Ch. 10: The Nucleus Online Quiz (MC) Flashcards
What is the average number of replication forks per DNA replication cluster in a mammalian cell nucleus?
Approximately ___.
20
Most snoRNAs function as ___ RNAs.
guide RNAs
The nuclear pore complex of proteins is estimated to have a mass about ___ times that of a ribosome.
30
The nuclear basket protein complex is a component of the nuclear pore complex found ___ ___ ___.
inside the nucleus.
Which of the following is a possible intermediate during pre-rRNA processing?
An RNA molecule containing ___ + ___ rRNAs.
5.8S + 28S rRNAs
Initial steps in the functional assembly of snRNPs occur in the ___.
cytoplasm
Protein transport into the nucleus occurs by selective transport through ___ ___.
nuclear pores
Ribosomes contain one copy each of 5.8S, 18S, and 28S rRNA. The major mechanism ensuring that each is produced in equal molar amounts is the grouping of the DNA sequences encoding each rRNA into a ___ ___ ___.
single rRNA gene
Which of the following factors contributes to the comparative ease of determining how pre-rRNA is processed?
A. The abundance of rRNA genes
B. The abundance of ribosomes (5–10 million) that need to be synthesized per cell cycle
C. The grouping of rRNA genes into discrete nuclear subcompartments, the nucleoli
D. All of the above
D. All of the Above
snRNPs which are responsible for pre-mRNA splicing are assembled and stored in both ___ ___ and ___.
Cajal Bodies and Speckles
Altered gene expression is one possible explanation for the phenotypic consequences of nuclear lamina diseases. The other is ___ ___.
mechanical stress
An important step in the import of the transcription factor NF-κB into the nucleus is regulated by a ___.
protease
