Cell biology or cytology is the study of the types, structure and composition of cells. Since it is the fundamental unit of life, it is essential to become familiar with its attributes before moving onto other topics in biology.
On that note, let us sneak a peek at cell biology and genetics in brief.
Why is Cell the Unit of Life?
The fact all living species are made up of cells make it the fundamental unit of life. For instance, in unicellular organisms, including amoeba, yeast, paramecium and bacteria, a single cell is responsible for all essential functions.
On the other hand, in case of multicellular organisms, cells form tissues which collectively perform various bodily functions. Notably, the shape and size of cells tend to vary based on their location and functions.
For example, they can be polygonal, cuboid, columnar, irregular or thread-like in shape. Though there are several types of cells, the most common ones are as follows –
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Sex cell
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Fat cell
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Muscle cell
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Bone cell
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Immune cell
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Blood cell
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Epithelial cell
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Nervous cell
Fun Fact: Did you know the cell was discovered by an English philosopher and architect, Robert Hooke in 1665.
What is Cell Theory?
The said theory was proposed in 1938 by Theodore Schwann and Matthias Schleiden and was later modified in 1855 by Rudolf Virchow.
The theory states that plant cells and animal cells differ from one another, with the latter not having a cell wall. Furthermore, it stated that cells’ outer membrane serves as a protective boundary and regulates the exchange of ions and molecules among other components.
Do It Yourself: Find out the limitations of the cell theory.
Based on the theory, the following are a few fundamental differences between plant and animal cells –
Differences Between Plant Cell and Animal Cell
|
Parameters |
Animal Cell |
Plant Cell |
|
Cell wall |
It is absent here. |
It is present and is formed of cellulose. |
|
Shape |
It is round and irregular. |
The shape is rectangular and mostly fixed. |
|
Chloroplast |
The chloroplast is absent in animal cells. |
The chloroplast is vital for making food and present in almost every plant cell. |
|
Vacuole |
There are one or more vacuoles presents. They are often smaller than the vacuoles in plant cells. |
There is only one central vacuole which takes up to 90% of a cell’s volume. |
|
Centrioles |
It is present in animal cells. |
It is present in only a few lower plant forms. |
|
Plastids |
Absent. |
Present |
|
Lysosomes |
It is present in the cytoplasm. |
It is not evident in plant cells. |
|
Plasma membrane |
Only cell membrane is present. |
Both cell walls and cell membranes are present. |
|
Cilia |
It is present in animal cells. |
It is not present in most plant cells. |
|
Flagella |
It can be found in some cells like sperm cells. |
It is only present in some cells like sperm of bryophytes. |
Important Cell Biology Topics
In case you are wondering how to study cell biology here are a few important cell biology topics that you should become familiar with.
Find out what is cell biology and genetics all about by joining our free live online classes. Also, access our latest PDF solutions of cell biology questions to improve your understanding of the concept and other related topics effectively. You can also download our app for enhanced accessibility to both study materials and interactive online sessions.