Plant Anatomy 2006-2007.

Presentation on theme: "Plant Anatomy 2006-2007."— Presentation transcript:

1 Plant Anatomy

2 Basic plant anatomy 1 root root tip root hairs

3 1 Roots Roots anchor plant in soil, absorb minerals & water, & store food fibrous roots (1) mat of thin roots that spread out monocots tap roots (2) 1 large vertical root also produces many small lateral, or branch roots dicots root hairs (3) increase absorptive surface area 2 3

4 Basic plant anatomy 2 root shoot (stem) leaves root tip root hairs
buds terminal or apical buds: located at top/end of stem axillary buds: where branches form leaves mesophyll tissue veins (vascular bundles)

5 Basic plant anatomy 3 root shoot (stem) leaves root tip root hairs
buds terminal or apical buds: located at top/end of stem axillary buds: where branches form leaves mesophyll tissue veins (vascular bundles)

6 Leaves Function of leaves photosynthesis gas exchange transpiration
energy production CHO production gas exchange transpiration simple vs. compound

7 Internal Structure of a Leaf

8 Interdependent systems
Both systems depend on the other roots depend on sugars produced by photosynthetic leaves shoots depend on water & minerals absorbed from the soil by roots sugars water & minerals

9 Plant TISSUES Dermal Ground Vascular epidermis (“skin” of plant)
single layer of tightly packed cells that covers & protects plant Ground bulk of plant tissue photosynthetic mesophyll, storage Do almost all plant life functions Vascular transport system in shoots & roots xylem & phloem

10 Plant CELL types in plant tissues
Parenchyma “typical” plant cells = least specialized photosynthetic cells, storage cells tissue of leaves, stem, fruit, storage roots Collenchyma unevenly thickened primary walls Support growing tissue Sclerenchyma very thick, “woody” secondary walls support rigid cells that can’t elongate dead at functional maturity If I’d only had triplets!

11 Parenchyma Parenchyma cells are unspecialized, thin, flexible & carry out many metabolic functions all other cell types in plants develop from parenchyma

12 Collenchyma Collenchyma cells have thicker primary walls & provide support help support without restraining growth remain alive in maturity the strings in celery stalks are collenchyma

13 Sclerenchyma Thick, rigid cell wall Cells for support lignin (wood)
cannot elongate mostly dead at maturity Cells for support xylem vessels xylem tracheids fibers rope fibers sclereids nutshells seed coats grittiness in pears

14 Structure–Function again!
Vascular tissue vessel elements Xylem move water & minerals up from roots dead cells at functional maturity only cell walls remain need empty pipes to efficiently move H2O transpirational pull vessel element dead cells Aaaah… Structure–Function again! tracheids

15 Phloem: food-conducting cells
carry sugars & nutrients throughout plant sieve tube companion cell sieve plate plasmodesmata living cells

16 Phloem: food-conducting cells
sieve tube elements & companion cells

17 Structure–Function again!
Aaaah… Structure–Function again! Phloem Living cells at functional maturity cell membrane, cytoplasm control of diffusion lose their nucleus, ribosomes & vacuole more room for specialized transport of liquid food (sucrose) Cells sieve tubes sieve plates — end walls — have pores (plasmodesmata) to facilitate flow of fluid between cells. companion cells nucleated cells connected to the sieve-tube help sieve tubes

18 Comparision of Vascular Tissue in Dicots and Monocots IMPORTANT VOCAB
Pith: Ground tissue internal to vascular tissue Cortex: Ground tissue external to vascular tissue

19 Vascular tissue in stems
dicot trees & shrubs monocot grasses & lilies collect annual rings

20 Comparison of Stems

21 Vascular tissue in roots: dicot
phloem xylem

22 Vascular tissue in roots: monocot
xylem phloem

23 Comparison of Roots