Cell-The basic unit of all living things except viruses. In advanced organisms, cells consist of a nucleus (which contains genetic material), cytoplasm, and organelles, all of which are surrounded by acell membrane.
Plant and animal cells have several differences and similarities. For example, animal cells do not have a cell wall or chloroplasts but plant cells do. Animal cells are round and irregular in shape while plant cells have fixed, rectangular shapes.
The function of the bone, muscle, nerve cells are
Cardiac muscle cells, found only in the heart, are striated and branching (with one nucleus); they are joined by intercalacted discs which allow the cells to synchronize the beating of the heart
Skeletal muscle cells, long, striated, multinucleate cells under voluntary control, are responsible for the movement of skeletal muscles.
Although the system forms a unit it can be divided into the following parts: the central nervous system (CNS) which consists of the brain and spinal cord, the nervous system consists of the nerves outside the CNS which connect the brain and spinal cord to the organs and muscles of the body.
Digestive-The function of the digestive system is digestion and absorption.Digestion is the breakdown of food into small molecules, which are then absorbed into the body. The digestive system is divided into two major parts: The digestive tract (alimentary canal) is a continuous tube with two openings: the mouth and the anus.
Circulatory-The circulatory system functions in the delivery of oxygen, nutrient molecules, and hormones and the removal of carbon dioxide, ammonia and other metabolic wastes. Capillaries are the points of exchange between the blood and surrounding tissues.
Respiratory-The primary function of the respiratory system is to supply the blood with oxygen in order for the blood to deliver oxygen to all parts of the body. The respiratory system does this through breathing. When we breathe, we inhale oxygen and exhale carbon dioxide.