The adaptation of cells to their functions,their size, and shape

1.THE GENERAL FEATURES OF HUMAN CELLS
The cell is the structural functional unit of all known living organisms it is the smallest unit of an organism that is classified as a living and is often called the building block of life .Like ourselves, the individual cell that forms our bodies can grow reproduce, process, information, respond to stimuli and carry out an amazing array of chemical reactions ,as the twenty first century opens we face an explosion of new data about components of cells what structures they contain how they touch and influence each other. The human body is composed of countless millions of units called cells .In an animal like a human there are
These cells are scavengers that phagocytise killed micro organisms and are therefore effective at direct destruction of pathogens and clean up of cellular debris from site of infection.
STRUCTURE OF HAEMOGLOBIN (appendix 5)

STRUCTURE AND FUNCTION OF NEURONS

Neurons are also involved in the eukaryotic cell; they transmit information by electrical impulses from one neuron to another. They are three different types of neurons the sensory, motor and interneuron. The sensory neuron transmits impulses in wards from sense organs to the CNS whilst the motor transmits impulses from the CNS which consist of the brain and the spinal cord ,to muscle and glands .The interneuron is found only in the CNS it connects motor and sensory neuron it is known by the term multi polar .The neuron has three parts soma which is the cell body ,dendrite and axon .Dendrites receive electrical impulses from other neurons and carry it to the soma .The axon is a long nerve fibre that sends electrical impulses from the soma to another connectivity neuron .It has mitochondria and microtubule that aid in the transportation of protein produced in the soma ,most neurons have fatty myelin sheath formed protein and phospholipids that is laid down as sheath around the axon .The myelin sheath protects insulate the nerve fibres and also increase the rate of transmission of nerve impulses .The electrical impulses are transmitted through