A group of same/similar cells with a similar structure and function working together to carry out a particular job.
Organ
A collection of different tissues working together to carry out a perticular job.
Organ system
A group of different organs that work together to carry out a particular job.
Cell differentiation
Enables the bodies of multicellular organisms to develop in many different ways enabling many different body forms. E.g. muscle cells enable some animals to rapidly move, whilst palisade cells enable plants to make food via photosynthesis.
Nucleus
Controls the activities of the cell ans contains DNA/chromosomes/genes.
Cytoplasm
Site of metabolic reactions.
Cell membrane
Controls the passage of substances into and out of the cell.
Mitochondria
Site of aerobic respiration to release energy.
Ribosomes
Site of protein synthesis
Chloroplasts
Site of photosynthesis. Absorb light energy to make food. Contain chlorophyll.
Cell wall
Keeps the cells shape and keeps the cell rigid. Supports the cell.
Permanent vacuole
Helps keep the cell turgid (swollen). Contains cell sap.
Stem cells
Found in human embryos and adult bone marrow.
Yet to differenciate.
Capable of differentiating into any type of specialised cell that makes up the body.