Answer to Question #59109 in Cell Biology for Tracy Guido

Question

64.
Each eukaryotes can regulate gene expression. Determine which of the five mechanisms each example represents. Not all examples will be used.
changes in chromatin structure Activity of transcription apparatus RNA processing RNA interference Initiation of translation
1. the 3 end can be cleaved to produce different transcript lengths before addition of the poly-a-tail. 2. acetylation of histones facilitates transcription. 3. The RISC degrades mRNA complexed with miRNA or siRNA. 4. Transcriptional repressors compete with activators for DNA binding sites. 5. RNA granules control the availability of mRNA for translation. 6. Gene inversion does not cause a loss of genetic information but may affect regulation of the inverted genes.

68. Which of the following factors determine cell fate?
cytoplasmic determinants
genome sequence
signals from neighboring cells
cell location in the embryo

Answer 1

64. changes in chromatin structure 2. acetylation of histones facilitates transcription.
Activity of transcription apparatus 4. Transcriptional repressors compete with activators for DNA binding sites.
RNA processing 1. the 3 end can be cleaved to produce different transcript lengths before addition of the poly-a-tail.
RNA interference 3. The RISC degrades mRNA complexed with miRNA or siRNA
Initiation of translation 5. RNA granules control the availability of mRNA for translation.

68. cytoplasmic determinants (grey crest for example), signals from neighboring cells (can stop cell division or stimulate it), cell location in the embryo (determine, if the cell will undergo apoptosis or in which cell type will develop)