answer; ////mantle; /////////////////is your answer
cortex, in plants, tissue of unspecialized cells lying between the epidermis (surface cells) and the vascular, or conducting, tissues of stems and roots. cortical cells may contain stored carbohydrates or other substances such as resins, latex, essential oils, and tannins.
i'm pretty sure that the tubes are known as "xylem"
pro - asp - gly - lys
a)ccc - aau - caa - gaa
b)ccc - gau - ggg - caa
c)uuc - gau - aag - aau
d)cca - gac - ggc - aaa