Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
20 Cards in this Set
- Front
- Back
Meristems
|
Small clumps of undifferentiated cells from which new cells arise
Analagous to stem cells in animals |
|
2 types of meristems for growth
|
Apical meristems: primary growth at tip of stem or root
Lateral meristems: secondary growth to increase girth |
|
3 types of Plant Tissue
|
Dermal
Ground Vascular |
|
Plant Tissue: Dermal
|
Specialized cells for protection & absorption
|
|
Plant Tissue: Dermal: Cells
|
epidermal cells- outer covering of entire plant body
guard cells – open & close the stomata trichomes – hairlike outgrowths that cool plant surfaces, reduce evaporation, & sometimes secrete toxins root hairs – increased surface area for absorption |
|
Plant Tissue: Ground
|
most of plant body
|
|
Plant Tissue: Ground: Cells
|
Parenchyma cells: living protoplasts, food & water storage, photosynthesis, & secretion
Long-lived (up to 100 years) Collenchyma cells: living protoplasts, provide flexible support Sclerenchyma cells: nonliving protoplasts at maturity, strengthen plant tissues |
|
Plant Tissue: Vascular: 2 Types
|
Xylem: transports water & solutes from roots
Phloem: transports food (sugars) from photosynthetic sites |
|
Plant Tissue: Vascular: Xylem
|
Vessels: continuous tubes formed from dead, hollow cells
Tracheids: dead, tapered cells that overlap |
|
Plant Tissue: Vascular: Phloem
|
Sieve-tube members: elongated cells with clusters of pores for food transport, each with a (companion cell)
Companion cell: parenchyma cell that performs metabolic functions for specialized sieve-tube members |
|
3 Plant Organs
|
Roots
Stems Leaves |
|
Roots
|
Root cap – composed of columella cells
Protect meristem as root grows through soil and act as gravity sensors Zone of cell division – mitotic divisions Zone of elongation – cells elongate (which lengthens the root) and vacuoles swell Zone of maturation – cells differentiate (epidermis, xylem, phloem, etc.) |
|
Modified Roots
|
Pneumatophores – outgrowths of underwater roots that acquire oxygen
Prop roots – for support against the wind Contractile roots – spiral into the soil to pull plant deeper for temperature control Food storage – sweet potatoes, carrots, beets, radishes, etc. Parasitic roots – penetrate & feed off other plants Water storage – in arid regions Buttress roots – support in tropical trees |
|
Stem Structures
|
Apical meristems at tip of stem
Apical meristems at junction of leaf & stem Form buds which can: Repeat the growth pattern of the terminal meristem Make flowers directly Lenticels – for gas exchange into stem tissue |
|
External Leaf Structure
|
Simple leaves – undivided blades
Compound leaves – 2 or more leaflets - Pinnately – leaflets in pairs along an axis - Palmately – leaflets radiate from a common point |
|
Leaf Arrangements
|
Alternate (spiral)
Opposite – 2 leaves per node Whorl – circle of leaves at same node |
|
Internal Leaf Structure: Epidermis
|
Transparent epidermis around entire surface
Upper surface has a waxy cuticle Lower surface has many stomata (for gas & water exchange) |
|
Internal Leaf Structure: Mesophyll
|
Mesophyll –between upper & lower epiderm.
Palisade: tightly packed cells with chlorophyll Spongy: loosely packed cells with extracellular spaces for gas & water exchange |
|
Internal Leaf Structure: Vascular Tissue
|
xylem & phloem
|
|
Modified Leaves
|
Bracts: colored leaves that mimic flower petals
Spines: cacti Reproductive leaves: produce tiny “plantlets” which can grow into new plants (Kalanchoe) Window leaves: transparent leaves that allow light to penetrate & reach chloroplasts underground Shade leaves: more surface area but thinner than those leaves on the same plant in direct sunlight Insectivorous leaves: secrete enzyme to digest insects |