Cell Structure and Function

Cell Structure and Function

Some of the cells have a simple structure and some are complex, but all cells essentially contain three basic parts. They are:

• Cell envelop that contains: Cell membrane: It protects cell content and controls exit and entry of materials from the cell.
• Cell wall: It helps plants to withstand changes in the outside environment without bursting
• Nucleus: It is the control center of a cell.
• It contains chromosomes made up of DNA and protein.
• It contains functional segments of DNA called genes, which are responsible for the transmission of hereditary characters.
• The nucleolus is seen inside the nucleus.
• The nuclear membrane has pores for the exchange of material with the cytoplasm.
• Cytoplasm: It is the fluid content present inside the plasma membrane.
• Protoplasm + Cell organelles = Cytoplasm

• In multicellular organisms, each organ system is made up of several organs.
• Organs are further made up of tissues.
• Tissues are groups of similar cells performing a specific function.
• The number of cells Organisms made up of only a single cell are called unicellular organisms. For example Amoeba and Paramecium
• Single-cell in unicellular organisms performs all the basic functions such as digestion, respiration, and excretion.
• Organisms made up of more than one cell are called multicellular organisms. For example Humans, cows, etc.
• In multicellular organisms, the cells show division of labor as a particular set of cells is involved in performing a specific body function.
• In a unicellular organism, a single cell performs all the basic functions of life but in multicellular organisms, there is a division of labor.