Functions of Golgi bodies:
1. Glycoproteins and glycolipids are produced.
2. Transporting and storing lipids.
3. Formation of lysosomes.
4. Production of digestive enzymes.
5. Cell plate and cell wall formation.
6. Secretion of Carbohydrates for the formation of plant cell walls and insect cuticles.
7. Zymogen granules (proenzyme/precursor of all enzyme) are synthesised.

The cell wall plays a vital role in holding several important functions given below
1. Offers definite shape and rigidity to the cell.
2. Serves as barrier for several molecules to enter the cells.
3. Provides protection to the internal protoplasm against mechanical injury.
4. Prevents the bursting of cells by maintaining the osmotic pressure.
5. Plays a major role by acting as a mechanism of defense for the cells.

1. Glyoxysome is a single membrane bound organelle.
2. It is a sub cellular organelle and contains enzymes of glyoxylate pathway.
3. β-oxidation of fatty acid occurs in glyoxysomes of germinating seeds Eg: Castor seeds.

1. Peroxisomes are small spherical bodies and single membrane bound organelle.
2. It takes part in photorespiration and associated with glycolate metabolism. In plants, leaf cells have many peroxisomes.

1. Photosynthesis.
2. Light reactions takes place in granum.
3. Dark reactions take place in stroma.
4. Chloroplast is involved in photorespiration.

The largest of the internal membranes is called the Endoplasmic Reticulum (ER). The name endoplasmic reticulum was given by K R. Porter (1948). It consists of double membrane. Morphologically the structure of endoplasmic reticulum consists of:
1.Cisternae are long, broad, flat, sac-like structures arranged in parallel bundles or stacks to form lamella. The space between membranes of cisternae is filled with fluid.
2.Vesicles are oval membrane bound vacuolar structure.

3.Tubules are irregular shaped, branched, smooth walled, enclosing a space.
(i) Endoplasmic reticulum is associated with nuclear membrane and cell surface membrane.
(ii) It forms a network in cytoplasm and gives mechanical support to the cell. Its chemical environment enables protein folding and undergo modification necessary for their function.
(iii) Misfolded proteins are pulled out and are degraded in endoplasmic reticulum. When ribosomes are present in the outer surface of the membrane it is called as Rough Endoplasmic Reticulum(RER), when the ribosomes are absent in the endoplasmic reticulum it is called as Smooth Endoplasmic Reticulum(SER).
(iv) Rough Endoplasmic reticulum is involved in protein synthesis and Smooth Endoplasmic reticulum are the sites of lipid synthesis.
(v) The smooth endoplasmic reticulum contains enzymes that detoxify lipid soluble drugs, certain chemicals and other harmful compounds.

Cell wall is the outermost protective cover of cell. It was first observed by Robert Hooke. In plants it is made up of cellulose, hemicellulose, pectin, lignin, cutin. suberin and silica. In a plant cell wall shows J three distinct regions (a) Primary wall (b) Secondary wall (c) Middle lamellae
(a) Primary wall:
(i) It is the first layer inner to middle lamellae, primarily consisting of loose network of cellulose microfibrils in a gel matrix.
(ii) It is thin, elastic and extensible. In most plants the microfibrils are made up of cellulose oriented differently based on shape and thickness of the wall.
(iii) The matrix of the primary wall is composed of hemicellulose, pectin, glycoprotein and water.
(iv) Hemicellulose binds the microfibrils with matrix and glycoproteins control the orientation of microfibrils while pectin serves as filling material of the matrix.
(v) Cells such as parenchyma and meristems have only primary wall.

  Plant Cell Wall
b. Secondary wall :
(i) Secondary wall is laid during maturation. It plays a key role in determining the shape of a cell. It is thick, inelastic and is made up of cellulose and lignin.
(ii) The secondary wall is divided into three sub layers termed as SI' S2 and S3 where the cellulose microfibrils are compactly arranged with different orientation forming a laminated structure and the cell wall strength is increased.
c. Middle lamellae:
(i) It is the outermost layer made up of calcium and magnesium pectate, deposited at the time of cytokinesis.
(ii) It is a thin amorphous layer which cements two adjacent cells. It is optically inactive (isotropic).
(iii) Plasmodesmata and Pits: Plasmodesmata act as a channel between the protoplasm of adjacent cells through which many substances pass through.
(iv) Moreover, at few regions the secondary wall layer is laid unevenly whereas the primary wall and middle lamellae are laid continuously such regions are called pits
(v) The pits of adjacent cells are opposite to each other. Each pit has a pit chamber and a pit membrane.
(vi) The pit membrane has many minute pores and thus they are permeable. The pits are of two types namely simple and bordered pit.

Images of structures observed through microscopes can , be further magnified, projected and saved by attaching a camera to the microscope by a microscope coupler or eyepiece adaptor. Picture taken using aInbullt camera in a microscope is called microphotography or microphotograph.

The microtubules bind all along the mitotic chromosome. Example: Caenorbabditis elegans (transparent nematode) and many insects.

The type of centromere in which the kinetochore is assembled as a result of protein recognition of specific DNA sequences. Kinetochores assembled on point centromere bind a single, microtubule. It is also called as localized centromere. It occurs in budding yeasts.

Chromomeres are bead like accumulations of chromatin material which are visible along interphase chromosomes. They can be seen in polytene chromosomes. At metaphase they are not visible.

The cell inclusions are the non-living materials present in the cytoplasm. They are organic arid inorganic compounds.

Two eukaryotic organelles believed to be the descendants of the endosymbiotic prokaryotes. The ancestors of the eukaryotic cell engulfed a bacterium and the bacteria continued to function inside the host cell.