Embryonic regions; site of cell division, where cells called 'intials' divide during Mitosis, one remains as an initial in the meristem, while the other 'the derivative' can eventually differentiate into any plant tissue
What are the 3 primary meristems that the apical meristems give rise to?
-Is also the route of movement for most plant viruses
-Parenchyma & fibers are also present
Phloem is composed of [BLANK] in gymnosperms
Sieve Cells in Gymno
Phloem is composed of [BLANK] in Angiosperms
Sieve tubes in Angio
Types of Dermal tissue
Epidermis & Periderm
Description/ Function of the Epidermis
Constitutes the dermal tissue system of leaves, floral, fruits & seeds, stems & roots until secondary growth has occured
*lacks chloroplasts so light may penetrate the leaf*
The walls of aerial parts of the epidermis are covered with a [BLANK] to minimize water loss
Cuticle
The epidermis may contain [BLANK] which make up stomata
Guard cells
The epidermis may contain [BLANK] aka leaf hairs
Trichomes
Description/ Function of Periderm
Secondary protective tissue
-commonly replaces the epidermis in stems & roots that undergo secondary growth
[BLANK] are found loosely arranged & provide aeration of the internal tissues of roots and stems
Lenticels
Hypothesized functions of trichomes
1. Defense against herbivores
2. Secrete salty solutions to prevent the accumulation of detrimental salt in salty environments
3. The absorption of water & minerals
4. Reflect solar radiation
5. Temp regulation
6. Prevents water loss in arid conditions
Primary structure of roots
Anchorage and absorption & conduction and storage
(T/F) Only fine young roots with with living epidermis can absorb water and minerals
TRUE
Define Taproot
Primary root, grows downward, giving rise to lateral roots
What kind of roots absorbs soil water
...?
Define Mucilage sheath
A highly hydrated polysaccharide that lubricates the root during its passage through the soil
Tubular extensions of epidermal cells which greatly increase the absorptive surface of the root.
Most of the absorption of water and nutrients occurs here
Root hairs
What is the name of the ground tissue in roots?
The Cortex
Define/ Function of the Endodermis
1. A single layer of cells that borders the cortex of a root.
2. Helps the roots regulate what gets into the vascular core
Define/ Function of the Casparian Strip at the endodermis
1. Band-like portion of the primary wall thats impregnated with suberin
2. Hydrophobic so it prevents water from flowing across cell membranes and walls
3. Acts as a filter for solutes going from the soil to the xylem & throughout the plant
Aerial roots vs air roots
Aerial roots are produced from aboveground structures (prop & stilt roots)
Air roots (pneumatophores): grow upwards against gravity
How many kinds of leaf shapes are there worldwide?
182,707
A compound leaf is..
Composed of several leaflets which are joined to a single stem
Ex) Palm leaf
A simple leaf is...
made of a single leaf blade connected to the stem via the petiole
Ex) Oak leaf
Define/ Function of a petiole
Connects the leaf to the stem
Define/ Function of a leaflet
One part of a compound leaf
Define/ Function of a Rachis
Main stem of a compound leaf, the petiole connects to this
Leaf veins contain the xylem and phloem which are enclosed by [BLANK]
Bundle sheaths
Typical angiosperms leaves are composed of [BLANK]
A hierarchical vein network
[BLANK] are visible to the naked eye, include midrib (first order), secondary and branching tertiary veins. Are important for drought tolerance
Major veins
[BLANK] make up the bulk of the entire vein length of the leaf
Minor veins
Species with high minor vein length tend to have [BLANK] rates of transpiration & photosynthesis
Higher
Leaves from high light areas are expected to have low or high MINOR vein length per leaf area
High
Leaves from dry areas are expected to have high or low MAJOR vein length per area
LOW
[BLANK] in the leaf is comparable to the endodermis in roots although not all species have a casparian-like structure in leaves
Bundle sheath
Define/ Function Bundle sheath cell walls
Walls that contain lignin, which surrounds the entire cell wall
Describe the pathways of water movement through leaves
1. Water moves through the xylem
2. Exits the xylem
3. Then to the bundle sheath & mesophyll until it evaporates & diffuses out of the stomata as vapor
Characteristics of the xerophyte leaf
1. Thick cuticle
2. Multiple layers of epidermis
3. Stomata and trichomes are resticted to invaginated portions of stomatal crypts
Characteristics of an aquatic leaf
1. Aerenchyma (allows leaf to float) for gas exchange
2. Stomata on upper epidermis
Angiosperm dicots & gymnosperm can undergo secondary growth from the [BLANK] which give rise to wood
Vascular cambium
[BLANK] are growth increments in secondary xylem & phloem related to seasons
-These are also produced by abrupt environmental changes like drought or fire
Growth rings
[BLANK] are modified stems & are found in grapes
Tendrils
[BLANK] are modified stems that resemble foliage leaves
Cladophylls
Definition: Modified leaves; Defense against Herbivores
Spines
Definition: Modified Stems; Defense against Herbivores
