Cell Diversity Cells are not identical they diversify

Cell Diversity Cells are not identical – they diversify their structure to suit their function

Types of Cells Nerve Cells Red Blood Cells Muscle Cells

Tissues A Tissue is a group of similar cells that are adapted to carry out the same function

Plant tissues Dermal tissue - A single layer of cells that surrounds the different parts of a plant - Epidermis protects the plant Vascular Tissue - Transports materials around the plant - Xylem transports water and minerals around the plant Phloem transports food from the leaves to the other parts of the plant

Animal Tissues n Muscle Tissue can contract n Nervous Tissue composed of nerve cells called neurons

Tissue Culture n Tissue culture is the growth of tissues in or on an artificial medium outside an organism n The tissue sample is removed from a plant or animal and grown in glassware ( in vitro) or in a bioreactor under carefully controlled conditions n Growth is by mitosis and produces a cluster of identical offspring - a clone

Conditions necessary for Tissue growth Oxygen n Nutrients n Growth factors and hormones n Correct p. H n Optimum temperature n Sterile conditions n Freedom from competition n

Stages in Tissue Culture Example of tissue culture is Organ transplants n Skin cells obtained n Enzymes added n Individual Cells isolated n Controlled culture medium n Sheets of cells grown

Applications of tissue cultures n Virus reproduction n Hela cells used to grow and investigate viruses n Micro propagation of plants n Produces exact copies n Quickly produces mature plants n Doesn’t need pollinators or seeds n Producing plants that are disease resistant and virus free

Applications of tissue cultures n Growing human tissue for organ transplants Skin cells n Liver cell n Pancreas cells n n Producing biotechnology products n Insulin n Interferon n Pregnancy testing kits n Drug testing kits n Cancer testing kits

Organs n n An organ is a structure composed of a number of tissues that work together to carry out one or more functions Examples ¨ Root ¨ Stem ¨ Leaf ¨ Flower ¨ Seeds ¨ Fruit - Heart - Stomach - Intestine - Liver - Lungs - Skin

Systems n A system consists of a number of organs working together to carry out one or more functions Animal Systems • Digestive • Circulatory • Nervous • Urinary • Endocrine • Skeletal • Muscular • Reproductive