key terms

cell - smallest functional unit of an organism

tissue - material composed of specialized cells and products

organ - collection of tissues with a specific function

system - roots or shoots

plant tissues

dermal tissue - (epidermis) - outer, protective cell layer equivalent to skin

vascular tissue - conducts material throughout the plant equivalent to circular or resp.

ground tissue - any other tissue that is not dermal or vascular

meristematic tissue (meristems) - able to divide and grow

epidermis

• outer layer of cells on plant (roots, stems, leaves, flowers, fruits, seeds)

cuticle - waxy layer covering the epidermis that shows water loss from the plant

vascular tissue

xylem - transports water and minerals up from the roots (only ever moves stuff up)

• dead tissue, acts like a straw

phloem - moves sugars, other compounds throughout plant (can move stuff in any direction)

ground tissue

parenchyma - thin cell walls and very flexible functions

collenchyma - slightly thickened cell walls for structure

sclerenchyma - very thick cell walls fortified with lignin (chief component of wood) for strength

meristematic tissue

apical meristem - tip of a root or shoot for length or height

intercalary meristem - add height in grasses specifically

axillary meristem - produce branches on roots or shoots

secondary meristem - increase width (cambium)

morphology and anatomy

morphology - external form and structure - as visible from the OUTSIDE

anatomy - internal structure - as visible from the INSIDE

roots

root function

1. anchor plant in soil

2. support upright growth

3. absorb minerals

4. store energy reserves

anchor

anchor - plants are sedentary (unable to move)

support

support - good root health is essential to grow strong, tall roots

lodging - plants fall over

root lodging - root damage or improper development

absorb

water and dissolved nutrients enter the root vascular tissue

root hairs are responsible for a majority of plant water and nutrient uptake

storage

roots can be used to store energy needed by the plant later in its life

roots also use energy because they are actively growing (meristems)

root morphology

taproot - obvious ain root with smaller branches

fibrous root - lots of smaller roots with many branches

adventitious roots - grow from odd places on stems, leaves etc

• ex. corn brace/prop roots

• ex. white clover

monocots - fibrous root system

dicots - taproot system

root anatomy

what do roots look like from the inside?

dicot root

epidermis - outer cells taht protect the root(dermal tissue)

cortex - bulk of root structure usually ground tissue ised for storage

endodermis - surrounds vascular tissue in center

pericycle - meristematic tissue along endodermis (source of lateral root)

casparian strip - waxy layer that controls ewater movemet

phloem - living tissye that transports sugars and other compounds

xylem - deas tissye taht acts like a straw and moves water and nutrients up from roots

vascular cambium - meristematic tissue to make new cells

stele - central region containing vascular tissue and pericycle

monocot root

epidermis

cortex

endodermis

pericycle

casparian strip

phloem

vascular cambium

meristematic tissue

pith - central core of ground cells