Biology Questions and Answers
(phelloderm, phellogen and cork) as in
dicots and gymnosperms.
The leaves are covered by epidermis.
- What is phellogen? What
is its function?
Phellogen, also known as cork cambium,
is the meristematicresponsible for the formation o plant tissuef the (^)
periderm (the covering of the stem,
shoots and roots). Thphellogen layer forms the phelloderme inner side of the
and its outer side forms the cork
(suber). The suber secretes simpermeable substance that uberin, an
impregnates the tissue.
- Which type of plant tissue
is cork?
Cork, the material, for example, used to
cap wine bottles, is extracted suber of a special oak called cork ofrom theak.
- What are the plant root
hairs? Where can they be
found and what is their
function?
The root hairs are external projections of the root epidermis. Theirelongated (^)
role is to iwater by the root.ncrease the absorption of
- Why does bark often die
and break naturally?
The bark is the mature periderm of thestem, bbreaks wranches and roots. It dies andhen these structures grow and (^)
thus the peridermal suber formed of
already dead cells ruptures.
- What is the leaf cuticle?
The leaf cuticle is a thin waxy laymade of cutin and waxes on the outerer (^)
surface of the leaf epidermis. Itsfunction is to control the cellular
transpiration.
- Which are the plant
tissues that form the plant
roots?
The roots havmedulla made of vasculare a central portion called tissue (inner (^)
xylem is surrounded by the medullaryand outer phloem). The medulla
parenchyma and delimited by pericycle,
a meristem that orisecondary roots (ramifications).ginates the (^)
Externally to thcortical portion e medulla lies theformed of endodermis (^)
(that surrounds the pericycle) and
corticalthe roots is epidermis (with r parenchyma. The coverinoot hairs)g of (^)
later substituted by suberized (corky)
periderm.
- What is the root cap?
The root cap located in the tip of the growing root. Itis a protective structure (^)
protectsroot forming a cap that surr the meristematic tissue oounds thef the
tip. The cover is necessary since during
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