Basic Structure of a Cell

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Slide 38

The cell is the Basic Unit of Life

Cell is the smallest unit of living organisms

Unicellular organisms are made of one cell only

The cells of multicellular organisms are specialized to perform different functions

e.g. mesophyll cells for photosynthesis and root hair cells for water absorption

Slide 39

Levels of organization

Cells are grouped together and work as a whole to perform special functions

Slide 40

Tissue

A group of similar cells to perform a particular function

Animals : epithelial tissue, muscular tissue

Plants : vascular tissue, mesophyll

Slide 41

Organ

Different tissues group together to carry out specialized functions

Heart : consists of muscles, nervous tissue and blood vessels

Leaf : consists of epidermis, mesophyll and vascular tissue

Slide 42

Stoma

Air Space

Spongy Mesophyll Cell

Chloroplast

The Structures of a Leaf (Plant Organ)

Palisade Mesophyll Cell

Slide 43

The Structures of a Heart (Animal Organ)

Slide 44

System

Several organs and tissues work together to carry out a particular set of functions in a co-ordinated way

Human : digestive, respiratory, excretory, circulatory and reproductive systems

Plant : root and shoot systems

Slide 45

Human Body Systems

Examples of systems :

Digestive System

Respiratory System

Circulatory System

Nervous System

Reproductive System

Slide 46

Examples of a Human Body System

Slide 47

Examples of a Human Body System

Slide 48

Examples of a Human Body System

Circulatory System

Slide 49

Examples of a Human Body System

Nervous System

Slide 50

Levels of Organization

CELLS (muscle cells,nerve cells)

TISSUES (muscle, epithelium)