Class 9 Biology: Plant Tissues and Anatomy

Vocabulary flashcards defining key structural concepts, cellular components, vascular systems, and protective tissues based on Class 9 plant tissue notes.

Tissue

A group of cells that are similar in structure and origin, working together to perform a specific common function.

Bichat

The scientist who coined the term tissue.

Anatomy

The study of the internal structure of any part of an organism with the help of section cutting.

Histology

The study of tissues with the help of a microscope.

Division of Labour

The specialization where cells develop specific shapes, sizes, and structures to carry out distinct physiological functions in multicellular organisms.

Meristematic Tissue

Plant tissue composed of small, undifferentiated cells capable of continuous division that lack vacuoles and have high metabolic rates.

Permanent Tissue

Plant tissue composed of differentiated cells that have lost the capacity to divide and are specialized for functions like protection, storage, and transportation.

Simple Tissue

Plant permanent tissue composed of a single type of cell that serves protective and supportive functions.

Complex Tissue

Plant permanent tissue composed of more than one type of cell working together to perform conductive functions.

Xylem

A complex vascular tissue made of vessels, tracheids, xylem parenchyma, and xylem fibres that conducts water and minerals unidirectionally from roots to leaves.

Phloem

A complex vascular tissue made of sieve tubes, companion cells, phloem parenchyma, and phloem fibres that translocates food bidirectionally from leaves to other plant parts.

Lignin

A substance that stiffens cell walls and makes them impermeable, resulting in the cells becoming dead.

Sclereids

A type of sclerenchyma cell present in the pulp of pear fruit that produces a special sound upon eating.

Companion Cells

Specialized living cells adjacent to sieve tube elements that share a common meristematic origin and allow nuclear control over nucleated-lacking sieve tubes.

Epidermis

The outermost layer of parenchymal cells covering plant organs, protecting internal tissues from mechanical injuries and invasion by pathogens.

Cuticle

A waterproof outer layer formed by the waxy substance cutin deposited on the outer epidermal walls of aerial plant parts.

Guard Cells

Two kidney-shaped chloroplast-containing epidermal cells that surround each stoma to regulate its opening and closing.

Transpiration

The loss of water in the form of water vapor taking place through the stomata of leaves.

Epiblema

The epidermal layer of roots that features root hairs to greatly increase the surface area for absorption of water and minerals.

Cork (Phellem)

Peripheral dead protective tissue of old stems and roots formed on the outer side by the activity of phellogen.

Phellogen

The secondary lateral meristem (cork cambium) that forms phellem (cork) on its outer side and phelloderm on its inner side.

Phelloderm

The secondary cortex tissue formed on the inner side by the activity of cork cambium (phellogen).

Quercus suber

The cork oak species from whose stem surface commercial cork is obtained.

Dedifferentiation

The process in which specialized permanent cells regain the power of division and become meristematic again.