Shades of blue show climate divisions that had monthly average temperatures below 50Â°F. The darker the shade of blue, the lower the average temperature. Climate divisions shown in shades of orange and red had average temperatures above 50Â°F. The darker the shade of orange or red, the higher the average temperature.
A stroma is the connective, part of a cell, organ or tissue. The  function of a stroma is to hold the cell, organ, or tissue together  and help it maintain form. Edit.
Main function is to bind antigens on microbes before they invade tissues. It aggregates the antigens and keeps them in the secretions so when the secretion is expelled, so is the antigen.