CSF Exam 3 Practice

Which of the following are components of Chargaff's rules of bases? 

All of the above

Heterochromatin is highly ________, thus constitutive heterochromatin plays a(n) ________ role and facultative heterochromatin functions in ________.

compacted; structural; regulation of gene regulation

You are using genetic engineering to design a protein that needs to be synthesized in the cytoplasm and then localized in the nucleus of the cell. To accomplish this, you could add ________________________________. 

a DNA sequence for a nuclear localization signal into the DNA that will be present in the mature protein.

DNA helicase

Unwinds double-stranded DNA

gyrase/topoisomerase

nicks DNA ahead of replication fork to relax supercoiling in DNA

Primase

Synthesizes RNA primers for DNA synthesis

DNA Polymerase III

elongates DNA strand

DNA Ligase

covalently links breaks in the sugar-phosphate backbone

In DNA replication, the leading strand of DNA ________, while the other newly forming strand, called the lagging strand, ________.

is synthesized as a continuous chain; is formed in a series of short, discontinuous fragments

Which of the following DNA repair mechanisms is most prone to error?

nonhomologous end joining (NHEJ)

The C-terminal tail of RNA Polymerase II has multiple functions during transcription. What aspect of the C-terminal tail is responsible for determining the different functions?

phosphorylation state of the tail

You are studying a eukaryotic gene whose initial transcript is 1500 nucleotides in length. The mature mRNA derived from the gene is 1200 nucleotides in length. What is the most probable reason for the discrepancy?

removal of introns

With regard to RNA polymerase proofreading ability, which of the following is true?

RNA backtracking can remove noncomplementary nucleotides.

You have isolated a piece of DNA that you believe contains an interesting gene. Using a mix of RNA polymerase and ribonucleotides, you perform in vitro transcription. However, even though all of your controls work, no mRNA is created from your DNA fragment. Working backward, you note that your DNA preparation removed approximately 250 base pairs from the 5' end of the gene. The most likely explanation is that during DNA preparation

the promoter was removed

You are attempting to determine which step of prokaryotic translation a new antibiotic inhibits. You have determined that the antibiotic interacts with a translational factor but need to identify which one. If the new antibiotic interferes with elongation, which of the following functions could the antibiotic disrupt?

EF-Tu interaction with an aminoacyl-tRNA

Each of the following is an activity of a microtubule motor protein during mitosis except

extending astral microtubules during anaphase

Which of the following occurs during prometaphase (late prophase)?

nuclear envelope fragmentation

Which of the following is true regarding the difference between mitosis and meiosis:   

homologous chromosome pairs are separated in anaphase I of meiosis.