General Biology : Sir Nico's Materials Plant Tissue Flashcards
▪ group of cells of the same type or of the mixed type,
having a common origin and performing an identical
function.
▪ may be classified into two groups: meristematic tissue
and permanent tissue.
Plant Tissue
▪ have cells which are
continuously dividing.
▪ found in the growing regions
of the plant (apices of roots
and shoot)
▪ cells are immature and are
capable of undergoing repeated division throughout their life.
Meristematic Tissue
Meristematic Tissue: Based on Origin
- Promeristem
- Primary meristem
- Secondary meristem
PPS
Podrigo Puterte Supporter
Meristematic Tissue: Based on Location
- Apical
meristem - Intercalary
meristem - Lateral
meristem
A.I.L.
Meristematic Tissue: Based on
function
- Protoderm
- Procambium
- Ground
meristem
PPG
- youngest stage of the
growing organ - gives rise to primary
meristem
Promeristem
- Embryonic tissues
-gives rise epidermis, the
cortex, the leaves and the pith.
Primary Meristem
-It develops later from non
-meristematic tissues at a
certain stage of
development of an organ of
a plant.
Secondary Meristem
The area of actively dividing cells that locates at the tips of the roots and the shoots.
Aids increase of height of the plant by facilitating the growth of the shoot and the root.
Apical Meristem (top)
The area of actively dividing cells that locates at the internodes.
Contributes to the increase in height, with the growth of internodes.
Intercalary Meristem (Mid)
The area of actively dividing cells that allocates at the lateral side of the stem and the root.
Increases the thickness of the plant by increasing the diameter of the plant.
Lateral Meristem (Bottom)
- outermost plant tissue and
forms the epidermis - located around the outside of the stem
and protects the plants from any
mechanical shocks.
Protoderm
innermost tissue and
gives rise to the xylem and phloem.
procambium
-cells are large with
thick walls.
-gives rise to ground tissue
Ground Meristem
composed of cells that
have lost the power of
division, having attained
their definite form and
sizes (differentiated and
mature).
Permanent Tissue
Simple Permanent
-Parenchyma
-Collenchyma
-Sclerenchyma
Complex Tissue
-Xylem
-Phloem
Permanent Tissue
- Dermal
- Vascular
- Ground
▪ covers the plant (found on the outer layer of roots, stems and leaves)
▪ transpiration, gas exchange and defense.
▪ woody plants > epidermis breaks apart into a thick periderm > secondary growth > grow in girth.
▪ protecting it from fire or heat injury, dehydration, freezing
conditions, and/or disease.
▪ first line of defense
Dermal Tissue
- Isodiametric Cells
- Varied Shapes
- Made of Cellulose (thin walls)
- Photosynthesis, storage, secretion
- chloroplast / chlorophyll
- closely packed / intercellular space
Parenchyma
Parenchyma
Chlorenchyma, Aerenchyma
parenchymatous tissue that contains chloroplasts and
chlorophyll
Chlorenchyma
parenchyma tissue with large air spaces between cells.
Aerenchyma
- layer below epidermis
- photosynthesis if chloroplast are present
- hamogeneous or in patches
- thickened w/ cellulose, hemicellulose or pectin
- no intercellular space
▪ help support young parts of
the plant shoot.
▪ elongated cells that have
thicker primary walls
▪ flexible support without restraining growth. - At maturity, these cells are
living and flexible, elongating
with the stems and leaves
they support
Collenchyma
▪ supporting elements in the
plant but are much more
rigid than collenchyma cells.
▪ contains large amounts of
lignin, a relatively indigestible
strengthening polymer that
accounts for more than a
quarter of the dry mass of
wood
▪ has two types: fiber and
sclereids
Sclerenchyma
Two Types of Schlerenchyma
Fiber, Sclereids
Two Types of Schlerenchyma: Made up of Cellulose
Fiber
Two Types of Schlerenchyma: may occur in the cortex, pith, phloem, hard seeds, nuts, stony
fruits, in leaves and in the stems of many plants. They are also known as grit cells
Sclereids
- Waters and Minerals
- One-way flow of sap
- thick cell wall of lignin
- cells having no ends wall between them
Xylem
- water and food
- two-way flow of sap
- thin cell wall made of cellulose
- cells with ends walls and perforations
Phloem
Xylem : Performs conduction of water and mineral salts from the roots to the top of plants
tracheids, vessels
Xylem:
▪ long and tapered ends
▪ main function is to conduct
water; and provide
mechanical support
Tracheids
Xylem:
▪ wider, shorter, thinner walled,
less tapered, aligned end to
end, perforation plates, walls
lignified
▪ have perforation plates that
enable water to flow freely
through the vessels.
Vessels
also called as bast or lepton
Phloem
Phloem
- Sieve tube elementt
- Companion Cells
▪ name sieve derives from the strainer appearance given to the cells by the presence
of numerous pores crossing their bodies.
▪ used for the longitudinal transmission of food
▪ general term for sieve cells and sieve tube element
Sieve Elements
Phloem:
▪ lack a nucleus, ribosomes, a distinct vacuole,
and cytoskeletal elements
▪ Has sieve plates
Sieve Tube Elements
Phloem:
▪ connected to the sieve-tube element by
numerous plasmodesmata
▪ help load sugars into the sieve-tube elements,
which then transport the sugars to other parts of
the plant.
Companion Cells
