Quiz 4 Flashcards
The nuclear envelope is continuous with the:
A) rough ER
B) mitochondrial outer membrane
C) plasma membrane
D) Golgi apparatus
A) rough ER
The nuclear lamina binds to:
A) both the inner nuclear envelope membrane and the chromatin
B) Both the inner and outer nuclear envelope membranes
C) the inner nuclear membrane only
D) the chromatin only
A) both the inner nuclear envelope membrane and the chromatin
The major pathways for molecules to pass into and out of the nucleus is through:
A) porin channels in the nuclear envelope membranes
B) nuclear pore complexes
C) diffusion through the membrane bilayers of the nuclear envelope
D) gap junctions between the nuclear envelope membranes
B) nuclear pore complexes
The nuclear localization signal is recognized by and binds to which protein in the process of nuclear protein import?
A) Importin
B) The outer fibril protein
C) Exportin
D) Ran
A) Importin
Export of RNAs from the nucleus occurs primarily by
A) passive diffusion through nuclear pore complexes
B) release from the nucleus when it breaks down at mitosis
C) selective transport through nuclear pore complexes
D) co-transcriptional insertion through protein pores of the nuclear envelope membrane
C) selective transport through nuclear pore complexes
Highly condensed, transcriptionally inactive chromatin is called
A) euchromatin
B) heterochromatin
C) histone-containing chromatin
D) a chromatin domain
B) heterochromatin
Polycomb bodies act on regions of chromatin by
A) forming euchromatin
B) initiating translation
C) silencing gene expression
D) splicing out introns
C) silencing gene expression
Introns can encode
A) small nucleolar RNAs
B) microRNAs
C) sequences that control gene expression
D) all of the above
D) all of the above
Which of the following is the most abundant form of chromatin in the interphase nucleus of the cell?
A) Chromosomes
B) Nucleoli
C) Heterochromatin
D) Euchromatin
D) Euchromatin
Most pseudogenes are thought to have originated via
A) genome-wide duplication and the inactivation of one homolog by mutation
B) reverse transcription of an mRNA and integration of cDNA into a new chromosomal site
C) fusion of a prokaryotic cell with a eukaryotic cell
D) duplication of genes that then became nonfunctional through mutation
B) reverse transcription of an mRNA and integration of cDNA into a new chromosomal site
Kineticores are the
A) structure at the base of cilia and flagella
B) sites of spindle fiber attachment to chromosomes
C) regions where two chromosomes remain attached during mitosis
D) same as centromeres
B) sites of spindle fiber attachment to chromosomes
The DNA of eukaryotic cells are wrapped around histones to form structures called
A) centromeres
B) nucleoli
C) nucleosomes
D) nuclear matrices
C) nucleosomes
Telomeres are
A) chromosome structures required for complete replication of linear chromosomes
B) microtubule binding sites in the center of chromosomes
C) sites at the end of chromosomes where DNA replication begins
D) sites at the ends of chromosomes where microtubules bind
A) chromosome structures required for complete replication of linear chromosomes
What might be a plausible reason for why mammals have so many more lncRNA than plants or simpler eukaryotes?
A) Mammals are generally larger
B) Mammals actually have less non-coding RNA than bacteria
C) Mammals are more evolved and are more complex, both biologically and behaviorally
D) Mammals are generally more intelligent
C) mammals are more evolved and are more complex, both biologically and behaviorally
A tumor promoter is a type of carcinogen that
A) causes cells to remain in Go of the cell cycle
B) increases chromosomal stability
C) induces apoptosis of healthy cells
D) increase cell proliferation
D) increase cell proliferation
The RNA viruses that most commonly pick up cellular oncogenes are the
A) retroviruses
B) HIV viruses
C) adenoviruses
D) papilloma viruses
A) retroviruses
The most frequently encountered oncogene in human tumors is
A) myc
B) fos
C) ras
D) src
C) ras
What normal cellular process would be affected in a cell line in which MDM2 was mutarted?
A) Apoptosis
B) cAMP signaling
C) Hypermethylation
D) Terminal differentiation
A) apoptosis
The normal function of the tumor suppressor protein Rb is to
A) inhibit Ras
B) Inhibit progression through the G1 restriction point
C) inhibit Cdk4/cyclin B activity
D) induce apoptosis
B) inhibit progression through the G1 restriction point
Nuclear proteins that are stripped of their nuclear localization signal and injected into the cytoplasm of cultured cells will localize
A) in the ring around the outside of the nuclear envelope
B) in the cytoplasm
C) extracellularly
D) in the nucleus
B) in the cytoplasm
