Plant and Animal Cells: Differences, Functions & Diagrams
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 –
Sex cell
Fat cell
Muscle cell
Bone cell
Immune cell
Blood cell
Epithelial cell
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
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.
Cell and tissue
Plant and animal cell
Cell wall and membrane
Cytoplasm
Cytoskeleton
Cell membrane and plasma membrane
Ribosome
Mitochondria
Chloroplast
Plastids
Centrosome
Vacuoles
Prokaryotic cell
Eukaryotic cell
Golgi apparatus
Endoplasmic reticulum
Microbodies
Nucleus
Unicellular organisms
Multicellular organisms
Cell division
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 Vedantu app for enhanced accessibility to both study materials and interactive online sessions.
FAQs on Cell Biology: Complete Guide for Students
1. What exactly is cell biology?
Cell biology is the branch of biology that focuses on studying cells. It explores the cell's structure, its many functions, how it behaves, and how cells interact with each other to form tissues and organisms.
2. What are the three main principles of the Cell Theory?
The Cell Theory, a fundamental concept in biology, is based on three main ideas:
- All living organisms are made up of one or more cells.
- The cell is the basic structural and functional unit of life.
- All cells arise from pre-existing cells through cell division.
3. What are the main differences between a plant cell and an animal cell?
While both are eukaryotic cells, there are a few key differences that are easy to remember:
- Cell Wall: Plant cells have a rigid cell wall outside the cell membrane for structural support, while animal cells do not.
- Chloroplasts: Plant cells contain chloroplasts to perform photosynthesis, which are absent in animal cells.
- Vacuole: Plant cells typically have one large central vacuole for storing water, whereas animal cells may have several small vacuoles.
4. What are prokaryotic and eukaryotic cells, and what is the main difference?
Prokaryotic and eukaryotic are the two major types of cells. The biggest difference is that a eukaryotic cell has a true, membrane-bound nucleus that holds its genetic material. A prokaryotic cell, like a bacterium, lacks a nucleus, and its genetic material floats freely in the cytoplasm.
5. What are the most important functions that a cell performs?
Every cell performs essential tasks to sustain life. Key functions include:
- Growth and Metabolism: Cells take in nutrients and convert them into energy to grow and function.
- Transport: They actively move necessary substances across their membranes.
- Reproduction: Cells divide to create new cells for an organism's growth or to reproduce.
- Response to Stimuli: They can sense and react to changes in their environment.
6. How is a cell often compared to a factory?
The "cell as a factory" analogy helps to understand how different organelles work together. In this comparison, the nucleus acts as the main office, giving instructions. The mitochondria are the power plants, generating energy. Ribosomes are the workers on the assembly line building proteins, and the Golgi apparatus is the packaging and shipping department.
7. Why are most cells microscopic and unable to be seen with the naked eye?
Cells remain tiny because they need to exchange nutrients and waste with their surroundings very efficiently. This efficiency depends on their surface-area-to-volume ratio. As a cell gets bigger, its internal volume increases much faster than its outer surface area. If a cell grew too large, its surface wouldn't be big enough to transport everything in and out quickly enough for it to survive.
8. How do different organelles within a cell work together to make a protein?
Making and moving a protein is a perfect example of teamwork inside the cell. First, the nucleus provides the instructions (in the form of mRNA). These instructions are then read by a ribosome, which builds the protein. The protein often moves to the endoplasmic reticulum for modification, and finally, the Golgi apparatus packages it for delivery to its final destination inside or outside the cell.
9. Why is studying cell biology important in our daily lives?
Understanding cell biology is crucial for many aspects of modern life. It helps us understand diseases like cancer, which is essentially a disease of uncontrolled cell division. This knowledge is also the foundation for developing new medicines and vaccines that target specific cellular processes to fight infections and illnesses.
