Describe the Histogen concept of Apical
meri-stems (Diagram very
essential)​

plant development

analysis has led to the histogen theory, which proposes that the three principal tissues of the root—vascular cylinder, cortex, and epidermis—originate from three groups of initial cells, or histogens, in the apical meristem—plerome, periblem, and dermatogen respectively.

Explanation:

I think. Doesn't make sense why you put this into Spanish, but whatever. Hope that this helps you out! :)

i would say "están" :

the anwser might be la corbata