Plant Tissues and Organs

Fig. 38.6

Modular construction of a shoot

Basic Plant Morphology TISSUES- a group of cells functioning together in some specialized activity MERISTEMS- a mass of self-perpetuating cells, which are not yet committed to developing into a specialized cell type Terminal meristems- ends of stems, branches and roots Axillary meristems- base of leaves, branches Lateral meristems are parallel to sides of plant parts and increase girth.

Meristem types Primary Secondary Apical Meristems Vascular cambium Cork Cambium

Flowering plants have 3 basic tissue types Dermal Cover surface of plant Protection Ground Vascular Conducting tissue

Dermal Epidermis epidermal cells Periderm cork cells

Fig. 38.12a

Fig. 38.12b

Fig. 38.12c

Vascular Tissue Xylem Phloem Mostly to conduct water and nutrients E.g., roots to shoots Phloem Mostly to conduct sugars, amino acids, etc. E.g., leaves to roots or flowers

Fig. 38.13a

Fig. 4.6

Fig. 4.9

Fig. 38.13b

Fig. 38.14a

Fig. 38.14b

Vegetative Organs Roots Stems Leaves

Function of roots Anchor the plant Absorb water and minerals from soil Storage

Longitudinal section of roots Root cap Zone of cell division Zone of cell elongation Zone of maturation

Cross section of root Vascular bundle (Stele) = contains xylem and phloem Cortex Epidermis Root hairs Absorb water and minerals

Fig. 38.15

Fig. 38.21

Function of Stems support leaves to maximize light absorption part of conduit for transport of water, minerals, and organic solutes storage

Fig. 38.25a

Fig. 38.25b

Woody dicots Discrete vascular bundles replaced by continuous rings of xylem Each ring is xylem produced during one growing season Vascular cambium

Fig. 38.7a

Fig. 38.7b

Stems: Secondary growth Vascular tissue, (xylem) makes up the bulk of the stem Form tree rings

Fig. 38.23

Fig. 38.28a

Fig. 38.28b

Fig. 38.28c

Function of leaves Main photosynthetic structure

Leaf parts Blade Petiole Pair of stipules

Fig. 38.34

Fig. 38.8

Fig. 38.33

Fig. 38.30