L12 Plant Physiology: Tissues Flashcards
(23 cards)
What is Meristemic Tissue responsible for?
Growth
Meristemic tissue includes apical and axillary meristem, cork cambium, and lateral meristem.
What is the function of the Apical meristem?
Lengthening (primary growth)
Found at stem and root tips.
What does the Cork cambium do?
Thickening in woody plants
It forms a tube running along the length of roots and stems.
What is the role of Lateral meristem?
Widening (secondary growth)
It forms a tube along roots and stems.
Define Parenchyma.
Unspecialized, abundant, rapidly-dividing, thin-walled cells
They can adapt to various functions through differentiation.
What is Chlorenchyma responsible for?
Photosynthesis
A type of parenchyma tissue.
What function does Collenchyma serve?
Flexible support
Example: celery sticks.
What is the function of Schlerenchyma?
Tough structural support
Includes fibers such as hemp rope.
What is Aerenchyma?
Tissue with pockets of air for gas exchange and flotation
Found in aquatic plants.
What are Complex Tissues composed of?
More than one type of cell
They are involved in water and nutrient transport.
What are the two main types of complex tissues?
Xylem and Phloem
They form the circulatory system of plants.
Where is Xylem located?
Centrally
Found in roots, stems, and leaves.
What does Xylem transport?
Fluid up from the roots
Composed of parenchymal tissue and reinforced with lignin.
What characterizes Phloem?
Located peripherally to the Xylem
Contains large tube-like cells with pores in end sieve plates.
What does Phloem transport?
Glucose from leaves to all cells
Glucose is formed in photosynthesis.
What is sap?
- Watery fluid that circulates through the
- plant.
- Frequently has strong antiseptic properties.
Contains minerals and can have important medicinal properties
True or False: Phloem cells retain their nuclei at maturity.
False
They lose their nuclei and depend on companion cells - hence they are ‘double cells’.
What are protective tubular epidermal cell outgrowths called?
Hairs (trichomas)
Example: hairs on Nettle.
What do Glands in plants do?
Secrete chemicals and remove wastes
Example: holes in the leaves of St John’s Wort.
What is the primary function of the Epidermis?
Protective outer covering
Normally one cell thick, may be thicker to prevent dessication.
What is cutin?
Waterproof waxy substance secreted by epidermal cells
Forms the protective cuticle.
What replaces the epidermis in woody plants?
Periderm
Comprised of cork cells impregnated with suberin.
What are slit-like lenticels?
Structures that allow for gas exchange
They lack suberin.
