LifeLine

In our human body, each cell plays a different role and together, they create the human body. This is made possible by a biological process called cell specialization, or cell differentiation. It’s the reason why your skin protects you, your muscles contract, and your neurons fire signals.

Cell specialization refers to the process by which unspecialized cells (stem cells) develop into distinct, different cell types with unique structures and functions. These specialized cells are tailored to perform specific tasks. Without cell specialization, multicellular organisms like humans wouldn’t exist. 

How do specialized cells arise from unspecialized cells 

The first step in developing a new organism is the continual division of cells to produce a blastocyst and then an embryo. All these cells are capable of future division, and they are known as embryonic stem cells. A stem cell can repeatedly divided into more stem cells, which are unspecialized (eg. have yet to chrome special types of cells), and later can differentiate into mature cell types, such as muscle, blood, nerve cells, etc. At the next stage of embryo development most cells develop into the tissues and organs that make up the organism. However a very few cells within these tissues do retain many of the properties of the embryonic stem cells, and these are called adult stem (cell differentiation).

So unspecialized cells are stem cells and stem cells have the ability to change into any cell/function depending on if they are multipotent or pluripotent. But the way that it happens is first the zygote becomes a blastocyst which is the inner mass of the cell and it becomes an embryo and the embryo is a stem cell, its a type of stem cell (embryonic stem cell). Embryonic cells are also pluripotent which means they can turn into any cell/function. So the embryonic stem cell comes from the inner cell mass and it changes into a specialized cell with a specific function like being a red blood cell, white blood cell, liver cells, etc. So from being an undifferentiated cell it becomes a differentiated cell with a particular function.

Specialized cells 

Plant epidurals cells 

The epidermis and its waxy cuticle provide a protective barrier against mechanical injury, water loss, and infection. Various modified epidermal cells regulate transpiration, increase water absorption, and secrete substances.

• Are important in forming a boundary from outside. 

• They help plants to not lose water. 
• They are present at the top and bottom of the leaf
• Layers could be one layer thick or several layers thick based on the environment
• Some of these don’t even contain chloroplast

Red blood cells 

RBC carries oxygen around the body, which is needed for respiration. They are well suited to this function because:

• They contain hemoglobin, which carries oxygen molecules.
• They don’t have a nucleus, allowing more space to carry oxygen.
• They are a flat disc shape with dips on both sides (biconcave). This gives them a large surface area, and the best chance of absorbing as much oxygen as they can in the lungs.

White blood cells 

WBC are part of the body’s immune system. They help the body fight infection and other diseases. They locate microbes that enter the body and then destroy them. 

Sperm Cell

Sperm are the male sex cell. They are made in the testes after puberty. They join with an egg cell during fertilization to form an embryo which can then develop into a new life. The following features make them well suited to this function:

• A tail moves them towards an egg cell.
• Many mitochondria release energy for movement.
• Part of the tip of the head of the sperm, called the acrosome, releases enzymes to digest the egg membrane to allow fertilization to take place.
• The haploid nucleus contains the genetic material for fertilization.

Eggs 

Eggs are the female sex cells. They are made in the ovaries before birth. Usually, one egg is released each month during the menstrual cycle, but sometimes this number may be higher. They join with a sperm cell during fertilization to form an embryo which can then develop into a new life. They are well suited to this function because:

• The egg cell’s cytoplasm contains nutrients for the growth of the early embryo.
• The haploid nucleus contains genetic material for fertilization.
• The cell membrane changes after fertilization by a single sperm so that no more sperm can enter.

Nerve cells

Nerve cells transmit electrical signals in the nervous system. They are well suited to their function because:

• They are thin, and can be more than one meter long in your spinal cord. This means they can carry messages up and down the body over large distances very quickly.
• Nerve cells have branched connections at each end. These join to other nerve cells, allowing them to pass messages around the body.
• They have a fatty (myelin) sheath that surrounds them. The fatty sheath increases the speed at which the message can travel.

Muscle cells 

Muscle cells are found in bundles which make up our muscles. These cells are able to contract (get shorter) and relax (return to original length). There are different types of muscle cells, each perfectly adapted to its function. 

Here are some examples:

Cardiac muscle cells – Contract and relax to pump blood around our bodies for the rest of our lives.

Smooth muscle cells – Make thin sheets of muscle, such as the stomach lining. They can be arranged in bundles. 

Cell specialization allows unity in diversity. Millions of cells, performing millions of tasks, all working in harmony. It’s remarkable that even the smallest parts of life carry such complexity.