Cell is a basic and functional unit of living things.


1- Short Defined

Animal Cell:

- round in shape 

- contains a cell membrane, cytoplasm, nucleus, and organelles such as mitochondria, ribosomes, and lysosomes 

- does not have a cell wall 

- lacks chloroplasts and can therefore not undergo photosynthesis 

- usually exists as an individual cell but can form tissues and organs in some organisms 


Plant Cell:

- rectangular in shape 

- contains a cell membrane, cytoplasm, nucleus, and organelles such as mitochondria, ribosomes, and lysosomes 

- has a cell wall made of cellulose and hemicellulose for extra support and rigidity 

- contains chloroplasts, which allow the plant to undergo photosynthesis and produce glucose and oxygen 

- has larger vacuoles for storing water and other nutrients 

- can form tissues and organs in some organisms, but are usually rigid and tightly organized in a grid-like pattern due to the cell wall

2- Long Defined

a) Animal Cell

An animal cell is a basic unit of life found in animals. These cells must function properly in order for animal organisms to maintain homeostasis and survive. In this article, we will explore the structure and function of animal cells and the organelles within them.

The basic structure of an animal cell can be divided into three parts: the cell membrane, the cytoplasm, and the nucleus. The cell membrane is a thin layer that separates the cell from its surrounding environment. It controls the entry and exit of substances, including nutrients and wastes. The cytoplasm is a jelly-like substance that fills the cell and contains most of its organelles. The nucleus is the control center of the cell and contains the genetic material DNA.

One of the most important organelles in animal cells is the mitochondria. These organelles are responsible for producing energy for the cell through a process called cellular respiration. During this process, glucose is broken down into energy that the cell can use. Mitochondria have their own DNA and can reproduce independently of the rest of the cell.


Another important organelle in animal cells is the endoplasmic reticulum (ER). The ER is a network of tubes and sacs that transports materials throughout the cell. There are two types of ER: rough ER and smooth ER. Rough ER is covered in ribosomes, which give it a bumpy appearance. The ribosomes are responsible for producing proteins, which are then transported throughout the ER and on to other parts of the cell. Smooth ER, on the other hand, does not have ribosomes and is responsible for producing lipids and detoxifying harmful substances.


Ribosomes are also found in animal cells. These small organelles are responsible for synthesizing proteins. They can be found floating freely in the cytoplasm or attached to the rough ER.

Lysosomes are organelles that play an important role in breaking down and recycling materials in the cell. They contain enzymes that break down old and worn out organelles and other cellular debris. This process is called autophagy.

Animal cells also contain a cytoskeleton, which is a network of protein fibers that gives the cell structure and helps it maintain its shape. The cytoskeleton is made up of three types of fibers: microfilaments, intermediate filaments, and microtubules. These fibers also help the cell move and perform other functions.

Finally, animal cells contain centrosomes, which are made up of two centrioles. Centrosomes help to organize the cell’s microtubules during cell division.

In summary, animal cells are complex structures made up of various organelles that work together to maintain the cell’s function. The mitochondria produce energy, the ER transports materials, the ribosomes synthesize proteins, the lysosomes break down waste, and the cytoskeleton gives the cell structure. The nucleus controls all of these processes and contains the cell’s genetic material.

Animal cells are not limited to one type. Different animal cells have unique structures and functions that help to ensure the specialized functions of the organs in which they exist. For instance, muscle cells have the ability to contract and relax, so they have many mitochondria to produce energy. Additionally, nerve cells conduct electrical impulses, so they have long thread-like extensions called axons to transmit signals.

One of the most important aspects of animal cells is their ability to communicate with one another. In order for an organism to function properly, cells must be able to communicate with each other to coordinate their activities. This is done through various signaling pathways in which cells release and respond to specific molecules called signals. Signals can be in the form of hormones, neurotransmitters, growth factors, or other molecules.

An example of cell communication can be found in the immune system. Immune cells use signals to communicate with each other to identify and destroy infectious agents. Without proper communication, the immune system would not be able to function.

The study of animal cells is not a recent phenomenon. Robert Hooke first observed and described cells in the 17th century, and Antonie van Leeuwenhoek was the first to observe living cells in the 18th century. Since then, technology has advanced, allowing scientists to explore and understand animal cells in greater detail.

In conclusion, animal cells are complex structures that are made up of many different organelles that work together to maintain the cell’s function. The mitochondria produce energy, the ER transports materials, the ribosomes synthesize proteins, the lysosomes break down waste, and the cytoskeleton gives the cell structure. The nucleus controls all of these processes and contains the cell’s genetic material. Different animal cells have unique structures and functions that help to ensure their specialized roles in the organs in which they exist. Cell communication is also an important aspect of animal cells, as it allows the cells to coordinate their activities to maintain homeostasis and ensure the proper functioning of the organism as a whole.


b) Plant Cell

Plant cells are the basic structural and functional units of all plants. These cells are highly complex and specialized, containing a variety of organelles and structures that work together to support the plant's life processes. In this article, we will explore the different parts of a plant cell and their functions.


Cell Wall:
One of the most distinctive features of plant cells is their cell walls. The cell walls are made of cellulose, which is a complex carbohydrate that provides structural support to the cell. These walls are thick and rigid, giving the plant its shape and allowing it to defend against external environmental stresses, such as wind and water.

Cell Membrane:
The cell membrane is a thin layer of lipid and protein molecules that surrounds the cell. This membrane controls the movement of substances in and out of the cell, regulating its chemical composition and electrical charge. It gives the cell some degree of flexibility, allowing it to expand and contract as needed.

Nucleus:
The nucleus is the control center of the cell. It contains the cell's genetic material, including the DNA that carries the instructions for the plant's growth, development and reproduction. The nucleus directs the cellular processes, regulating the expression of specific genes and controlling the production of proteins and enzymes.

Chloroplasts:
Chloroplasts are specialized plant organelles responsible for photosynthesis. They are found in the cells of leaves, stems and other green organs. The chloroplasts contain the pigments chlorophyll and carotenoids, which capture light energy from the sun and use it to produce glucose and oxygen from carbon dioxide and water.

Mitochondria:
Mitochondria are the energy-generating organelles of the cell. They take in glucose and oxygen and use them to produce cellular energy in the form of ATP. This energy is used by the cell for various cellular functions such as growth, division, and repair.

Endoplasmic Reticulum:
The endoplasmic reticulum (ER) is a complex network of membranous channels and tubules that extends throughout the cell. It is responsible for protein synthesis and sorting, and plays a role in lipid metabolism, calcium signaling, and other cellular functions.

Ribosomes:
Ribosomes are the sites where protein synthesis occurs. They are found either in the cytoplasm or on the surface of the endoplasmic reticulum. Ribosomes read the genetic code from the DNA and use it to assemble proteins, the building blocks of the plant's cellular structures and processes.

Golgi Apparatus:
The Golgi apparatus is another organelle involved in protein sorting and secretion. It receives proteins from the ER and packages them into secretory vesicles. These vesicles are then transported to the cell membrane for exocytosis, or released into the extracellular space.

Vacuoles:
Vacuoles are fluid-filled sacs that store water, nutrients, and other substances. They are particularly important for maintaining water balance in plant cells, helping the cell to retain its turgor pressure and avoid dehydration.

In conclusion, plant cells are highly specialized and complex structures, consisting of a variety of organelles and structures that work together to support the plant's life processes. Although they are similar to animal cells in their basic structure, the presence of cell walls, chloroplasts and large vacuoles sets them apart. Understanding the functions of each of these parts is critical to understanding how plants grow, develop, and respond to environmental stresses.