CELLSM

ade by Zauraiz and Izhan

CellsThe cell is the basic structural, functional, and biological unit of all living organisms. Cells are often called building blocks of life. The cell theory that was proposed by Scheiden and Schwann in 1893 stated that cells are the basic unit of life. All living things are made up of cells and cells come from pre-existent cells.Some living things such as Paramecium, Bacterium, Yeast , Algae, Euglena and Amoeba are unicellular which means that they are made up of only one cell.

Other living things like we, humans, plants and animals are multicellular organisms.

Cells are so tiny that they can only be seen under a microscope. In

1590 Dutch lens grinder Hans and Zacharias Janssen made the first

microscope by placing two lenses in a tube. A microscope magnifies objects by using lenses.

Plant and Animal CellsPlants and animals both are made up of cells but they appear different and have some differences between their organelles. Organelle is a specialized subunit within a cell that has a specific function.

The green dots are chloroplast. Animal cell Plant cell

Typical plant cell

Typical animal cell

Nucleus: It controls all the activities of the cell including cell repair. It has thread-like structures called chromosomes which is made up of DNA. Genes are part of DNA which store information and pass it on from one generation to the next.

Nucleus: It controls all the activities of the cell including cell repair. It has thread-like structures called chromosomes which is made up of DNA. Genes are part of DNA which store information and pass it on from one generation to the next.

Cytoplasm: This jelly like fluid is reduced to a thin layer due to a large vacuole. Here cell activities occur like breaking and making of materials. It contains other parts of cell such as nucleus and chloroplast.

Cytoplasm: This is a jelly-like fluid which almost covers the whole cell. Here cell activities occur like breaking and making of materials. It contains other parts of cell such as nucleus.

Chloroplast: Disc-like structures which contain a green pigment called chlorophyll to trap sunlight for carrying out photosynthesis.

Chloroplast: Absent.

Vacuole: Usually one single large vacuole which contains cell sap that has sugar, minerals and salts dissolved in water. It keeps the cell firm by taking in water.

Vacuole: Numerous and small. Contain food water and waste materials.

Cell wall: Firm and stiff structure made of cellulose and supports the cell.

Cell Wall: Absent.

Cell Membrane: Thin layer which controls the movement of materials (in and out of cell). Partially permeable.

Cell Membrane: Thin layer which controls the movement of materials (in and out of cell). Partially permeable.

Cell DivisionCell’s growth is necessary for an organism’s growth and also to replace dead and damaged cells. Cells grow through cell

division. When a cell grows to a certain size, the nucleus of the cell

makes a copy of itself. Then cell that is being divided is called parent cell. Then the nucleus eventually starts to separate itself from the

cell. Then two identical daughter cells are formed each with a

nucleus. This type of division where the genetic code is fully copied is

called mitosis.

Division Of LabourMulticellular organisms are made up of millions and trillions of cells.

All these cells perform specific functions. Different functions are carried

out by different groups of cells in an organism and this is known as

division of labour in multicellular organisms.