BIO 4
A particular triplet of bases in the template strand of DNA is 5' AGT 3'. The corresponding codon for the mRNA transcribed is
3' UCA 5'.
RNA polymerase moves in which direction along the DNA?
3' to 5' along the template strand
Which of the following does not occur in prokaryotic gene expression, but does occur in eukaryotic gene expression?
A poly-A tail is added to the 3' end of an mRNA and a cap is added to the 5' end.
Early in development, the fate of a cell is determined by ______________ deposited by the mother in the egg, but later in development it is influence by the cell's location and is influenced by positional information communicated by _______________.
Both B and D are correct.
Reproductive cloning of human embryos is generally considered unethical. However, on the subject of therapeutic cloning there is a wider divergence of opinion. Which of the following is a likely explanation?
Cloning to produce embryonic stem cells may lead to great medical benefits for many.
Gene expression might be altered at the level of post-transcriptional processing in eukaryotes rather than prokaryotes because of which of the following?
Eukaryotic exons may be spliced in alternative patterns.
Which of the following best describes the significance of the TATA box in eukaryotic promoters?
It is the recognition site for a specific transcription factor.
It has been possible to regenerate sheep and other mammals using the nucleus/genome of a differentiated cell, but which of the following has been an essential part of the experimental approach?
The nucleus must be transferred to the cytoplasm of an egg or pleuripotent cell.
In animals, what is the difference between reproductive cloning and therapeutic cloning?
Therapeutic cloning supplies cells for repair of diseased or injured organs.
Which of the following statements describes proto-oncogenes?
They can code for proteins associated with cell growth.
A particular triplet of bases in the coding sequence of DNA is AAA. The anticodon on the tRNA that binds the mRNA codon is
UUU.
If a Drosophila female has a homozygous mutation for a maternal effect gene,
all of her offspring will show the mutant phenotype, regardless of their genotype.
Altering patterns of gene expression in prokaryotes would most likely serve the organism's survival in which of the following ways?
allowing the organism to adjust to changes in environmental conditions
Tumor-suppressor genes
can encode proteins that promote DNA repair or cell-cell adhesion.
A mutation that inactivates the regulatory gene of a repressible operon in an E. coli cell would result in
continuous transcription of the structural gene controlled by that regulator.
Muscle cells differ from nerve cells mainly because they
express different genes.
In 1997, Dolly the sheep was cloned. Which of the following processes was used?
fusion of an adult cell's nucleus with an enucleated sheep egg, followed by incubation in a surrogate
In colorectal cancer, several genes must be mutated in order to contribute to a cell developing into a cancer cell, supporting Knudsen's hypothesis. Which of the following kinds of genes would you expect to be mutated?
genes involved in control of the cell cycle
Forms of the Ras protein found in tumors usually cause which of the following?
growth factor signaling to be hyperactive
Mutations in which of the following genes lead to transformations in the identity of entire body parts?
homeotic genes
Suppose you found a Drosophila mutant that has legs coming out of the head instead of antennae. A mutation that caused this phenotype is likely to be found in ________.
homeotic genes
Which of the following, when taken up by the cell, binds to the repressor so that the repressor no longer binds to the operator?
inducer
Absence of bicoid mRNA from a Drosophila egg leads to the absence of anterior larval body parts and mirror-image duplication of posterior parts. This is evidence that the product of the bicoid gene
normally leads to formation of head structures.
Transcription factors in eukaryotes usually have DNA binding domains as well as other domains that are also specific for binding. In general,
other transcription factors
Embryonic lethal mutations result in
phenotypes that are never born/hatched.
The process of translation, whether in prokaryotes or eukaryotes, requires tRNAs, amino acids, ribosomal subunits, and which of the following?
polypeptide factors plus GTP
Which of the following experimental procedures is most likely to hasten mRNA degradation in a eukaryotic cell?
removal of the 5ʹ cap
Transcription in eukaryotes requires which of the following in addition to RNA polymerase?
several transcription factors
The product of the bicoid gene in Drosophila provides essential information about
the anterior-posterior axis.
The lactose operon is likely to be transcribed when
the cyclic AMP and lactose levels are both high within the cell.
Which of the following is the first event to take place in translation in eukaryotes?
the small subunit of the ribosome recognizes and attaches to the 5' cap of mRNA
The fact that different kinds of cells in an individual have the same genes, and therefore any cell should have the potential to generate a genetically identical, complete new organism (clone) refers to which of the following concepts?
totipotency
The tryptophan operon is a repressible operon that is
turned off whenever tryptophan is added to the growth medium.
The genetic code is essentially the same for all organisms. From this, one can logically assume which of the following?
A gene from an organism can theoretically be expressed by any other organism.
The bicoid gene product is normally localized to the anterior end of the embryo. If large amounts of the product were injected into the posterior end as well, which of the following would occur?
Anterior structures would form in both sides of the embryo.
A transcription unit that is 8,000 nucleotides long may use 1,200 nucleotides to make a protein consisting of approximately 400 amino acids.
It is the recognition site for a specific transcription factor.
The phenomenon in which RNA molecules in a cell are destroyed if they have a sequence complementary to an introduced double-stranded RNA i
RNA interference.
In eukaryotes there are several different types of RNA polymerase. Which type is involved in transcription of mRNA for a globin protein?
RNA polymerase II
The first cloned cat, called Carbon Copy, was a calico, but she looked significantly different from her female parent. Why?
X inactivation in the embryo is random and produces different patterns.
In eukaryotes, general transcription factors
bind to other proteins or to a sequence element within the promoter called the TATA box.
The role of a metabolite that controls a repressible operon is to
bind to the repressor protein and activate it.
Which of the following is the correct order of transcription factor activity during development of the drosophila embryo?
maternal effect genes; gap genes; homeotic genes
Transcription factors in eukaryotes usually have DNA binding domains as well as other domains that are also specific for binding. In general, which of the following would you expect many of them to be able to bind?
other transcription factors
What is considered to be the first evidence of differentiation in the cells of an embryo?
the occurrence of mRNAs for the production of tissue-specific proteins
Cell differentiation always involves
the production of tissue-specific proteins, such as muscle actin.