Cell Diversity

Definitions Tissue - group of cells adapted to carry out the same function. E.g. Blood, Xylem Organ - a group of tissues working together to carry out a function. E.g. heart, seeds System - a group of organs working together to carry out a function. E.g. Digestive, Circulatory

Tissues Note: Tissues have one cell type Plant Tissue Animal Tissue

Plant Tissues

Plant Tissue Dermal Vascular Ground Meristematic

Dermal Tissue Single layer of cells that surround parts of plant Function – protection & prevention of water loss E.g. Epidermis - like skin of plant Cuticle - waterproof layer on epidermis

Vascular Tissue Transportation of Materials / Support Two Types Xylem - transportation of water Phloem - transportation of food Both of these are found within a ‘vascular bundle’

Xylem and Phloem

Vascular Bundle

Ground Tissue Occupies the space between dermal and vascular tissues Store sugar and starch

Meristematic Tissue Used during cell division (mitosis) Structure: Small, thin walls, no vacuole Location: Roots, Shoots and Nodes

Animal Tissues

Types of Animal Tissues Epithelial Connective Muscular Nervous

Epithelial Covers internal and external surfaces of the body

Connective Tissue Joins and supports body structures Structure: Cells found in matrix Examples - adipose tissue (stores fat under skin), cartilage, blood

Muscular Tissue Ability to contract Found in muscles and organs

Nervous Tissue Made of neurons Carry impulses to and from brain and spinal chord (CNS)

Tissue Culture

Tissue Culture This is the growth of tissue in an artificial medium In-vitro – growing cells / tissues in an artificial medium (in a test tube). In-vivo – growing cells / tissues inside an organism Bioreactor – the apparatus used in tissue culturing & other biotechnological activities.

Micro-propagation The growth of large numbers of plants from very small plant pieces Specific plant is cut into small pieces The pieces are grown in lab in medium. A ‘clump’ of cells called a CALLUS develops Growing conditions changed Young plant embryo forms Seedling develops Young plant is ‘planted out’ in usual way

Micro-Propagation Advantages of micropropagation Large numbers produced in a short time Genetically identical (clones) are produced Inexpensive

Organs

Organs A number of tissues working together to carry out the same function Plant Organs Leaf - composed of dermal, ground & vascular tissue Animal Organs Heart – composed of blood, cardiac muscle & nervous tissue

Organ Systems A number of organs working together to carry out the same function Plant System Transport System – xylem & phloem Animal Systems Circulatory – heart, blood vessels & blood