There is a set of tumors,each one includes five features, which relate to one gene type result.

Tumor Feature 1 ... Feature 5 Gene type
1 Type 1
2 Type n
... ...

Now I need to use chi-square test to analyze the correspondence between the five features and the gene types. I build the H0: there is no relation between features and type response.
My question is how to use chi-square test in R software to do the job? Is there any requirement for the number and frequency of the data?
Thank very very much and much!