Practical #2 - Plant Form and Function Flashcards
(56 cards)
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
What are **Tracheids and Vessel Elements**
* 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
What is the Interfascicular Cambium
* 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
Where does secondary xylem and phloem originate from?
* 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
Where does the cork cambium originate from?
* **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
Secondary Growth: Eudicots vs Monocots
* Eudictos typically have true secondary growth with vascular cambium, cork cambium, and bark
* Monocots usually dont have secondary growth
30
Describe the difference between Spring Wood and Summer Wood
* 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
Describe the process of Secondary growth in Stems.
* 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
Rays are located in the Xlyem, what do they do?
* Allow the lateral conduction of water and nutrients across the stem
33
What is the difference between heartwood and sapwood
* **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
Diferrent Types of Stems
* **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
Describe Leaf Venation
* The arrangement of **veins,** composed of vascular tissues like phloem and xylem, in the blade is called venation
* 2 types:
* Net-like
* Parallel
36
What is the mesophyll?
* the phtotsynthetic parenchyma between the upper and lower epidermis of the blade
37
What is Palisdae mesophyll (Eudicots)?
* (Palisade parenchyma)
* one or more layer of elongated photosynthetic parenchyma cells lie adjacent to the upper epidermis
38
What is Spongy mesophyll (Eudictos)?
* (Spongy parenchyma)
* Loosely organized photosynthetic parenchyma cells between the palisade mesophyll and the lower epidermis
39
Differences between Monocot Leaves and Eudicot Leaves
* 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
What is Abscission and Where does it occur on a plant?
* 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
What is the difference between primary and lateral roots?
* **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
What is the root cap?
* thimble like structure composed of rather looseyl arranged parenchyma cells that covers the root apex
* \no equivalent in stems
43
What are the 3 zones to a young root/shoot?
* **Region of division**
* **Region of Cell elongation**
* **Region of Differentiation**
* **region of maturation**
44
What is the region of division in roots?
* compact tissue immediately behind the root cap composed of small cells
* Also called the meristematic region
45
What is the region of elongation in the roots? What are the 3 primary meristems found here?
* **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
Where is the region of differentiation in roots and what comprises it?
* 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
Epidermis of the root
* derived from the protoderm and consists of a single layer of parenchyma cell
* Normally lack a cuticle
48
Cortex of the root
* broad area of parenchyma cells derived from the ground meristem
* located interior to the epidermis and includes the endodermis
49
Endodermis of the Root
* 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
What is the Pericycle of the root?
* Layer of cells just inside the endodermis
* Derived from the procambium
* Lateral roots are created by the pericycle
51
What is primary phloem of the root?
* complex tissue derived from the procambium that occurs in strands between the radiating arms of the priary xylem
52
What is the vascular cambium in roots?
* consists of undifferentiated procambrial cells between the primary xylem and phloem.
* Appear rectangular
53
What is the primary Xylem of the roots?
* Complex tissue derived from the procambium that occupies teh center of the root
54
Is there pith in the roots of angiosperms?
* **pith** region consisting of parenchyma cells is normally in monocot roots
55
What is the stele in roots?
* Central part of the root. It includes all tissues inside the cortex
* pericycle
* vascular tissues
* Pith center - in monocots
56
What is the hypodermis in Roots?
* the outermost layer or layers of cortex cells
* Can be found in stems and roots
* Helps the plant retain water
