Plant Tissues Flashcards
group of cells of the same type or of the mixed type, having a common origin and performing an identical function.
plant tissues
may be classified into two groups: meristematic tissue
and permanent tissue.
plant tissues
have cells which are
continuously dividing.
meristematic tissue
found in the growing regions
of the plant (apices of roots
and shoot)
meristematic tissue
cells are immature and are capable of undergoing repeated division throughout their life.
meristematic tissue
types of meristematic tissue
Based on origin, Based on the location, Based on function
based on origin
- Promeristem
- Primary meristem
- Secondary meristem
based on location
- Apical meristem
- Intercalary meristem
- Lateral meristem
based on function
- Protoderm
- Procambium
- Ground meristem
- 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
found in the tips of root and shoot
apical meristem
found in the internodes or at the base of the leaves
intercalary meristem
found in the lateral surface of the stem and the root
lateral meristem
- 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
- Parenhcyma
- Collenchyma
- Sclerenchyma
Complex tissue
- Xylem
- Phloem
covers the plant and can be found on the outer layer of roots, stems and leaves
dermal tissue
functions are transpiration, gas exchange and defense.
dermal tissue
epidermis and periderm
dermal tissue
In woody plants, the _____ breaks apart into a thick periderm as secondary growth allows the plant to grow in girth.
epidermis
functions as the first line of defense for the plant, protecting it from fire or heat injury, dehydration, freezing conditions, and/or disease.
periderm
perform photosynthesis, storage and secretion
parenchyma
provide mechanical support
collenchyma
usually dead or without protoplast
sclerenchyma
chlorenchyma and aerenchyma
parenchyma
parenchymatous tissue that contains chloroplasts and chlorophyll
chlorenchyma
parenchyma tissue with large air spaces between cells.
aerenchyma
▪ help support young parts of
the plant shoot.
Collenchyma
▪ elongated cells that have thicker primary walls
Collenchyma
▪ provide 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.
Sclerenchyma
▪ contains large amounts of lignin, a relatively indigestible
strengthening polymer that accounts for more than a quarter of the dry mass of wood
Sclerenchyma
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
▪ has two types: fiber and sclereids
Sclerenchyma
made up of pure cellulose
fiber
xylem and phloem
vascular tissue
Performs conduction of water and mineral salts from the roots to the top of plants
xylem
transport of food products from green parts to the storage organs and to other organs of plants
phloem
