Chapter 14 Flashcards
How do guard cells act around the stomata?
When turgid they swell and open. When flaccid they relax and close.
Where does secondary (lateral) growth come from?
Vascular cambium. Production of secondary xylem on inside and secondary phloem on outside of the vascular cambium ring cells.
What is included in bark?
All tissues external to the vascular cambium, including secondary phloem, cork cambium, and cork.
How does wood form?
As secondary growth continues over the years, layer upon layer of secondary xylem accumulates.
What is lignin?
Coating of xylem that gives wood its hardness and protection.
What are the two zones of secondary xylem?
Heartwood (doesn’t conduct water but is central column that supports tree) and Sapwood (upward transport of water and minerals by xylem sap)
What are the 3 basic kinds of plant organs?
Roots (underground) and stems and leaves (shoots above ground)
What’s the importance of roots and shoots (stems/leaves) systems?
Roots are underground and is where plants get water and nutrients. Shoots are above ground and is where the plant gets CO2 and light energy.
What is apical dominance?
It causes the plant to grow taller at the apical bud instead of wider to increase the plant’s exposure to sunlight.
What are key differences between monocots and eudicots?
1) Monocots have fibrous roots; eudicots have a taproot system 2) Monocots have one cotyledon; Eudicots have two (first leaves that come out of the embryo) 3) Monocots have parallel veins on leaves; Eudicots have netlike veins 4) Monocots have vascular bundles on stems are scattered; Eudicots bundles are in a ring 5) Monocots have one pollen grain opening; Eudicots have three 6) Monocots petal # divisible by 3; Eudicot petal # divisible by 4 or 5
Root hairs are extensions of what?
Individual epidermal cells
What are stolons?
Runners or above ground horizontal stems
What are rhizomes?
Horizontal underground stems
What are tubers?
The ends of rhizomes
Apical meristems
Localized regions of cell division at the tips of shoots and roots that provide for vertical growth.
Stomata
Pores on leaves and organs that allow exchange of carbon dioxide and oxygen. Also major sites for water to leave during evaporation.
Cuticle
Waxed coating on leaves to prevent water loss and act as protection.
Xylem
Vascular tissue from dead cells that flows up to carry water and minerals from high pressure at bottom to low pressure at top during evapotranspiration.
Phloem
Consists of sieve tubes and companion cells that are alive and transport sugar from sugar source to sugar sink.
Why are tracheids, fiber cells, and vessel elements important?
Support and water transport
What are the three basic types of cells in nonmeristematic tissues?
Parenchyma, collenchyma, sclerenchyma
Are parenchyma cells living or dead? Have primary walls or secondary walls?
Living, with thin and flexible primary walls.
What’s the movement of sugars through sieve-tube members by active transport?
Translocation
When the leaf stomata used for gas exchange, including water vapor and that creates a pressure gradient which pulls in more water.
Transpiration
Are collenchyma living or dead? Have primary walls or secondary walls?
Living, with unevenly thickened primary cell walls
Are schlerenchyma cells living or dead? Have primary walls or secondary walls?
Dead, with primary and thickened secondary cell walls strengthened by lignin
Vessel elements and tracheids in the xylem that function for both support and transport are what kind of cells?
Schlerenchyma
What are the three types of primary meristems? P-P-G
Protoderm, Procambium, Ground meristem
What primary meristem produces the outer epidermis to stems and roots?
Protoderm
What type of primary meristem produces the vascular tissues in stems and roots?
Procambium
What type of primary meristems produce the ground tissues of stems and roots?
Ground meristems
What is responsible for the secondary (outward) growth in plants?
Lateral meristems
Other than meristematic tissue, plant organs are compose of what three basic kinds of NON-meristematic tissue?
Dermal tissue, Vascular tissue, Ground tissue
How can plants respond to the loss of various parts due to disease, weather, or predators?
They regrow the parts because they are modular organisms that have indeterminate growth.
In stems, what does the cork and cork cambium form?
Periderm
The vascular cambium and cork cambium are what type of meristems?
Lateral meristems
Layers upon layers of scondary xylem form over time and harden to produce what tough tissue?
Wood
What produces cork cells and secondary cortex cells?
Cork cambium
What does the periderm along with the secondary phloem form?
Bark
What cells have large amounts of waxy materials that act as a physical barrier to damage in trees?
Cork
What’s the outer skin of the plant?
Epidermis
What waxy substance forms the cuticle, which helps the shoot system retain water?
Cutin
What is the portion of the stem from which leaves and buds and branches arise?
Nodes
What is the portion of the stem that lies between two nodes?
Internode
What are slightly raised circular or elongated slit-like structures on the bark of young woody twigs that function in gas exchange?
Lenticels
These types of sclerenchyma cells are specialized entirely for support.
Fibers and sclereids
These cells assist sieve-tube members in maintaining cell metabolism and function.
Companion cells
Xylem and Phloem. Living or dead?
Xylem are dead cells and Phloem are living cells
What cells make up a phloem tube and are attached to companion cells?
Sieve-tube members
_____ are long, thin xylem cells with tapered ends; _____ are generally wider, shorter, thinner-walled and less tapered xylem cells.
Tracheids; Vessel elements
These cells are produced from the vascular cambium as complete rings or cylinders of conducting tissue.
Secondary xylem and secondary phloem
Buds found at the tips of stems
Apical (terminal) buds
Buds found in the axils of leaves at the nodes
Axillary (lateral) buds
What consists of the primary xylem, primary phloem, and vascular cambium?
Vascular tissue
Multi-layered, complex tissue that originates from the ground meristem.
Cortex
Annual rings of the xylem are composed of this
Spring wood and summer wood
Small hairs extending from the epidermis that function for water absorption, defense, or light reflection
Trichomes
Lighter streaks of parenchyma cells radiating outward fromthe center of the trunk, across the annual rings. They allow the lateral conduction of water and nutrients across the stem.
Rays
Stems consisting of a collection of modified leaves surrounding a short stem, like that of the onion
Bulbs
The thin, flattened, photosynthetic part of the leaf
Blade
The stem-like stalk of a leaf that attaches the blade to the node
Petiole
Where one or more layers of elongated photosynthetic parenchyma cells lie adjacent to the epidermis on the top part of the leaf
Palisade mesophyll (parenchyma)
The loosely organized photosynthetic parenchyma cells between the palisade mesophyll and the epidermis on the bottom part of the leaf
Spongy mesophyll (parenchyma)
The process of leaf shedding that deciduous plants go through
Abscission
The first of the vegetative organs to emerge from the germinating seed
primary root
Root system with large primary root and many smaller lateral roots
tap root
Root system with no distinct tap root
Fibrous
The innermost layer of cortex cells characterized by Casparian strips on their transverse and radial walls
endodermis
Area of cell wall that has been secondarily thickened with lignin and waterproofed with suberin
Casparian strip
Waxy material impervious to water and dissolved minerals that waterproofs the Casparian strip
suberin
Layer of cells derived from the procambium that are just inside the endodermis. They’re relatively unspecialized parenchyma cells that retain a potential to undergo cell division.
pericycle
Central region consisting of parenchyma cells in monocot roots
pith
The central part of the root that includes all tissues inside the cortex, including the pith in monocots
stele
The outermost layer of cortex cells
hypodermis (exodermis)
Underground stems used for food storage
corms
Porous end walls between cells along the length of the sieve tube, allowing unimpeded movement from one cell to the next
sieve plates
