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.
Beets and beet greens are rich sources of iron and important vitamins. You can plant beets beginning in early spring and up until about 90 days before the first frost. It takes about 55 to 60 days for the roots to mature.