How does a cell become an organism?

Today, you will learn… that cells of similar structures are organised into tissues that several tissues may make up an organ that organs are organised into systems to explain the significance of division of labour

What are the main functions of a cell? Let’s discuss: What are the main functions of a cell? What are the main functions of an organism? Pass out one piece of track to each student *

Unicellular Organisms Paramecium Amoeba

Unicellular Organisms Paramecium Microscopic organism Found on surface of water (eg: pond, river) Has hair surrounding the body for movement Has a mouth Can/does it perform all functions it needs to stay alive?

Unicellular Organisms Amoeba Often found at bottom of ponds or under rocks Does not move fast No arms, legs, eyes, mouth Eats by surrounding its prey with its body Lives only for 2 days Reproduce by splitting itself into 2 new amoebas *

How do we go from to ?

Multicellular Organisms Have many different cells Different cells perform different functions Examples Plants Humans

Cells in a Human Examples Red blood cell (transport oxygen) Nerve cell (have nerve fibres to transmit signals to and from the central nervous system)

Cells in a Plant Examples Root hair cell Leaf guard cell

From cells to tissues Tissue Group of similar cells that are specialized to perform a particular function Students build a length of track at their tables *

Tissues in a Human Epithelial tissue Covering or lining tissue to protect structure beneath it Connective tissue Joins, stores or supports all parts of an organism

Tissues in a Human Muscle tissue Cause movement Nerve tissue Carry messages from one part of body to another by conducting electrical signals

Tissues in a Plant Epidermal tissue Protects plant against injury and losing too much water Vascular tissue Transports materials within a plant

Tissues in a Plant Photosynthesis tissue Carries out photosynthesis in a plant

From Tissues to Organs Organ Group of specialized tissues that are gathered in a certain part of the body to perform a particular function together Students build an oval with their tissues *

Organs in a Human Examples Skin Lungs Heart

Organs in a Plant Examples Leaves Stem Roots Flowers

From Organs to Systems System Different organs working together to perform a major function in an organism Connect the different ovals to form a layout *

Main Organ Systems in a Human Respiratory system Digestive system Blood circulatory system Skeletal system Muscular system

The Human Body - An organism CELLS TISSUES ORGANS SYSTEMS ORGANISM

Division of Labor Each cell in a multicellular organism does not perform all the bodily functions. Each type of cell specialises in performing one particular function. Different functions in a multicellular organism can be performed at the same time by division of labour.

Division of Labor Division of labor Sharing different functions in an organism among its cells, tissues, organs and systems nsures smooth running and effective working of the different parts in an organisms as well as the organism as a whole