How a Plant works: Plant Cells

Like all living things, plants are made of microscopic units called cells. All of the chemical processes are taken place inside the cells. Some plants are made up of only one cell, while large plants, like trees, are made of millions of cells. Groups of cells work together to form tissues in Higher plants. Several different types of tissue work together as organs such as roots, leaves or stems.

The Cell

All plant cells have walls made up of long fibres called cellulose. The wall forms a skin that surrounds the entire cell and together with the cell membrane, keeps the contents of the cell in while letting certain substances pass in and out.

Inside the cell wall and membrane is cytoplasm. Cytoplasm is made of 90% water and 10% minute granules of food and tiny structures called organelles. They are involved in chemical reactions, such as releasing energy and making food.

The vacuole is a large, fluid filled space containing sap. As a syrupy solution, sap carries sugars made in the plant's leave and dissolves its minerals to every part of the plant. It also keeps the cytoplasm firm by pushing against it.

The cells 'brain' is the nucleus which controls the cell functions and division. Containing the thread-like chromosomes, which carries the cell's genetic material that determines what the cell is like and how it works.

Note: The living matter in the cell- nucleus, cytoplasm, and the membrane- is known as the protoplasm.

Cells may be specialized to carry out different jobs. Such as the phloem cells which carry food through the plant, guard cells curve around a stomata (pore), and palisade cells are column-shaped and are in the leaves of the plant.

AAA Plastids and chloroplasts which contain the green pigment chlorophyll (for making foo by photosynthesis) are a few organelles found in the cytoplasm.

Plant cells are joined together along their cell walls Fluids can pass through the cell walls from cell to cell.