Are bacteria alive?

Exploring the Tiny World: Microorganisms!

Our living world comprises living organisms of varying sizes and structures. So whilst some maybe as large as human beings and animals, some may be so small that either they are rendered completely invisible, or can only be seen under a powerful instrument called a microscope.

In our topic of discussion today, we will talk about one particularly common form of micro-organsim, known as bacteria.


What Are Bacteria?

In simple words, Bacteria are tiny, unicellular organisms. Their cellular structure is quite unique, since not only are they comprised of just one cell in totality, but also lack a properly arranged nucleus in the cell. There is no presence of organellles inside them either.

They have a maximum size of a few micrometres only and can have a number of shapes. These are invisible to the naked eye, and can only be seen by a microscope. They can live in almost all kinds of surfaces and circumstances, and in a variety of temperatures.

Bacteria In Our Body

There is the presence of Bacteria in our bodies as well. There are many different kinds of bacteria present in the body, and they play a very important role in the body.  A massive presence of it is in our digestive system, which helps in the breakdown of food and also release important nutrients in the process. These nutrients are highly beneficial for the human body.

However, there are some other types of bacteria that are rather harmful and instead can produce toxic substances, which have the ability to make us sick. These types of bacteria are in specifically called Germs.

Structure Of The Bacteria

Irrespective of its size, a bacterium does have a definite structure, which allows it to live, breed and move as required. Since these are living organisms, hence, it would be incorrect to state that bacteria are non-living entities, just by their size.

Cell Membrane

The cell membrane is a semi-permeable membrane that surrounds a bacterial cell. It allows easy intake and release of chemical substances to and from the bacteria. These are the chemicals which essentially assist the bacteria in its growth.


Just like the membrane, the capsule is another such layer, which protects the cell from any harm.


Flagella simply act like the tails or limbs of the bacteria, which twist and propel itself so as to induce movement of the bacteria.

Cell Wall

Cell walls too protect the bacteria from any harm and also give them their shape.


Ribosomes are like a protein-making factory in a bacterial cell. It is especially required when the bacteria reproduces itself by splitting into two parts, as these make proteins helps it rebuild and support the newly forming cell.


The inside of the cell is filled up by a fluid called Cytoplasm. The major metabolic reactions all take place in the cytoplasm of the cell.


Just like human beings, bacterial organisms too contain DNA information stored in their chromosome. In this type of organism, the chromosomes are not organized into a well-defined structure (like the nucleus) but are shaped like one big circular loop.

Fun Facts

  • A bacteria (singular: bacterium) is capable of moving 100 times its total length in about one second!
  • Bacteria have been around for at least 3.5 billion years, making them the oldest known life-form on the planet

Related questions

  1. What are the different types of shapes found in bacteria? What are they named as?
  2. Enlist some of the various kinds of diseases caused by bacteria.
  3. Which part of the human body has the highest number of bacteria present?

Fill in the Blanks

  1. Flagella helps the bacteria in  _______.
  2. _______ is also present in bacterium, just like human beings.
  3. Cell wall gives _______ to the bacterium.
  4. Cytoplasm is a  ______ substance.
  5. Cell membrane is ________ in nature.

True Or False

  • Ribosome give protection to the cell: ________
  • Bacteria is unicellular:  ______
  • Bacteria can be seen with the naked eye: _______
  • Capsule gives shape to the cell of the bacterium: ________
  • Bacterial micro-organisms are present in the human body as well: _______

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