Bio Exam 4: Chapter 18

Which of the following types of mutation would convert a proto-oncogene into an oncogene? a) a mutation that blocks transcription of the proto-oncogene b) a mutation that creates an unstable proto-oncogene mRNA c) a mutation that greatly increases the amount of the proto-oncogene protein d) a deletion of most of the proto-oncogene coding sequence

The product of the p53 gene _____. a) causes cells to reduce expression of genes involved in DNA repair b) slows down the rate of DNA replication by interfering with the binding of DNA polymerase c) allows cells to pass on mutations due to DNA damage d) inhibits the cell cycle

Tumor-suppressor genes _____. a) encode proteins that help prevent uncontrolled cell growth b) are cancer-causing genes introduced into cells by viruses c) are frequently overexpressed in cancerous cells d) often encode proteins that stimulate the cell cycle

In colorectal cancer, several genes must be mutated for a cell to develop into a cancer cell. Which of the following kinds of genes would you expect to be mutated? a) genes that are especially susceptible to mutation b) genes involved in control of the cell cycle c) genes of the bacteria, which are abundant in the colon d) genes coding for enzymes that act in the colon

Which of the following would be most likely to lead to cancer? a) failure of a proto-oncogene to produce a protein and amplification of a tumor-suppressor gene b) hyperactivity of a proto-oncogene and activation of a tumor-suppressor gene c) failure of both a proto-oncogene and a tumor-suppressor gene to produce proteins d) hyperactivity of both a proto-oncogene and a tumor-suppressor gene e) amplification of a proto-oncogene and inactivation of a tumor-suppressor gene

Segment of DNA positioned within the promoter that serves as an "on-off switch" and controls the access of RNA polymerase to the genes

The entire stretch of DNA including the operator, the promoter, and the genes they control that is required for enzyme production

The operon for tryptophan in the E. coli

The protein that switches off the trp operon

The protein that binds to the operator and blocks attachment of RNA polymerase to the promoter, preventing transcription of the genes

The gene that produces the repressor; is located some distance from the operon and has its own promoter

A small molecule that cooperates with a repressor protein to switch an operon off

Operon that is usually on but can be inhibited when a specific small molecule binds allosterically to a regulatory protein

Operon that is usually off but can be stimulated when a specific small molecule interacts with a regulatory protein

Inactivates the repressor in an inducible operon

A small organic molecule which accumulates when glucose is scarce

A protein that binds to DNA and stimulates transcription of a gene

The expression of different genes by cells with the same genome

Adding an acetyl group to a histone; promotes transcription by opening up the chromatin structure

Enzymes adding methyl groups to certain bases in DNA, usually cytosine; causes genes not to be expressed

Inheritance of traits transmitted by mechanism not involving the nucleotide sequence itself

Cluster of proteins that assembles on the promoter sequence at the "upstream" end of the gene

Segments of noncoding DNA that serve as binding sites for transcription factors

Proteins that regulate transciption

Essential proteins required for the transcription of all protein-coding genes

Control elements located close to the promoter

Control elements located far from the promoter

Groups of distal control elements associated with one gene; enhances function or production of proteins coded for by the gene

Proteins that interact with proteins at the promoter to help assemble and position the initiation complex on the promoter

RNA-processing in which different mRNA molecules are produced from the same primary transcript

Small single-stranded RNA molecules capable of binding to complementary sequences in mRNA molecules; either degrades target mRNA or blocks its translation

Class of small RNAs that turn off the expression of genes with sequences related to microRNAs

The blocking of gene expression by siRNAs

Parasitic DNA elements

Type of ncRNAs that induce formation of heterochromatin, blocking expression of transposons

The process by which cells become specialized in structure & function

The development of the form of an organism and its structures

Maternal substances in the egg that influence the course of early development

Cell-surface receptors and other signaling pathway proteins cause changes in target cells by conveying signals

The point at which an embryonic cell is irreversibly committed to becoming a particular cell type

Proteins found only in a specific cell type and give the cell its characteristic structure and function; the outcome of determination

A master regulatory gene and transcription factor that binds to specific control elements in the enhancers of various target genes and stimulates their expression

Cytoplasmic determinants and inductive signals both contribute to the development of a spatial organization in which the tissues and organs of an organism are all in their characteristic places

The molecular cues that control pattern formation; provided by cytoplasmic determinants & inductive signals

Genes that control pattern formation in the late embryo, larva, and adult

Mutations with phenotypes causing death at the embryonic or larval stage

A gene that, when mutant in the mother, results in a mutant phenotype in the offspring, regardless of the offspring's own genotype

Maternal effect genes that control the orientation (polarity) of the egg

"two-tailed" gene

Substances whose gradients establish an embryo's axes and other features of its form

Cancer-causing genes

Normal versions of the cellular genes that code for proteins that stimulate normal cell growth and division

Genes that code for proteins that help prevent uncontrolled cell growth

A G protein that relays a signal from a growth factor receptor on the plasma membrane to a cascade of protein kinases

A tumor-suppressor gene that encodes for a protein that is a specific transcription factor that promotes the synthesis of cell cycle-inhibiting proteins

Cancer results from genetic changes that affect _________

The gene regulation systems that go wrong during cancer are the same systems involved in ______________________

Cancer can be caused my mutations to genes that regulate ______ & ________

__________ are cancer-causing genes

__________ are normal cellular genes that are responsible for normal cell growth and division; expecially important in embryonic development

Proto-oncogenes can be turned into oncogenes in three ways

_________ help prevent uncontrolled cell growth

Proteins that repair damaged DNA and inhibit the cell cycle in the cell-signaling pathway

Protein that functions like molecular ON/OFF switches

Off (inactive)

On (active)

G proteins bind ___________ nucleotides

Overproduction of _______ can interfere with normal cell-signaling

Mutations in the _____ prevent suppression of the cell cycle

______ mutation(s) are needed full-fledged cancer