Activity 5: Plant Histology Flashcards
(41 cards)
an aggregation of cells of a common source, structure, and function in intimate union.
tissue
found at the tip of roots and shoots, which produce new cells to increase the length of the root or shoot.
apical meristem
tend to have large vacuoles and may contain various secretions.
classified as either aerenchyma cells, which have extensively connected air spaces, and chlorenchyma cells, which contain chloroplasts or green pigments.
parenchyma cells
somewhat elongated cells; that provide excellent support and strengthening functions being located just beneath the epidermis and thickened at the corners.
collenchyma cells
support and protect due to the shape, thickness, and toughness of their cell walls, which are deposited with lignin.
further classified as sclereids (isodiametric cells) and fibers, which are elongated cells with pointed ends.
sclerenchyma cells
primary conducting tissue for water and absorbed minerals from the soil.
The phloem is the primary conducting tissue for food manufactured from leaves.
Some plants contain fiber, which are elongated cells with tapering ends.
xylem
made up of tracheids, which are tubes that taper at the end, with pits that allow passage of water between cells and rays, which are essential for lateral short-distance conduction.
tracheary tissue
flattened, thin-walled cells with little or no intercellular spaces.
These make up the periderm that constitutes the outer bark of a woody stem.
cork cells
single layer of compactly arranged cells surrounding the vascular tissue core of roots.
It is composed of parenchyma cells with thickening on the radial side and end walls of cells forming a waterproof band called Casparian Strip.
endodermis
- also known as embryonic tissue.
- undifferentiated tissue composed of cells in the state of active division.
- found in the growing apices of roots, stems, and leaves.
meristematic tissues
The meristem in the stems, roots, and leaves is the _______________.
The meristem found in the cambium, cork cambium, and pericambium is the ______________.
primary meristem
secondary meristem
meristematic tissues are further divided into three other regions:
apical meristem
lateral meristem
intercalary meristem
responsible for primary growth
apical meristem
responsible for secondary growth
lateral meristem
responsible for tissues that do not have a vascular or cork cambium
intercalary meristem
The _______ growth increases the length of the plant. It is what makes the plant tall, while _________ growth increases the girth or the diameter of the plants.
primary
secondary
- tissues that are composed of more mature and differentiated tissues.
- usually found in stems, roots, and barks
- further divided into other types of tissues.
parenchyma tissue
aerenchyma and chlorenchyma and transfer cells
Cellular Profile of Parenchyma tissues:
- Actively dividing
- Mostly rounded cells but may occur in other shapes
- Cells have thin and pliable cell walls
- Cells are loosely packed
- usually found underneath the epidermis
- Aside from providing strength, they also provide flexibility to young plants, leaves, and floral parts.
collenchyma
Cellular Profile of Collenchyma tissues:
- Cells are prismatic
- Have thickened cell walls
- Filled with colloidal substance
- contains lignified cells.
- makes them ideal for making textile products and linens
2 types
sclerenchyma
stone cells and fiber cells
are cells that are irregularly shaped.
Stone Cells (Sclereids)
- contain a lumen.
- tough and flexible.
fiber cells
- single layer of compactly arranged cells surrounding the vascular tissue core of roots.
- composed of parenchyma cells with thickening on the radial side and end wall of the cells forming a waterproof band called Casparian Strip.
- made up of lignin (cementing material between cells related to cellulose) and suberin (a fatty substance that makes the cell wall waterproof).
endodermis