Final answer:
Gene B, with a p-value of 0.01, is more likely to be truly differentially expressed compared to gene A with a p-value of 0.05 since a smaller p-value indicates stronger evidence against the null hypothesis at a typical alpha level of 0.05.
Step-by-step explanation:
When comparing the p-values of two genes to determine which is more likely to be truly differentially expressed between two conditions, the smaller p-value usually indicates a stronger evidence against the null hypothesis. Here, gene A has a p-value of 0.05, and gene B has a p-value of 0.01. Assuming a significance level (alpha, α) of 0.05, for gene A, the p-value equals the α, which suggests marginal evidence against the null hypothesis, while for gene B, the p-value is well below α, indicating stronger evidence against the null hypothesis.
Therefore, gene B is more likely to be truly differentially expressed since its p-value is smaller, implying a more statistically significant difference between conditions X and Y. In scientific research, especially when examining gene expression, a lower p-value generally increases our confidence that the observed effect is not due to random chance.