What is a Cell?

A cell is the basic unit of life and some organisms are made up of trillions of cells, while others, like bacteria, are only a single cell.

Cells can be so incredibly small that you need a microscope to see them, but once you discover them, you realize that they are an entire world inside the bodies of living things.

Cells are often called by the nickname of miniature factories, and each cell has a very specific job as part of the whole. Cells work both independently and with each other, so that everything in the living organism runs well.

The job that a cell has differs based on what type of cell. As an example, your blood cells assist in carrying oxygen to your muscles and body organs.

Cells are also what we use to identify something as “living.” Cells are part of every living thing around you, from the trees in your backyard and the birds flying across the fields.

Cell as the small units of our bodies that give us life and they are constantly on the move.

It might be difficult to think of a single cell as a living organism but even bacteria cells are part of those defined as living creatures. While single cell are considered living, they are different from what are called “complex cell systems” such as humans and other animals.

The human body has around 37 trillion cells, and they work together in a kind of harmony to keep our systems balanced and alive.

Each cell has a function as part of their small factory duty and it’s important that the cells stay in tip top shape to accomplish their tasks.

What is the size of a cell?

There are various cell sizes and some are so tiny that only the most powerful microscopes can see them compared to others that can be seen by the human eye and are around the size of the “period” dot at the end of a sentence.

Cell Types

If you think about all of the functions of all of the living creatures on earth, the number is almost impossible to consider. There are thousands of creatures and therefore millions of different cell types, and cells are unique for each living thing.

To make things a bit easier, scientists have divided cells into two main categories and they are defined by the condition of their “nuclei” or center:

Prokaryotic cells that have a nuclei which aren’t bound by a membrane.
Eukaryotic cells have a nuclei that are bound by a membrane.

Eukaryotic cell types are grouped into two additional categories: animal cells and plant cells. We humans have eukaryotic cells that are animal cells.

Peering Inside a Cell

Each cell has a tiny organ inside that are called cell organelles. Organelle translates to “small organ” and in fact, these are responsible for make sure the cell has everything that it needs to function.

They bring in the food, get rid of any waste, protect and repair the cell, and even help it to grow and reproduce. Each organelle has a very specific duty to assist the cell and when one of the organelles stops in its job, the cell will die. In addition to organelles, cells also have proteins.

There are two major compartments inside the cell membrane: the cytoplasm that holds structures that consume and then transform energy so that the cell can do its job –and- the nucleus which holds the genetic material of the cell so that it can divide and reproduce.

Fun Cell Facts

  • Motor neurons are the longest cells in the human body and have been measured as long as 1.37 meters/4.5 feet. These cells run from the lower spinal cord to the big toe.
  • Red blood cells carry oxygen throughout your entire body and they are created inside the “marrow” of your bones.
  • You need a microscope to see the largest cell which is a fertilized egg. Even that’s too small to see with the naked eye.
  • Human cells have a membrane that is a kind of container that holds the contents together. The surprising thing is that the container or “sac” has receptors to let other cells know what type it is.
  • It’s estimated that the number of cells that die in an adult male is around 96 million per minute. (Good thing that there were 96 million that grew and replaced them)
  • You know that you shed your dead skin on the outside of your body. The inside of your body also sheds dead cells and they pass through and out of your body with waste.

The life span of a cell depends upon what type of cell:

  • White blood cells can live for around 13 days.
  • Cells on your skin outer layer live for around 30 days.
  • Red blood cells live for nearing 120 days.
  • Liver cells live around 18 months.

Interesting Facts about Biology

  • Living creatures that exist and thrive in environments that would be toxic for almost all other creatures are called “extremophiles.” They can be in deep dark caves, in ice cold arctic conditions, or deep under water next to tubes that give off toxic chemicals.
  • Your nose can remember over 50,000 different scents.
  • Your nose and ears never stop growing throughout your life.
  • A sneeze measures around 100 mph
  • The brain doesn’t have any nerve endings and therefore can’t feel any pain.
  • The brain is more active at night than during the day.

What is a Cell Quiz

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