The UPSC mains GS-3 paper syllabus has various subjects like Economics, Science and Technology. Science and technology in UPSC is mostly concerned with current Affairs. but it is necessary to understand the basics of science. Basics of Biology starts with Cells, This article will give aspirant an idea of the basics of Human body cells.


  • What are cells?
  • Types of Cells


Cells in the human body number in the trillions and come in all shapes and sizes.

These tiny structures are the basic unit of living organisms. Cells comprise tissues, tissues make up organs, organs form organ systems, and organ systems work together to create an organism and keep it alive.

Each type of cell in the human body is specially equipped for its role. Cells of the digestive system, for instance, are vastly different in structure and function from cells of the skeletal system. Cells of the body depend on each other to keep the body functioning as a unit. There are hundreds of types of cells, but the following are the 11 most common.


Stem Cells

Stem cells are unique in that they originate as unspecialized cells and have the ability to develop into specialized cells that can be used to build specific organs or tissues. Stem cells can divide and replicate many times in order to replenish and repair tissue. In the field of stem cell research, scientists take advantage of the renewal properties of these structures by utilizing them to generate cells for tissue repair, organ transplantation, and for the treatment of disease.

Bone Cells

One of the strongest cells in the body bone cells are connected through calcium and phosphate. These give your body strength and support in its skeletal system. There are many different types of bone cells in the body: Osteoclasts, Osteoblasts, and Osteocytes. Each cell plays a different part in the body and performs a different task. Osteoclasts aid in bone resorption releasing enzymes and acids to help the process of breaking down bones. Osteoblasts help form new bones by managing bone mineralization. Osteoblast cells form osteocytes which are found in the bone. These cells produce growth on the bone in response to strain and help keep calcium balanced. Without bone cells you wouldn’t have your skeletal system.

Blood Cells

From transporting oxygen throughout the body to fighting infection, blood cell activity is vital to life. Blood cells are produced by bone marrow. The three major types of cells in the blood are red blood cells, white blood cells, and platelets.

Blood cells are of course very important for our body! They transport oxygen through the body, fight infections, and are critical to our body. There are different types of blood cells in the body such as red blood cells, white blood cells, and platelets. Each of these cells perform a different task in the bloodstream. Red blood cells carry oxygen through the body while white blood cells fight off diseases and illnesses. Platelets clot the blood to prevent too much blood loss. For example when you cut your finger platelets come together to stop the cut from bleeding. Each of these three cells are produced through bone marrow.

Muscle Cells

Muscle cells form muscle tissue, which enables all bodily movement. The three types of muscle cells are skeletal, cardiac, and smooth. Skeletal muscle tissue attaches to bones to facilitates voluntary movement. These muscle cells are covered by connective tissue, which protects and supports muscle fiber bundles.

Cardiac muscle cells form involuntary muscle, or muscle that doesn't require conscious effort to operate, found in the heart. These cells aid in heart contraction and are joined to one another by intercalated discs that allow for heartbeat synchronization.

Smooth muscle tissue is not striated like cardiac and skeletal muscle. Smooth muscle is involuntary muscle that lines body cavities and forms the walls of many organs such as kidneys, intestines, blood vessels, and lung airways.

Fat Cells

Fat cells, also called adipocytes, are a major cell component of adipose tissue. Adipocytes contain droplets of stored fat (triglycerides) that can be used for energy. When fat is stored, its cells become round and swollen. When fat is used, its cells shrink. Adipose cells also have a critical endocrine function: they produce hormones that influence sex hormone metabolism, blood pressure regulation, insulin sensitivity, fat storage and use, blood clotting, and cell signaling.

Skin Cells

Your skin is made of multiple layers of skin cells including epithelial and connective tissue, along with a subcutaneous layer. The outermost layer is made of many different types of cells packed tightly together. These cells include: Keratinocytes, Merkel cells, Langerhans cells, and Melanocytes. As you may be able to guess Keratinocytes produce keratin proteins, which block your body from toxins. Merkel cells are what give you the ability to feel when you touch an item. Langerhans cells are antigens for the skin. If there is a cut that becomes infected these cells fight that infection for your body. Melanocytes produce the melanin giving your skin its color.

Your skin is the largest organ in your body. It protects you from dehydration, germs, damage, and stores fats and vitamins within.

Nerve Cells

Nerve cells or neurons are the most basic unit of the nervous system. Nerves send signals between the brain, spinal cord, and other body organs via nerve impulses. Structurally, a neuron consists of a cell body and nerve processes. The central cell body contains the neuron's nucleus, associated cytoplasm, and organelles. Nerve processes are "finger-like" projections (axons and dendrites) that extend from the cell body and transmit signals.

Cartilage Cells

Cartilage cells are all over the body forming a firm tissue essential to the structure of your body. Cartilage is a firm tissue found in between bones, in your ears and nose, and even between the vertebrae of your spinal cord. However, because there are no blood vessels in cartilage this tissue repairs much slower than most and nutrients are diffused from surrounding tissue. However, without cartilage much of the body would not be bendable and flexible.

UPSC Aspirants should understand the topic clearly and make sure to keep a track of Current affairsin Science and technology. To read more articles on Scienceand technology click here