I took genetics lecture and lab almost 2 years apart because of scheduling issues. The disadvantage is that I had to go back and review topics as we applied them in lab. But I feel the advantages are great because it forced me to basically “learn” the topics for a second time, making them stick better than just one pass through (if I had taken the components together). So ultimately I don’t think it matters - you just might have to factor in a little extra time for the lab.