Exam 15: Gene Regulation in Prokaryotes

Normal alleles of tumour-suppressor genes function to encode proteins that

A temperature-sensitive screen is completed by treating cells with mutagen,replica plating,and then selecting for growth in permissive and restrictive temperatures.

______________________ are mutant forms of normal genes that act dominantly to predispose a cell to a cancerous phenotype.

Of the approximately 300 cell types,some,once terminally differentiated,never divide again even if life continues for nearly a century.

The retinoblastoma (Rb)protein regulates progression into S phase by regulating ___________ activity.

A programmed cell change that results in cell death is referred to as

_______________________ are proteins that span the plasma membrane and transmit signals from outside the cell into the cytoplasm.

Cells that have migrated from a tumour and invaded a distant tissue are said to have

Define: Tumour-suppressor gene

DNA damage activates the p53 transcription factor,which in turn induces expression of the p21 gene.

The temperature at which a cell with a temperature-sensitive mutation is unable to survive is considered the ___________ temperature.

Using yeast,you wish to test the hypothesis that two new temperature-sensitive mutations you have isolated are involved in different steps of the cell cycle.Describe the experimental setup necessary to do so.

Cell-surface receptors function to transmit signals from the outside of the cell into the cytoplasm.Name the three protein domains that are responsible for receptors to accomplish this signal transmission.

You wish to determine which genes are aberrantly expressed in a certain type of cancer.How would you measure a possible transcription difference on a genomic level between the cancer cells and normal cells?

Which of the following is not a common consequence of mutations that eliminate cell-cycle checkpoints?

In the cell cycle of Saccharomyces cerevisiae,the appearance of a bud on the surface of a cell indicates that the cell

A patient presents with cancer tumours in several organs.You genotype for several genes often related to the causation of cancer and find that cells from each disparate tumour have the same genotype for all of the genes tested.How do you interpret this data?

Which of the following does not function to reduce the likelihood of a cell becoming cancerous?

Define: Oncogene

Cell-cycle check points are arrests to the cell cycle in which the integrity of the genome and cell-cycle machinery are "checked" prior to continuing to the next cell-cycle stage.