with the help of flow chart give brief information about permanent tissues
Answers
Answer:
Explanation:
I. Simple Tissues:
Simple tissues are homogenous and composed of structurally and functionally similar cells.
ADVERTISEMENTS:
These are of three types:
Parenchyma, collenchyma and sclerenchyma. (Fig. 3.2 I-III)
(i) Parenchyma cell (ii) Parenchyma cell (iii) Sclerenchyma(i) Parenchyma:
Parenchyma is the most common tissue which is morphologically and physiologically simple and unspecialized. These cells are found in epidermis, cortex, pericycle, pith etc. They are responsible for photosynthesis, storage of food, secretion etc.
(ii) Collenchyma:
Collenchyma are living tissues composed of more or less elongated cells and often have some chloroplast to carry on photosynthesis. It is generally situated below the epidermis.
(iii) Sclerenchyma:
Cells are long, thick-walled and lignified with tapering ends. These are fibre like in appearance and also known as sclerenchymatous fibre. These are dead cells and perform mechanical function.
II. Complex Tissues:
The complex tissues are composed of different types of cells performing diverse functions. These are of two types xylem and phloem.
ADVERTISEMENTS:
(i) Xylem:
Structurally, xylem consists of both living and nonliving cells. Xylem consist of four elements: tracheids, vessels, xylem fibers and xylem parenchyma (Fig. 3.3).
(i) Xylem
Tracheids:
ADVERTISEMENTS:
Tracheids are elongated or tube-like dead cell with hard, thick and lignified walls. Their ends are tapering, blunt or chisel-like. Their function is conduction of water and providing mechanical support to the plant.
Vessels:
Vessel is long cylindrical, tube like structure with lignified walls and a wide central lumen. The cells are dead as these do not have protoplast. The cells are arranged in longitudinal series in which the partitioned walls (transverse walls) are perforated, so the entire structure looks-like a water pipe. Their main function is transport of water and minerals. It also provides mechanical strength.
Xylem fibers:
ADVERTISEMENTS:
These cells are elongated, lignified and pointed at both the ends. A xylem fiber helps in conduction of water and nutrients from root to the leaf and provides mechanical support to the plant.
Xylem Parenchyma:
The cells are living and thin walled. The main function of xylem parenchyma is to store starch and fatty substances.
(ii) Phloem:
Phloem consists of four types of elements – sieve tubes, companion cells, and phloem parenchyma and phloem fibers (Fig. 3.3 (ii).
Structure of phloem T.S of a postion of phloem
Explanation:
Answer:
Explanation:
I. Simple Tissues:
Simple tissues are homogenous and composed of structurally and functionally similar cells.
ADVERTISEMENTS:
These are of three types:
Parenchyma, collenchyma and sclerenchyma. (Fig. 3.2 I-III)
(i) Parenchyma cell (ii) Parenchyma cell (iii) Sclerenchyma(i) Parenchyma:
Parenchyma is the most common tissue which is morphologically and physiologically simple and unspecialized. These cells are found in epidermis, cortex, pericycle, pith etc. They are responsible for photosynthesis, storage of food, secretion etc.
(ii) Collenchyma:
Collenchyma are living tissues composed of more or less elongated cells and often have some chloroplast to carry on photosynthesis. It is generally situated below the epidermis.
(iii) Sclerenchyma:
Cells are long, thick-walled and lignified with tapering ends. These are fibre like in appearance and also known as sclerenchymatous fibre. These are dead cells and perform mechanical function.
II. Complex Tissues:
The complex tissues are composed of different types of cells performing diverse functions. These are of two types xylem and phloem.
ADVERTISEMENTS:
(i) Xylem:
Structurally, xylem consists of both living and nonliving cells. Xylem consist of four elements: tracheids, vessels, xylem fibers and xylem parenchyma (Fig. 3.3).
(i) Xylem
Tracheids:
ADVERTISEMENTS:
Tracheids are elongated or tube-like dead cell with hard, thick and lignified walls. Their ends are tapering, blunt or chisel-like. Their function is conduction of water and providing mechanical support to the plant.
Vessels:
Vessel is long cylindrical, tube like structure with lignified walls and a wide central lumen. The cells are dead as these do not have protoplast. The cells are arranged in longitudinal series in which the partitioned walls (transverse walls) are perforated, so the entire structure looks-like a water pipe. Their main function is transport of water and minerals. It also provides mechanical strength.
Xylem fibers:
ADVERTISEMENTS:
These cells are elongated, lignified and pointed at both the ends. A xylem fiber helps in conduction of water and nutrients from root to the leaf and provides mechanical support to the plant.
Xylem Parenchyma:
The cells are living and thin walled. The main function of xylem parenchyma is to store starch and fatty substances.
(ii) Phloem:
Phloem consists of four types of elements – sieve tubes, companion cells, and phloem parenchyma and phloem fibers (Fig. 3.3 (ii).
Structure of phloem T.S of a postion of phloem