Cell structure and itscomponents Cell:Human body is made upof several small units called cells. Cell controls all the activities of all living organisms.The cell was discoveredby the scientist Robert Hooke.The name was taken fromthe Latin;’cellula’ means “a small chamber”.Classificationof cells:Typeof cells:1. Prokaryotic cell.
2. Eukaryotic cell.Prokaryoticcell:A cell that does notcontain membrane-bound organelles is called a prokaryotic cellIt is known as simplecell.
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Example: Bacteria.Eukaryoticcell:A cell that contain awell defined nucleus, a nuclear membrane and membrane-bound cell organelles iscalled a eukaryotic cell It is known as acomplete cell.The two types of Eukaryoticcells are:1. Animal cell.
2. Plant cell.The animal and plantcells are not same.
They vary in theirsize and structure and their functions, but both the cells are similar in theirbasic organisation.Animalcell:Plasma membrane:· It gives rigid structure and shape tothe cell.· It protects the cell.Cytoplasm: · It is a liquid like material inside thecell.· It contain proteins.
Nucleus:· It remotes all the activities of the cell.· It contains the genetic material.Mitochondria:· Mitochondria Involved in the process ofcell respiration.· It Provide energy to the cell.
· It is known as “power house of thecell”.Golgi bodies:· Golgibodies secrete enzymes andhormones.· It is in the tubular structure.
.· It contain proteins..Endoplasmic reticulum:· It involves in transportation of materials.· It involves protein synthesis.
Ribosome:· It is called protein factories of thecell.Lysosomes:· It helps in intracellular andextracellular digestion.· It is called suicidal bags of the cell.
Centrosome:· It is present only in animal cell.· It is help in cell division.Vacuoles:· They control intracellular pressure.· They store cell sap. Plantcell:The plant cell differfrom animal cell by,· The centrosome is absent in the plantcell.· Plants are rigid in shape.
· They have plastids.· They have large vacuoles.Cell wall:· Outer layer gives shape to the cell.· Made up of cellulose. Plastids:· They contain pigments.
Classified into 3 types:1.Chloroplast – it is a green pigment2.Chromoplast –it is an orange and yellow pigment3.Leucoplast –it has no pigmentDifferencebetween plant cell and animal cell: Plant cell Animal cell Cell wall is present Cell wall is absent Large vacuoles are present Small vacuoles are present Chloroplast is present Chloroplast is absent. Rigid in shape not in rigid shape