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Structure - Shoots

 

	Where does most of the elongation of the stems occur?
	internodes

	What do you expect to find at a node?
	leaves axillary buds sometimes roots or stipules

	What is the origin of the pattern of leaf arrangement on a stem?
	the way that primodia are developed on the apex (phyllotaxy)

	How does the pattern of cell division in the tunica relate to the structure of the tissue to which it mainly contributes?
	Division at right angles to surface (periclinal) lead to spreading sheat of cells (epidermis).

	What kinds of primordia develop from the shoot apex?
	leaf and bud

	Can you distinguish a zone of cell division and a zone of elongation in the shoot apex?
	no

	What is an intercalary meristem?
	Intercalary meristems continue stem elongation after other parts have matured. It would be at the base of a stem or leaf, allowing new tissue to be added from below.

	What separates the pith and cortex in a dicot stem?
	a ring of vascular tissues

	How would you distinguish a dicot with discrete bundles from a monocot?
	In dicots the bundles are in a ring. In monocots the bundles are scattered.

	What are 'open' and 'closed' vascular bundles?
	Open vascular bundles have cambium and the possibility of further xylem and phloem.   There is no cambium in closed vascular bundles.

	How does a pith parenchyma cell get its oxygen?
	through intercellular spaces which lead out to stomata

	What happens to the vascular tissue near a node?
	strands pass out to leaf and bud, leaving "gaps" in the stem

	What is interfascicular cambium?
	a line of meristematic cells joining vascular bundles.

The primary meristems of the plant are: the tunica and corpus root apical meristem and shoot apical meristem protoderm, procambium, and ground meristem

These are regions of the shoot apical meristem; the primary meristems are those responsible for growth of primary tissues of the plant and are a little way back from the apex of root and shoot.   The primary meristems are those responsible for growth of primary tissues of the plant and are a little way back from the apex of root and shoot.   Yes the protoderm gives rise to the epidermis of root and shoot, the procambium to the xylem and phloem in root and shoot; the ground meristem produces the cortex in root and shoot and the pith in the shoot.

	In dicot stems the vascular bundles tend to have: xylem on the outside phloem on the outside no meristematic cells
	Wood is derived from the xylem and forms in the middle of the stem.   Phloem is usually towards the outside of the stem (and consequently on the lower side of the veins in leaves).   Dicot vascular bundles contain cambium.

	Monocot vascular bundles are called "closed" because they: are enclosed by a ring of fibers have no cambium are blocked at the ends
	This may be true but is not the reason for the term "closed".   An "open" bundle is one that has cambium and the potential for future growth. Monocots lack this feature and so are termed "closed".   No, vascular bundles in monocots are not blocked at the ends.

	A vertically compressed underground stem storage structure is a: corm rhizome stolon
	Corms are often confused with bulbs but even when they are covered with scale leaves they turn out to be mostly stem. Examples are Cyclamen and Gladiolus.   A rhizome is a horizontal underground stem that is enlarged for food storage.   A stolon is a horizontal stem growing along the ground and rooting at the nodes to produce new plants.

	Fusiform initials give rise to: lenticels ray parenchyma vessel and sieve elements
	Fusiform initials are part of the vascular cambium; lenticels are a derivative of the cork cambium.   As you might expect, ray initials give rise to ray parenchyma.   Fusiform initials are elongated and it makes sense that they should give rise to vessel and sieve elements

	A major difference between dicots and conifers is that conifers lack: vessel elements cork cambium sieve elements
	Yes, conifer xylem contains tracheids, but no vessels.   Conifers have bark, just like dicot trees and it is formed by a cork cambium   Sieve elements are an indispensable feature of vascular plants in general; how could conifers live without them?

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