Before answering the question as to why are cells the basic unit of all life not organelles, it is important to gather the right information on cells. A cell is the smallest unit which can exist independently and perform essential functions of life. Cells can divide and form tissues and further into organs and systems. That is why, it is an organism. At the cellular level, metabolic processes take place that keep the organism alive.
Hence, the cell is called the fundamental unit of life. Cell organelles are the specialized organs inside a cell that perform a particular function. They cannot exist independently but they work together in a specific environment.
Cells as the basic unit of life
A cell is the smallest unit of a living organism and is the basic building unit of all organisms. Let us close our eyes and imagine a brick wall. The wall is made up of the basic building block which is the brick. Similarly, our body is made up basic building blocks called cells.
Cells as building blocks
A living organism can be either be made of one cell like the bacteria or many cells like a human. Hence, the cells are considered as the basic building blocks of all organisms. Many cells of one kind connects with each other and does a shared function to form tissues; many tissues bond together to form an organ such as the stomach, heart, or brain; and many organs combine together to form an organ system such as the digestive system, circulatory system, or nervous system. Then several systems operate together to form an organism such as the human being. There are different types of cells categorized into two broad divisions: prokaryotic and eukaryotic. For example, animals and plants fall under eukaryotic cells whereas bacterial cells fall under prokaryotic cells.
Types of specialized cells
Our body is made up of many kinds of cells, each cell having its own specialized purpose. For example, the function of epithelial cells is to protect the surface of the body and cover the organs and body cavities. Bone cells support and protect the body. Cells of the immune system keep off the bacteria. Blood and blood cells transport nutrients and oxygen throughout the body and removes carbon dioxide. The cells play a vital role in the growth, development, and daily maintenance of the body.
Microscopes help to magnify and visualize cells and cellular components not visible to the naked eye.
The functional unit of life
The cell is the most vital of all the body forming unit. The organs in our body are effects of arimidex made of cells. Cells divide and multiply to create new organs and gametes. The cell is called a functional unit of life because of the following reasons:
- The cell is the structural and functional unit of life because all living organism are composed of cells.
- Cells perform various life processes which are needed for sustaining life.
- Cells give the form ad structure, make nutrients and change them into useable energy.
- Multicellular organisms are made up of specialized cells that does specific functions.
- Cells come in small and easily recognizable packages because cells are covered by a structure called the cell membrane which acts as a clear boundary between the cell’s internal and external environments.
- The blood has RBC and the task of this cell is to transport oxygen and carbon dioxide.
- A specialized cell is the photoreceptor cell which is located in the eye. The task of this cell is to convert light into signals which influences the biological processes.
What are cell organelles?
Cells can be described as the basic unit of life which are essential for all life’s processes.
A cell replicates itself and so it is the building block of life. Fluid is present inside each cell which is known as cytoplasm and is surrounded by a membrane. In the cytoplasm, there are many biomolecules present such as lipids, nucleic acids and proteins.
The cellular structures which are there are called cell organelles that are in the cytoplasm. Cells have different shapes and sizes like the blocks of building structures.
Do you know the answer of the below question?
- The living component of a cell wall is
- A) middle lamellae
- B) pit pair
- C) secondary cell wall
- D) plasmodesmata
Definition of cell organelles
The cell parts are known as cell organelles which have a membrane (layer) and non-membrane (non-film) bound organelles. They are located in the cells and are of various designs and capacities. They perform tasks for the cells to function properly. Some of them work to give shape and backing, while some aid in the movement and generation of cells. The organelles which are in a cell are divided onto three categories according to the presence or absence of membrane:
Organelles without membrane: The cell membrane, Ribosomes and Cytoskeleton are non-membrane-bound cell organelles which are present in prokaryotic cells and the eukaryotic cell.
Single membrane-bound organelles: These are vacuole, lysosome, Golgi bodies, endoplasmic reticulum present in a eukaryotic cell.
Twofold film bound or double-membrane organelles are nucleus, mitochondria and chloroplast. They are two fold layer bound organelles which are there in a eukaryotic cell.