Plant Tissues Flashcards
Tissues
Groups of similar cells joined together for a particular function
Where does cell division take place?
Within meristematic cells
Where are primary meristems found?
At the shoot and root tips
Where are secondary meristems found
Within the stem
Meristem
A zone of active division in plants
Describe a meristematic cell
Thin walled and small and develop into all other cell types
Simple tissue
Only one cell type
Complex tissue
More than one cell type
3 types of plant tissue
Dermal
Vascular
Ground
Dermal tissue
A single layer of cells covering the different parts of the plant
Example of dermal tissue
Epidermis
Vascular tissue
Involved in transport within the plant
2 examples of vascular tissue
Xylem and phloem
Ground tissue
All tissue except dermal and vascular
Is the epidermis living?
Yes
Cuticle of the epidermis
A waxy layer covering the outer surface called the cuticle
Location of the epidermis
Covers the outer surfaces of leaves, stems and roots
Function of dermal tissue
Protection
If cuticle present-prevents water los and entry of fungal parasites eg.mildew
3 vascular tissues
Xylem vessels, tracheids and phloem
How are xylem vessels formed
Tubes formed when the end walls of cells break down
Appearance of xylem vessels
Tubes extending from roots to leaves
Are xylem vessels living
No they are dead at maturity
What gives xylem vessels great strength
They have thick lignificad walls
Lingin
A chemical substance harder than cellulose
Why do xylem vessels have pits?
Allow water to pass through
What forms wood
Lignified xylem
Location of xylem vessels
In vascular bundles of stems, roots and leaves and in wood
2 functions of xylem vessels
Transport water and minerals up through plant
Strength and support
Appearance of xylem tracheids
Elongated cells pointed at both ends
How can water pass from one tracheid to another
Through the pits in their walls
Are tracheids living?
No
Tracheid cell walls are
Lignified
What’s different about tracheids 2 to vessels
Primitive cells
Found in coniferous trees egpine
Location of tracheids
In vascular bundles of stems, roots and leaves and in wood
2 functions of tracheids
Transport of water and minerals up through the plant
Strength and support
2 cell types in phloem
Sieve tubes and companion cells
Appearance of phloem sieve tubes
Tubes of cells extending from roots to leaves
How are sieve tubes formed
Unlike xylem, walls don’t break down but they become perforated with pores to become sieve plates
Nuclei disappear but cytoplasm remains and is seen to stream through the pores in the sieve plates
Cell walls of phloem
Thin
Made of cellulose
No lingin
Where are companion cells in phloem
They lie close to each sieve tube cell
Are sieve tubes living
No
Are companion cells living
Yes
Is phloem a living tissue
Yes
Location of phloem
In the vascular bundles of stems, roots and leaves and in bark
Function of sieve tubes
Movement of food and other organic substances eg. Hormones around the plant
Translocation ^^
Companion cell function
Control the functioning of the sieve tubes
organs
Composed of a number of different tissues working together to perform a function (s)
Example of plant organ
Leaf
