There are many different cell types and sub-types involved in the immune system. Some of the main types include: Lymphocytes: are white cells which circulate between blood and lymph. They play an important role in fighting infection.
After about 50 to 60 days, beets are ready to harvest. Not only can the roots be dug up and chopped to add flavor to a meal, but the greens of the beets can be harvested periodically and put in salads. Given how well these beets fare in different weather conditions, they can be grown several times in a summer.
Harvest In general terms the plants should be ready after 8 weeks of bloom. You can tell they are getting ready when the majority of white hair on the buds starts to change colour (usually grey, sometimes red or purple). When around 80% of hair changes colour the plants are ready to be harvested.