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.