Download Plant Structure and Growth

Plant Structure and Growth
&
Plant Reproduction
Emma Whisted
Plant Structure and Growth
Dicotyledonous Stem and Leaf Structure
Epidermis: surface of the stem made of a number of layers
often with a waxy cuticle to reduce water loss.
Stem
Cortex Tissue: Forming a cylinder of tissue around the outer
edge of the stem. Often contains cells with secondary
thickening in the cell walls which provides additional
support.
Vascular bundle: contains xylem, phloem and cambium
tissue.
Xylem: a longitudinal set of tubes that conduct water from
the roots upward through the stem to the leaves.
Phloem: (sieve elements) transports sap through the plant
tissue in a number of possible directions.
Vascular cambium: a type of lateral meristem that forms a
vertical cylinder in the stem. The cambium produces the
secondary xylem and phloem through cell division in the
vertical plane.
Pith: In the center of the stem; composed of thin walled
cells called parenchyma. In some plants this section can
degenerate to leave a hollow stem.
Plant Structure and Growth
Dicotyledonous Stem and Leaf Structure
Cuticle: a waxy layer which reduces water loss
through the upper epidermis.
Leaf
Upper epidermis: a flattened layer of cell that
forms the surface of the leaf and makes the
cuticle.
Palisade Layer: the main photosynthetic region of
the leaf.
Vascular bundle: contains the transport system
and vascular meristem tissue (x-xylem, pphloem).
Spongy mesophyll: contains spaces that allows
the movement of gases and water through the
leaf tissue..
Lower epidermis: bottom surface layer of tissues
which contains the guard cells that form each
stoma.
Plant Structure and Growth
Dicotyledonous vs. Monocotylonous plants
Plant Structure and Growth
Distribution of Tissues in the Leaf
(a)Phloem: transports the products of
photosynthesis (sugars, amino acids).
(b)Xylem: transports water and minerals into the
leaf tissue from the stem and roots.
(c)Epidermis: produces a waxy cuticle for the
conservation of water.
(d)Palisade: layer which is the main photosynthetic
region.
(e)Spongy layer: creates the spaces and surfaces for
the movement of water and gases.
(f)Lower epidermis: contains the stomata pores
which allow gas exchange with the leaf.
(g)xylem and phloem: combine in the vascular tissue
to provide support to the leaf.
Plant Structure and Growth
Apical and Lateral Meristems
Apical:
Primary growth; found at the tip of the root
and the shoot, adding growth to the plant in
these regions.
Lateral:
Also known as Cambium. Is the source of cells for
secondary growth. Two types- cork cambium and
vascular cambium.
Cited websites:
1. http://click4biology.info/c4b/9/plant9.1.htm