines C - thymine pairs with cytosine D - the two DNA strands run antiparallel
D
RNA polymerase differs from DNA polymerase in that it A - synthesizes new strands of RNA in a 3' to 5' direction B - is a monomeric protein C - can synthesize a complementary strand without the two strands of DNA being separated D - does not require a primer to initiate synthesis of RNA
D
What makes it possible for proteins to have alpha helices and beta sheets? A - specific amino acid sequences B - side chain interactions C - the hydrophobic core interactions D - hydrogen bonds along the protein backbone
D
telomeres serve as caps at the end of linear chromosomes. Which of the following is not true regarding the replication of telomeric sequences? A - the lagging-strand telomeres are not completely replicated by DNA polymerase B - telomeres are made of repeating sequences C - additional repeated sequences are added to the template strand D - the leading strand doubles back on itself to form a primer for the lagging strand
D