distinguish between simple tissue and complex tissue. describe the structures and function of three types of simple tissues.
Answers
The complex tissue consists of more than one type of cells which work together as a unit. Complex tissues help in the transportation of organic material, water and minerals up and down the plants. That is why it is also known as conducting and vascular tissue.
Simple Tissue:
1. Simple tissue consists of only one type of tissue, hence is homogeneous.
2. This includes parenchyma, collenchymas and sclernchyma.
3. They occur in all parts of the plant.
4. They perform a wide range of functions.
Complex Tissues:
1. It is composed different types of cells, hence is heterogeneous.
2. This includes xylem and phloem.
3. These have restricted distribution, they occur in vascular region only .
4. These are meant for conduction.
there are three types of simple tissues:
ParenchymaIn parenchymatous tissue all cells are isodiametric and thin walled. The cells may be oval, circular or polygonal with intercellular spaces. They are living. This tissue is present in all organs of the plant e.g., roots, stems, leaves, flowers, fruits and seeds.
CollenchymaCollenchymatous cells are longer than parenchyma cell.. They are living. The intercellular spaces in this tissue are absent because in intercellular spaces at the corner of cells thickenings of cellulose and pectin develop due to which the cell wall become rigid and thick at corners. Sometimes collenchyma develops chloroplasts. Collenchyma is usually found as 3-4 layered hypodermis of herbaceous dicotyledonous stem. They are absent in monocot stems.
SclerenchymaThis tissue differ from previous tissues in possessing thickened secondary walls which may or may not be lignified. They are of various shapes and sizes when mature. They are dead.