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.
Knowing how to tell when carrots are ready to harvest is important for getting a good crop. First, consult your seed packet to see how many days it takes your chosen variety of carrots to mature. Baby carrots are usually ready to harvest 50 to 60 days from the planting date. Mature carrots need a few more weeks and are usually ready in about 75 days. Most carrots are ready to harvest when the shoulders are 1/2 to 3/4 inch in diameter, but again, there is much variation depending on the variety.