bio quiz chapter 11
Which of the following statements regarding DNA packing is false?
DNA packing tends to promote gene expression
The lac operon in E. coli
prevents lactose-utilizing enzymes from being expressed when lactose is absent from the environment
Animal development is directed by
cell-to-cell signaling and signal transduction pathways.
A signal outside a cell triggers changes in the transcription and translation inside the cell through the process of
signal transduction pathways.
Most differentiated cells retain
a complete set of their genes, and retain the ability to express those genes under certain circumstances.
miRNA can be used by
cells to prevent infections from double-stranded RNA viruses.
Proteins that bind to DNA and turn on operons by making it easier for RNA polymerase to bind to a promoter are called
A gene operon consists of
transcribed genes, an operator, and a promoter.
In female mammals, the inactive X chromosome in each cell
becomes a Barr body
Which of the following permits a single gene to code for more than one polypeptide?
alternative RNA splicing
The carcinogen known to cause the most cases of cancer is
RNA splicing involves the
removal of introns from the molecule
All of the following mechanisms are used to regulate protein production except
Silencers are sites in DNA that
bind repressor proteins to inhibit the start of transcription.
The basis of cellular differentiation is
selective gene expression.
The expression of the tryptophan operon is controlled by
a repressor that is active when it binds to tryptophan.
Which of the following statements about proto-oncogenes is false?
A mutation in a tumor-suppressor gene can stop cell division immediately.
A homeotic gene
serves as a master control gene that functions during embryonic development by controlling the developmental fate of groups of cells.
which of the following statements regarding RNA and proteins is false?
In eukaryotes, one gene controls the production of just one functioning protein.
The coding regions of a gene (the portions that are expressed as polypeptide sequences) are called
Both prokaryotic and eukaryotic cells use ________ to turn certain genes on or off.
Which of the following statements about fruit fly development is false?
The location of the head and tail ends of the egg is primarily determined by the location of sperm entry during fertilization
Which of the following processes occurs when a salamander regenerates a lost limb?
Certain cells in the limb dedifferentiate, divide, and then redifferentiate to form a new limb
the site on DNA to which activators bind
Which of the following statements regarding stem cells is false?
Adult, but not embryonic, stem cells can be grown in laboratory culture.