Practical #2 - Plant Form and Function Flashcards
1
Q
What are the 3 basic types of cells in nonmeristematic tissues?
A
- Parenchyma
- Collenchyma
- Sclerenchyma
2
Q
What are the attributes of a parenchyma cell?
A
- forms much of the ground tissue
- mesophyll of leaves, cortex and pith of stems
- Living when functionally mature
- Aid in metabolism, and storage.
- Most epidermis and edible parts of fruits are parenchyma cells
- Thin and flexible primary walls
- made of cellulose
- Developing plants use these before specializing further
3
Q
What are the attributes of a Collenchyma Cell?
A
- Provide support for young stems
- Support vascular tissues, leaf veins, petioles
- Alive at functional maturity
-
Thicker primary walls than parenchyma cells
- composed of cellulose and pectin
- Unevenly thickened
- Think of strings in the stalks of celery
4
Q
What are the attribute of sclerenchyma cells?
A
-
thick secondary walls
- for support in non growing regions of the plant
- made of cellulose and ligning
- Cannot elongate
- dead at functional maturity
- Examples
- vessel elements, tracheids
- fibers and sclereids
5
Q
What is a meristemic cell and what are the 3 types?
A
- A cell that retains the capacity to undergo cell division
- apical meristem
- primary meristem
- lateral meristem
6
Q
What is an apical meristem?
A
- locaed on the tips of young shoots and roots
- Increase the length
- these produce the primary meristem and lateral meristems!
7
Q
What are Primary Meristems?
A
- consist of three kinds which are produced by teh apical meristem
- Primary meristem is responsible for primary growth (Increase in the length of stems and roots)
- 3 types:
- protoderm
- Procambium
- Ground Meristem
8
Q
What are the functions of the Protoderm, Procambium, Ground Meristem?
A
-
Protoderm
- produces the otuer epidermis to stems and roots
-
Procambium
- produces the vascular tissues in stems and roots
-
Ground Meristem
- produces the ground tissues in stems and roots
9
Q
What is the lateral Meristem?
A
- Increases the girth of indvidual stems and roots, but not leaves
- responsible for secondary growth
- 2 major types
- Vascular cambium
- Cork Cambium
10
Q
What is the Vascular Cambium?
A
- prodcues tissues that increase the girth of the plant
- particularly - secondary xylem and secondary phloem
-
layer and layers of secondary xylem form wood over time
*
-
layer and layers of secondary xylem form wood over time
- particularly - secondary xylem and secondary phloem
11
Q
What is the Cork Cambium?
A
- Acts to produce a thick covering for large stems and roots
- Parenchyma cells in the cortex become he cork cambium
- Produces Cork Cells and Secondary cortex cells
-
Cork Cells
- have a waxy coating that acts as a barrier
- Along with cork cambium form the periderm
- Cortex Cells
-
Cork Cells
12
Q
What produces bark?
A
- Scondary Phloem cells and the Periderm
- Bark replaces the epidermis over time
13
Q
What are the 3 types of nonmeristematic Tissues?
A
- Dermal Tissues
- Vascular Tissues
- Ground Tissues
14
Q
What do Dermal tissues consist of?
A
-
Epidermis
- acts as the outer skin of the plant
- Epidermis produces a wazy substance, cutin, that forms the cuticle.
15
Q
What are the functions of Vascular Tissues? What are the types of Vascular Tissues
A
- Involved in the transport of materials through the plant, upward from roots to stems and leaves and downward from leaves to roots
- 2 types:
- Xylem - carries xylem sap from roots to active tissues of stems and leaves
- Phloem - carries phloem sap from one part of the plant to another
16
Q
What are the 4 external features of a Stem?
A
- Node - portion of the steam from which leaves and buds and branches arise
- meristematic tissues are located here
- Internode - portion of the stem that lies between two nodes
- Lenticels - raised circular slit-like structures on the bark of young woody twigs that funtion in gas exchange
- Buds - undeveloped shoots
- Covered by bud scales
- Terminal Buds (Apical buds)
- Axillary buds (Lateral buds)
17
Q
Epidermis of the stem structure
A
- Single layer of parenchyma cells, derived from the protoderm
- Outer wall covered with waxy substance - cutin, which forms the cuticle
-
Guard Cells surround the stomata…but these are most abundant on leaves
*
18
Q
Stem Cortex structure
A
- multilayered, complex tissue
- Originates from the ground meristem
- consists mainly of collenchyma and parenchyma cells
19
Q
Stem Vascular tissue structure
A
- Primary Xylem, Primary Phloem, Vascular Cambium
- Vascular tissues arise from the procambium
- Normally condensed into bundles
- Vascular cambium is found between the xylem and phloem (fascicular cambium)
20
Q
Pith, Stem Structure
A
- Located in the center of the stem and is composed of parenchyma cells, originating from the ground meristem
- Sometimes they break down leaving the center hollow
21
Q
What are the differences in primary tissues origins between Monocots and Eudicots
A
- In monocots the vascular bundles are scattered thoughout the ground tissue of monocot stems.
- Cortex and pith are indistinguishable, so all tissue derived from the ground meristem are called ground tissue
22
Q
Phloem Transport Structures
A
-
Sieve-Tube Members
- Cells that make up the phloem tube.
- Arranged end to end
- Contain porous end walls sieve plates
- alive at functional maturity
- no nuclei and ribosomes
-
Companion Cells
- adjacent to and connected to sieve-tube members.
- Retain nuclues and alive at maturity
- Assist sieve-tube members in metabolism and function
23
Q
How does Phloem sap move through the plant?
A
-
Translocation
- Sugars are move through active transport into sieve tube members.
- ATP is needed
- Hydrostatic pressure moves the sugary solution
24
Q
How does Xylem Sap move through the plant?
A
-
Transpiration or Evapotranspiration
- Hydrogen bonds between adjacent water molecules occur through the plant to the roots
- As a water molecule evaporates from the stomata of leaves, it “tugs” on the next water molecule to pull it up
- Requires no ATP
25
Q
What are Tracheids and Vessel Elements
A
- Both are involved in moving Xylem sap throughout the plant
-
Tracheids
- long, thin cells.
- Secondary walls are strengthened with Lignin
-
Vessel Elements
- wider, shorter, thinner-walled than tracheids
- Aligned end to end called xylem vessels
26
Q
What is the Interfascicular Cambium
A
- Meristemic tissue develops between the vascular bundles (Phloem and Xylem)
- Becomes continuous with fascicular cambium
- These form a continuous ring around the stem called vascular cambium
27
Q
Where does secondary xylem and phloem originate from?
A
- When the fascicular cambium and the interfascicular cambium fuse to form the vascular cambium…cells produced from this tissue differentiate as secondary xylem and secondary phloem
- These also form a complete ring
- Wood is made of secondary Xylem
28
Q
Where does the cork cambium originate from?
A
-
Cork cambium (also called phellogen) is another lateral meristem that forms from parenchyma of the cortex
- this is outside of the vascular cambium and its derivatives
- The cork cambium, cork and secondary phloem form bark
29
Q
Secondary Growth: Eudicots vs Monocots
A
- Eudictos typically have true secondary growth with vascular cambium, cork cambium, and bark
- Monocots usually dont have secondary growth
30
Q
Describe the difference between Spring Wood and Summer Wood
A
- Due to different climates the xylem forms differently in woody eudictos
- During the spring, they are less dense and larger (Spring Wood)
- During the summer, smaller cells and thicker walls (Summer wood)
31
Q
Describe the process of Secondary growth in Stems.
A
- secondary xylem and secondary phloem form a cork cambium in the outer cortex
- with gives rise to the periderm
-
Cork-cells are made here and are impregnated with compouded called suberin
- waterproofing agen
- Eventually the epidermis and outer cortical layers are dropped off
32
Q
Rays are located in the Xlyem, what do they do?
A
- Allow the lateral conduction of water and nutrients across the stem
33
Q
What is the difference between heartwood and sapwood
A
-
Heartwood - It is the discolored center of a woody stem. The xylem cells have died and stopped working
- Mainly there for support now
-
Sapwood - Outer lighter colored region
- functions in mechanical support and transport
34
Q
Diferrent Types of Stems
A
- Stolon - horizontal stems (like the runners in strawberries
- Rhizomes - underground horizontal stems
- Tendrils - grapes
- Tubers - potatotes
- Bulbs - collection of modified leaves, onions
- Corms - short underground stems for food storage….gladiolus?
35
Q
Describe Leaf Venation
A
- The arrangement of veins, composed of vascular tissues like phloem and xylem, in the blade is called venation
- 2 types:
- Net-like
- Parallel
36
Q
What is the mesophyll?
A
- the phtotsynthetic parenchyma between the upper and lower epidermis of the blade
37
Q
What is Palisdae mesophyll (Eudicots)?
A
- (Palisade parenchyma)
- one or more layer of elongated photosynthetic parenchyma cells lie adjacent to the upper epidermis
38
Q
What is Spongy mesophyll (Eudictos)?
A
- (Spongy parenchyma)
- Loosely organized photosynthetic parenchyma cells between the palisade mesophyll and the lower epidermis
39
Q
Differences between Monocot Leaves and Eudicot Leaves
A
- Monocot leaves
- Stomata are spread evenly on upper and lower surface of the blade
- There is no differntiation into palisade and spongy mesophyll
- Eudicot
- Stomata are on the lower epidermis
- Mesophyll is differentiatiated into spong and palisade
40
Q
What is Abscission and Where does it occur on a plant?
A
- Plants whose leaves drop periodically are called deciduous plants
- The process of leaf shedding = abscission
- An abscission zone develops at the base of the petiole with the formation of a protective layer separation layer
- wind knocks off the leaf and a leaf scar is formed
41
Q
What is the difference between primary and lateral roots?
A
- Primary roots - the first of the vegetative organs to emergy from the germinating seed
- Lateral root - growth and development of the root system…off of the primary root
42
Q
What is the root cap?
A
- thimble like structure composed of rather looseyl arranged parenchyma cells that covers the root apex
- \no equivalent in stems
43
Q
What are the 3 zones to a young root/shoot?
A
- Region of division
- Region of Cell elongation
-
Region of Differentiation
- region of maturation
44
Q
What is the region of division in roots?
A
- compact tissue immediately behind the root cap composed of small cells
- Also called the meristematic region
45
Q
What is the region of elongation in the roots? What are the 3 primary meristems found here?
A
- Protoderm - single layer of cells that will differentiate into the epidermis
-
Ground Meristem - several cell layers thick and extend from protoderm to near the center
- produces cortex and endodermis
-
Procambium - comprised of several cell layer in the central region
- will give rise to the tissues of the stele (vascular tissues)
46
Q
Where is the region of differentiation in roots and what comprises it?
A
- it is also known as the root hair zone and is adjacent to the region of elongation, further up the root
- Root Hairs and other cells take their final form here. Theses are the primary tissues
*
47
Q
Epidermis of the root
A
- derived from the protoderm and consists of a single layer of parenchyma cell
- Normally lack a cuticle
48
Q
Cortex of the root
A
- broad area of parenchyma cells derived from the ground meristem
- located interior to the epidermis and includes the endodermis
49
Q
Endodermis of the Root
A
- single layer of cells characterized by Casparian strip
- Casparian strip refers to an area of cell wall that has been secondarily thickened with lignin and waterproffed with suberin
- Surrounds the stele and regulates which minerals pass from cortex to vascular tissue
50
Q
What is the Pericycle of the root?
A
- Layer of cells just inside the endodermis
- Derived from the procambium
- Lateral roots are created by the pericycle
51
Q
What is primary phloem of the root?
A
- complex tissue derived from the procambium that occurs in strands between the radiating arms of the priary xylem
52
Q
What is the vascular cambium in roots?
A
- consists of undifferentiated procambrial cells between the primary xylem and phloem.
- Appear rectangular
53
Q
What is the primary Xylem of the roots?
A
- Complex tissue derived from the procambium that occupies teh center of the root
54
Q
Is there pith in the roots of angiosperms?
A
- pith region consisting of parenchyma cells is normally in monocot roots
55
Q
What is the stele in roots?
A
- Central part of the root. It includes all tissues inside the cortex
- pericycle
- vascular tissues
- Pith center - in monocots
56
Q
What is the hypodermis in Roots?
A
- the outermost layer or layers of cortex cells
- Can be found in stems and roots
- Helps the plant retain water
