Cell division cycle mutations render the mutants unable to continue the cell cycle. This phenotype creates a paradox where mutant cells must also be grown in the lab to further identify the gene and study the role of the protein. How do you think this problem can be solved?

The main challenge in studying cell cycle mutant cells is that they can't continue the cell cycle on their own. This makes it difficult to grow them in the lab, which is essential for understanding their gene and protein roles.

To overcome this challenge, some possible solutions to grow these mutant cells in the lab can be considered, such as providing external factors to promote cell cycle progression, or using a conditional or temperature-sensitive mutant to control the expression of the mutated gene.

Assess each potential solution and consider its feasibility, cost, and its ability to enable the growth and study of the mutant cells: 1. External factors: It might be possible to provide external support to promote cell cycle progression, such as providing growth factors or hormones. However, this could prove costly and may not work for all types of mutants. 2. Conditional or temperature-sensitive mutant: By using a conditional or temperature-sensitive mutant, we can control the expression of the mutated gene by changing the environmental conditions. For instance, at a permissive temperature, the mutant gene would be functional, allowing normal cell growth. At a restrictive temperature, the mutant gene becomes non-functional, causing the mutant phenotype to be expressed. This method makes it possible to grow the mutant cells under certain conditions while still studying their phenotype under other conditions.

From the available options, using a conditional or temperature-sensitive mutant seems to be the most efficient and reliable method for studying cell cycle mutant phenotypes. It allows for control over gene expression, making it possible to grow and study the mutant cells by simply adjusting experimental conditions.

Now that we have identified a possible solution, it's time to put it into practice: 1. Obtain or generate a conditional or temperature-sensitive mutant cell line with the cell cycle mutation of interest. 2. Grow these cells at the permissive temperature, enabling normal cell growth and division. 3. Once sufficient cells are grown, change the environmental conditions to the restrictive temperature to induce the mutant phenotype. 4. Study the effects of the mutation on the cell cycle and analyze the gene and protein functions under these conditions. By following these steps, it will be possible to grow mutant cells unable to continue the cell cycle, overcoming the paradox and enable further study of the gene and protein's role.