EVERYDAY BIOLOGY. PHASE v.....

Cell Membrane: This is selectively permeable-allowing certain materials to enter or leave the cell.

Cell Wall: Found surrounding cell membrane in plant cells. It is thicker than cell membrane, rigid because it contains cellulose. It gives the plant its firm shape.

Centrosome: Is a minute granule made of two parts at right angle too one another.
It is concerned with spindle formation during cell division.

Chloroplasts are larger organelles that contain the green pigment (chlorophyll) in green plants.

Endoplasmic reticulum is a complex system forming a tubular meshwork extending throughout the cytoplasm. It is responsible for transport of materials within the cell.

Golgi bodies as membranous structures arranged like coiled tubule. They are enzyme bags storing proteins digesting enzymes which like sugar with protein. Golgi bodies also play a role in the formation of extra length of cell membrane after cell division.

Lysosome are found in animals only. Enzymes are stored in them particularly the cytolytic enzymes which break down materials inside the cell. They are known as suicide bags because they get rid of old warn-out cells.

Mitochondrion is a large cell organelle with structure double membrane with the inner folded to form shelf like structure. Mitochondrion is the site of oxidation of food materials to produce energy needed for cellular activities.

Nucleus is the largest organelle of the cell. It is biconvex and discoidal in shape. It consists of membrane-bound materials of which the nucleus and chromosomes are the most distinct. The nucleus controls the entire cellular activities while its chromosomes are the hereditary material, which are responsible for carrying characters from parents to offspring.

Ribosomes are the smallest organelles in the cell. They are spherical bodies made up mainly of ribonucleic acid (RNA) and arranged alongside endoplasmic reticulum. Ribosomes are sites for assemblage of amino acids into proteins.