What are three main differences between plant and animal cells?
Major structural differences between a plant and an animal cell include:
- Plant cells have a cell wall, but animals cells do not.
- Plant cells have chloroplasts, but animal cells do not.
- Plant cells usually have one or more large vacuole(s), while animal cells have smaller vacuoles, if any are present.
What is a simple permanent tissue?
Simple permanent tissues are composed of cells which are structurally and functionally similar. These tissues are made up of one type of cells. A few layers of cells beneath the epidermis are generally simple permanent tissue.
Why Sclerenchyma is called dead cells?
Sclerenchyma is called a dead tissue because the cells have thick lignified secondary walls, which often die when they are matured and have ceased their elongation.
What is the main function of Sclerenchyma cells in the plant body?
Sclerenchyma cells are strong, thick cells that provide most of the support in a plant. They are known to have extremely thick cell walls and do not participate in many of the other activities of the developing plant, such as photosynthesis, because their focus is strictly on support and structure.
How do you identify Sclerenchyma?
Cells of sclerenchyma tissue are higly lignified with very thick cell walls and obliterated lumen. Cells are usually elongated and polygonal in shape in cross-section. The tissue provides the mechanical support and is found below the epidermis and around the vascular bundles.
Where is Sclerenchyma found?
They are found mainly in the cortex of stems and in leaves. The major function of sclerenchyma is support. Unlike collenchyma, mature cells of this tissue are generally dead and have thick walls containing lignin. Their size, shape, and structure vary greatly.
What is Sclerenchyma Class 9?
Sclerenchyma cells are elongated, dead cells with lignin deposits in their cell wall. They have no intercellular gaps. Sclerenchyma provides strength to the plant. The main function of sclerenchyma is to provide mechanical support and protection to the plant.
What is lignin in biology class 9?
Lignin is a chemically complex substance found in many plants, which bonds the cellulose fibers. It forms the woody cell walls of plants and the “cement” between them. Lignin is found together with cellulose and is resistant to biological decomposition. Lignin is the chief constituent of wood other than carbohydrates.