The Biology Directorate is now accepting research proposals again, and accepting them at any time (i.e., no preliminary proposals or deadlines).
Instructions for submitting to the Developmental Systems Cluster are at: https://www.nsf.gov/pubs/2018/nsf18586/nsf18586.htm
You can find other programs’ solicitations at the BIO home page: https://www.nsf.gov/dir/index.jsp?org=BIO