Cell Biology Exam 4

Answer all  questions

Dr Jeff Patton

1) RNA processing in general is found in prokaryotes and eukaryotes, but
the splicing of messenger RNA is reserved for eukaryotes. In lower
eukaryotes, such as yeast, the number of transcripts that are spliced are
only a small percentage of all the mRNAs transcribed. It has been said
that the ability to splice most of our mRNA gives us metazoans distinct
advantages over lowly bacteria, or yeast for that matter.

Give at least three examples and discuss why or how splicing of
pre-messenger RNA would be advantageous for cells, or if you want, an
organism, or even a species. You should be general, there is no need to
dwell on specific genes, discuss aspects of splicing that are advantageous
in broad terms.


2) Explain how DNA methylation and chromatin remodeling (epigenetic
changes) play a role in the survival of a determined state after mitosis.
You can think of a determined state as a phenotype, such as cells of the
kidney or spleen are "determined" and have a specific set of genes that
are synthesized after mitosis.

 

DR TROY BAUDINO EXAM QUESTIONS

Let’s assume a cell is in G0. What would guarantee it enters the cell cycle only through G1? As G1 prepares for S and G2 prepares for M. Present and explanation for how the cell guarantees the completion of the G phases before it enters S and M phases.

If S was done perfectly, can the cell skip G2 and go directly into mitosis? When a cell is in G2 and finds not all chromosomes are synthesized can it possibly return to S to synthesize the missing chromosomes and re-enter G2?

Is the ploidy level of a cell changed during mitosis? Can haploid cells undergo mitosis? Can diploid cells undergo mitosis?

What are some of the specific types of errors that can occur during the cell cycle? How are these errors identified by the cell and corrected? What happens to the cell if the errors cannot be corrected?

What is apoptosis? Explain the significance of apoptosis in the life of the cell.

This exam is due in one month....March 14 for Dr Patton and March 22nd for Dr Baudino