You can enter data as mean, SD (or SEM) and n, and Prism can compute two-way ANOVA. It is not possible to compute repeated measures ANOVA without access to the raw data.
Yes, two-way ANOVA is possible if you only have one value for each condition (no subcolumns). In this case, Prism will only be able to compute ordinary (not repeated measures) ANOVA, and will assume that there is no interaction between the row and column factor. It cannot test for interaction without replicates, so simply assumes there is none. This may or may not be a reasonable assumption for your situation
Two-way ANOVA, also called two-factor ANOVA, determines how a continuous response is affected by two factors. For example, you might measure a response to three different drugs at two time points. The two factors are drug and time.
If you measure response to three different drugs at two time points with subjects from two age ranges, then you have three factors: drug, time and age so wouldwant to choose three-way ANOVA.
The term repeated-measures strictly applies only when you give treatments repeatedly to each subject, and the term randomized block is used when you randomly assign treatments within each group (block) of matched subjects. The analyses are identical for repeated-measures and randomized block experiments, and Prism always uses the term repeated-measures.
In the context of two-way ANOVA, a mixed-model is one where one factor is repeated measures and the other is not. Prism can analyze data where neither factor is repeated measures, one of the two factors is repeated measures, or when both factors are repeated measures. Prism 5 could not analyze data where both factors are repeated measures.
No. Your experimental design has three factors: genotype, treatment and time. If you wanted to use ANOVA, you'd need to use three-way ANOVA.
Prism uses the term "cell" to mean the data on one row for one data set. There may be multiple subcolumns side-by-side, so the cell mean is the average of the values in these subcolumns.
Prism cannot run two-way ANOVA with huge data sets and presents an message telling you so. How huge is huge? Details here.