Chapter 18 DSM
Chemotherapeutic treatment for breast cancer depends on the absence or overexpression of the __________ gene(s).
ERa, PR, and HER2 Treatment depends on the absence or excessive expression of the following receptors: estrogen receptor a (ERa), progesterone receptor (PR), and HER2.
Which of the following best describes the makeup of the human genome?
Genes for noncoding RNA make up the majority of meaningful genetic information in the human genome.
What gene has been called the "guardian angel of the genome?"
The p53 gene
What is the role of proteasomes?
They are giant protein complexes that recognize ubiquitin and degrade the tagged proteins.
In the lac operon, the inducer is __________.
allolactose, the isomer of lactose
Although the number of genes in the human genome is surprisingly low compared to less complex organisms, the number of possible products from those genes is greatly amplified by _________
alternate arrangements of exons from a primary transcript
Post-transcriptional processing of a pre-mRNA allows for differential cell expression by a process called __________.
alternative splicing
In prokaryotic genomes, groups of functionally related genes along with their promoters and operators are found together in __________.
an operon
The trp (tryptophan) operon is an example of a(n) __________ that is controlled by __________.
anabolic pathway; feedback inhibition
Cytoplasmic determinants __________.
are RNAs, proteins, and other substances produced by the mother and deposited in the egg Maternal substances in the egg that influence the course of early development are called cytoplasmic determinants.
Cell type-specific transcription is accomplished __________.
by specific enhancer control elements interacting with cell type-specific transcription factors
Gene expression in bacteria is regulated primarily by __________.
controlling the transcription of genes into mRNA
In Drosophila development, the anterior-posterior axis of the embryo is determined by __________.
egg-polarity genes
In a eukaryote, activating transcription factors may stimulate gene expression by binding to a DNA site called a(n) __________.
enhancer
In Drosophila development, pattern development in the late embryo, larva, and adult is controlled by __________.
homeotic genes
The control of gene expression is more complex in multicellular eukaryotes than in prokaryotes because __________.
in a multicellular eukaryote, different cells are specialized for different functions
Small noncoding RNAs (ncRNAs) called piwi-interacting RNAs, or piRNAs, __________.
induce the formation of heterochromatin and block the expression of movable DNA elements called transposons
The lac operon is an example of a(n) __________ operon.
inducible An inducible operon is usually off but can be stimulated (induced) when a specific small molecule interacts with a regulatory protein. The classic example of an inducible operon is the lac operon (lac for "lactose").
Specific cells that appear undifferentiated under the microscope but are already fated to become muscle cells are called __________.
myoblasts
In eukaryotes, histone acetylation __________.
promotes transcription Generally, histone acetylation appears to promote transcription by opening up the chromatin structure, whereas the addition of methyl groups can lead to the condensation of chromatin and reduced transcription.
In addition to a promoter, eukaryotic genes have control elements called __________.
proximal control elements and distal enhancers
What two genes are often mutated in colon cancer?
ras and p53
The trp (tryptophan) operon is an example of a(n) __________ operon.
repressible The trp operon is said to be a repressible operon because its transcription is usually on but can be inhibited (repressed) when a specific small molecule (in this case, tryptophan) binds allosterically to a regulatory protein
In the trp (tryptophan) operon, the __________ binds to the product of the trp operon synthesis pathway, called __________, forming the __________.
repressor protein; tryptophan; active repressor
MicroRNAs binding to complementary sequences on an mRNA __________.
results in either blocking translation or degrading the targeted mRNA
In an inducible operon, the inducer is often the __________ in the pathway being regulated; the inducer binds to the __________, thus rendering it __________.
substrate; repressor; inactive
Both repressible and inducible operons control gene expression at the level of __________.
transcription
MyoD promotes muscle cell development by __________.
turning on the expression of multiple muscle-related genes
