Easyanswers.blog.com

Plant tissues are of two kinds.Thay are (1)Simple tissues (2)Complex tissues The complex tissues help in transportation of substances in higher plants.In lower plants,transportation takes place by Diffusion,Osmosis and by active transport.         But in higher plants,transportation is done by vascular tissues as substances have to travel long distances.This type of movement of substances by conducting tissues is called Translocation Complex tissues Complex tissues is also called as Vascular tissues or Secondary tissues or Conducting tissues. Complex tissues are of two types.They are: (1)xylem (2)Phloem   Xylem: Xylem is a thick-walled,tubular,placed end to end like pipelines.It conducts water and minerals from roots to stems and leaves.It is uni-directional i.e.upward direction.It provides mechanical strength to the plant.It consists of : Trachieds,Vessels,xylem fibres and xylem parenchyma. Gymnosperms lack vessels.So presence of...

Organelle or cell organelle Besides the cell wall and cell membrane, there is an another membrane bound structure is called organelles.cytoplasm forms the entire living structure which is present inside the cell membrane.when we observe the cell under the electron microscope, the cytoplasm consists of many tiny structures which are called as Organelles. As we have  different organs in our body,likewise there are different organelles inside the cell.Different organelles have their respective functions. The main organelles which are found in cytoplasm of cell are: Endoplasmic reticulum Ribosomes Mitochondria Golgi bodies Lysosomes Centrosomes(found only in animal cells) Plastids(found only in plant cells) Vacoules Lysosomes.

Cell wall Cell wall is the outermost layer of cell.It is made up of mainly by cellulose other components may also forms cell wall in addition with cellulose in different organisms.It is a non-living structure.It provides shape to the cell and gives rigidity to form the outer covering.It has many functions.It protects the cell and its constituents against mechanical injuries such as damage and infection.Protects the cell from disease causing agents.It allows the substances to enter and leave the cell.It helps in the interaction of one cell to another cell mainly by calcium pectate which is middle lamella.cell wall is a characteristic feature in plants.It is also present in prokaryotes like monerans and also present in some eukaryotes except Animalia.Cell wall is absent in Animals. Cell membrane It is the layer next to the cell wall.Also called as plasma membrane.It is a living structure and very thin,delicate and flexible.Its function is to allow certain substances(not all s...