Notes On Eukaryotic Cells - CBSE Class 11 Biology
The cells that possess an organised nucleus surrounded by a nuclear envelope are called eukaryotic cells. The nucleus contains chromosomes that carry the genetic code of the organism. The cytoplasm contains a network of filamentous structures called cytoskeleton, which gives the cell its shape, strength and also aids in intracellular transport. The cytoplasm of all eukaryotic cells contains membrane bound organelles, but they may vary from cell to cell. For instance, plant cells have a large central vacuole and plastids whereas centrosomes are found only in animal cells.

Eukaryotic cells differ not only in their cytoplasmic organelles but also in their structure.
The composition of the cell wall is different in different eukaryotic cells. In algae, the cell wall is made of cellulose, mannans, galactans and calcium carbonate whereas in fungi, it is made of chitin and glucans. On the other hand, a plant cell wall is made of cellulose, hemicellulose, pectins and proteins and consists of three layers.

The middle lamella, glues the cells together, the primary wall develops when the cell is growing and the secondary wall faces the plasma membrane. The cell wall is interrupted by plasmodesmata, which are fine strands of cytoplasm that facilitate the transportation of materials between different cells. The cell wall lends shape to the cell, protects it from mechanical damage and infection, prevents the entry of undesirable macromolecules and also aids in cell-to-cell interaction. 

Summary

The cells that possess an organised nucleus surrounded by a nuclear envelope are called eukaryotic cells. The nucleus contains chromosomes that carry the genetic code of the organism. The cytoplasm contains a network of filamentous structures called cytoskeleton, which gives the cell its shape, strength and also aids in intracellular transport. The cytoplasm of all eukaryotic cells contains membrane bound organelles, but they may vary from cell to cell. For instance, plant cells have a large central vacuole and plastids whereas centrosomes are found only in animal cells.

Eukaryotic cells differ not only in their cytoplasmic organelles but also in their structure.
The composition of the cell wall is different in different eukaryotic cells. In algae, the cell wall is made of cellulose, mannans, galactans and calcium carbonate whereas in fungi, it is made of chitin and glucans. On the other hand, a plant cell wall is made of cellulose, hemicellulose, pectins and proteins and consists of three layers.

The middle lamella, glues the cells together, the primary wall develops when the cell is growing and the secondary wall faces the plasma membrane. The cell wall is interrupted by plasmodesmata, which are fine strands of cytoplasm that facilitate the transportation of materials between different cells. The cell wall lends shape to the cell, protects it from mechanical damage and infection, prevents the entry of undesirable macromolecules and also aids in cell-to-cell interaction. 

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