Botany of Vascular Plants
Homework #5
A. Read chapter 25 (The shoot – Primary structure and development)
B. Answer checkpoint ques%ons (p. 579) # 2 & 3
2. Name the three basic types of organiza%on found in the primary structure of the
stems of seed plants
Con%nuous ring of herbaceous dicots
Separate vascular bundles in a ring of herbaceous dicots (separated by
ground %ssue)
Monocot organiza%on
oVascular bundles sca1ered
oNo secondary growth
oVascular bundles sca1ered throughout the ground %ssue
3. What are leaf traces, and how are they indica%ve of the close rela%onship that
exists between the stem and the leaves?
Leaf traces = at each node when one or more vascular bundle/s extend from
the cylinder in the stem, cross the cortex, and then come into the leaf that are
a1ached to the node.
Leaf trace extends from the connec%on with a vascular bundle within the stem
(stem bundle) and enters the leaf.
Essen%ally, It connects the vascular system of the leaf to the vascular system of
the stem.
C. Answer ques%ons (p 613) #4, 5, 7, 9
4. How might the distribu%on of stomata di>er among the leaves of mesophytes,
hydrophytes and xerophytes?
Mesophytes are plants that need an average amount of water (not too
wet, not too dry). Hydrophytes require a large amount of water or are
en%rely submerged in it. Lastly, Xerophytes grow in are adapted to arid
environments (dry).
Thus, the stomata are distributed in such a way that either allows be1er
reten%on or water, or less.
Submerged leaves of Hydrophytes do not have stomata because they don’t
necessarily need to prevent water loss. They are geAng water constantly.
