Nervous tissue is made up of millions of nerve cells called neurons. The neurons are highly specialized cells which controls and co-ordinates the body activities and forms a system called Nervous system. Nervous system consists of three types such as CNS, PNS and ANS.
The simplest form of cell, prokaryotic cell is also the oldest form of life on the earth. Distinctively known for the cellular structure, prokaryotic cells are those which lack membrane-bound nucleus and other cell organelles.
Blood is the fluid in living organism that transports oxygen and nutrients to the cells in the body. It consists of Red Blood Cells(Erythrocytes), White Blood Cells(Leukocytes) and platelets (Thrombocytes).
Platelets are the part of the blood that helps to prevent blood loss through wounds by forming clot and fight off infections.
1µl (microlitre) of blood contains
Count - The number of leucocytes per microlitre of blood is called total leucocytecount (TLC). A normal adult human consists of 5,000–10,000/mm3 of blood. Rise in WBCs count is called leucocytosis. Increased TLC shows that there is acute bacterial infection.
Prokaryotic cells are different from eukaryotic cells in many different ways. These bases of differences are clearly mentioned in the following table.
|
Basis of Difference |
Prokaryotic Cells |
Eukaryotic Cells |
|---|---|---|
|
Origin |
Prokaryotic cells are the earliest forms of lives on the earth and simples cells which evolved nearly 3.5 billion years ago. Almost 1.5 billion later, more advanced and complex cells called eukaryotic cells evolved which make up superior organisms such as plants and animals.
Eukaryotic cell are the developed, advanced and complex forms of cells. They are the building block or smallest unit of life of organisms as simple as amoeba and protozoa to the most complicated plants and animals.
Significantly bigger than the prokaryotic cells, eukaryotic cells have diameter ranging from 10µm -100µm. Inside it are various cell organelles which performs individual functions and support cell life.
More advanced and developed than the prokaryotic cell, eukaryotic cells are those which have true or membrane-bound nucleus along with other nucleus bound cell organelles.
From unicellular organisms like protozoa and amoeba, all plants and animals, including human beings are made up of eukaryotic cells.
Prokaryotic cell is one of the simplest forms of cell which makes up the unicellular microscopic organisms called acrhaea and bacteria. However, there are some cyanobacteria which are multicellular.