EUKARYOTIC CELLS

The eukaryotes include all the protists, plants, animals and fungi. In eukaryotic cells there is an extensive compartmentalisation of cytoplasm through the presence of membrane bound organelles. Eukaryotic cells possess an organised nucleus with a nuclear envelope. In addition, eukaryotic cells have a variety of complex locomotory and cytoskeletal structures.

Their genetic material is organised into chromosomes. All eukaryotic cells are not identical. Plant and animal cells are different as the former possess cell walls, plastids and a large central vacuole which are absent in animal cells. On the other hand, animal cells have centrioles which are absent in almost all plant cells (Figure .

). Rough endoplasmic reticulum Lysosome Smooth endoplasmic reticulum Plasmodesmata Microtubule Nucleus Nucleolus Golgi apparatus Nuclear envelope Vacuole Middle lamella Plasma membrane Cell wall Mitochondrion Ribosomes Chloroplast Cytoplasm Peroxisome Figure . Diagram showing : (a) Plant cell (b) Animal cell Golgi apparatus Smooth endoplasmic reticulum Nuclear envelope Nucleolus Nucleus Microvilli Plasma membrane Centriole Peroxiome Lysosome Ribosomes Mitochondrion Rough endoplasmic reticulum Cytoplasm (a) (b) Cholesterol Sugar Peripheral Protein Phospholipid bilayer Let us now look at individual cell organelles to understand their structure and functions.