Cross section through a Helianthus stem showing a vascular bundle. Contained in this is the phloem (small red circles), xylem (larger red circles) & cambium between the two. Phloem is made up of sieve elements placed end to end so as to form a sieve tube; this is responsible for the translocation of organic substances. Xylem is made up of nonliving vessels (large hollow tubes made from lignified cells placed end to end) & smaller traechids (elongated lignified cells). This tissue is chiefly responsible for the transport of water & minerals from the roots to the leaves. It also contributes to the strength of the stem, along with the collenchyma and sclerenchyma.
px | px | dpi | = | cm | x | cm | = | MB |
Details
Creative#:
TOP22217022
Source:
達志影像
Authorization Type:
RM
Release Information:
須由TPG 完整授權
Model Release:
N/A
Property Release:
No
Right to Privacy:
No
Same folder images: