Assignment

Explain how communication within or between cells regulates gene expression in the following cases:

• - Cytokines regulate gene expression to allow for cell replication and division.

• - Mating pheromones in yeast trigger mating gene expression.

• - Levels of cAMP regulate metabolic gene expression in bacteria.

• - Expression of the SRY gene triggers male sexual development pathway in animals.

• - Ethylene levels regulate production of different enzymes, allowing fruits to ripen.

• - Seed germination and gibberellin.

Explain how signal pathways mediate gene expression, including how this process can affect protein production in:

• - Mating pheromones in yeast trigger mating genes expression and sexual reproduction.

• - Morphogens stimulate cell differentiation and development.

• - Changes in p53 activity can result in cancer.

• - HOX genes and their role in development.