what are complex tissues? n what are some examples of it? anyone to help me/useful websites?

Answer 1

generally there are 4 main tissues available in human body, tissue mean a group of cells that perform the same function

epithelium/ epithelial tissue = skin cells
connective tissue = bone cells
muscle tissue = muscle cells+
nervous tissue = nerve cells + glial cells

Answer 2

There are four basic types of tissue in the body of all animals, including the human body and lower multicellular organisms such as insects. These compose all the organs, structures and other contents.

Epithelium - Tissues composed of layers of cells that cover organ surfaces such as surface of the skin and inner lining of digestive tract: the tissues that serve for protection, secretion, and absorption.
Connective tissue - As the name suggests, connective tissue holds everything together. Some people consider blood a connective tissue. It should be noted that blood is not 'considered' connective tissue, it is connective tissue. (i.e. cells of connective tissue (blood) separated by an inorganic material (plasma). Plasma is the extracellular matrix that includes everything but the red/white blood cells. These tissues contain extensive extracellular matrix.
Muscle tissue - Muscle cells contain contractile filaments that move past each other and change the size of the cell. Muscle tissue also is separated into three distinct categories: visceral or smooth muscle, which is found in the inner linings of organs; skeletal muscle, which is found attached to bone in order for mobility to take place; and cardiac muscle which is found in the heart.
Nervous tissue - Cells forming the brain, spinal cord and peripheral nervous system.

Plant tissues
Examples of tissue in other multicellular organisms are vascular tissue in plants, such as xylem and phloem. Plant tissues are categorized broadly into three tissue systems: the epidermis, the ground tissue, and the vascular tissue. Together they are often referred to as biomass.

Epidermis - Cells forming the outer surface of the leaves and of the young plant body.
Vascular tissue - The primary components of vascular tissue are the xylem and phloem. These transport fluid and nutrients internally.
Ground tissue - Ground tissue is less differentiated than other tissues. Ground tissue manufactures nutrients by photosynthesis and stores reserve nutrients.

http://en.wikipedia.org/wiki/Tissue_%28biology%29