CBSE Class 8 Science Revision Notes Chapter 8

CBSE Class 8 Science Revision Notes Chapter 8 – Cell – Structure and Functions

Extramarks Class 8 Science Chapter 8 Notes is a great resource for a quick review of the chapter Cell Structure and Function. The cell is the fundamental structural unit of all living things, whether they be plants or animals. After reading the notes, students will have a basic understanding of cell structure and function. These notes will give an edge to students’ preparation by helping them master the chapter’s content with key points. 

The complete notes for Class 8 Science Chapter 8 will help students thoroughly review the entire chapter. These Chapter 8 Science Class 8 Notes were developed by subject matter experts considering the revised CBSE guidelines and syllabus. Students can entirely focus on their academics with these precise and high-quality notes.

The Class 8 Science Chapter 8 Notes can help students quickly review extensive chapters for the exam in a limited time.

Revision Notes for CBSE Class 8 Science Chapter 8

Access Class 8 Science Chapter 8 – Cell — Structure and Functions Notes


  • The simplest, smallest structural and functional unit of an organism is called a cell. These intricate, microscopic structures are of a complex nature.
  • Robert Hooke first used the word “cell” in 1665 after spotting boxes or compartments in a piece of cork under a microscope.
  • Organisms with only one cell unit, such as amoebas, parameciums, etc., are referred to as unicellular organisms.
  • One cell that is capable of performing all of life’s main functions, such as growth, digestion, respiration, excretion, and reproduction, makes up a unicellular creature.
  • A multicellular organism is one that consists of many cells, such as humans, plants, and other living things.
  • Tissues are collections of special cells that share a common function in multicellular organisms. Organs are made of similar tissues, and organisms are made of organs. As a result, each cell or group of cells has a particular job to do.
  • In general, there are significant differences between organisms in the types, quantities, and forms of the cells.
  • A cell can be as little as 0.1 to 0.5 micrometres in a bacterium and as huge as a hen’s egg.
  • A cell can take on a variety of forms. It can be spherical, like red blood cells, or have a shape resembling a spindle or branch, like muscle or nerve cells.
  • The importance of a cell’s function exceeds its physical dimensions, which do not influence the size of the organism. Whether found in an elephant or a rat, nerve cells have the same ability to transmit messages.

Parts of a Cell:

The cell membrane, cytoplasm, and nucleus make up the cell’s basic three constituent parts.

Cell membrane

This is the fundamental part of a cell that gives the cell its shape and encloses the cytoplasm and nucleus. The plasma membrane, which separates cells from one another, is another name for this structure. Its porous nature enables the movement of materials into and out of the cell. The cell wall is a thicker outer layer that is present in plants.


The cytoplasm is the jelly-like material that lies in the space between a cell’s membrane and its nucleus. Organelles are a general term for a variety of additional cell components that are found in the cytoplasm. These are what they are:

  • Centrosome (present only in animal cells)
  • Endoplasmic reticulum or the ER
  • Golgi body
  • Lysosomes
  • Mitochondria
  • Plant cytoplasm contains tiny coloured structures called plastids. The chloroplasts are the ones that are green.
  • Ribosomes
  • Vacuole


This is the dense, spherical element that makes up the cell’s centre. A nucleus is the most crucial component of a living cell because it regulates all the functions of the cell. It also has chromosomes, thread-like structures that transport the genetic material.

Nuclear membrane

It is a porous membrane that serves to transport substances between the cytoplasm and the nucleus and separates the nucleus of a cell from the cytoplasm.


The nucleus contains little spherical structures known as nucleoli.

Prokaryotic Cells:

Prokaryotic cells, which include bacteria and blue-green algae, are those that do not have a nuclear membrane around the nucleus.

Eukaryotic Cells:

Eukaryotic cells are those that have a distinct nuclear membrane around the nucleus. Eukaryotic cells are found in most organisms, except in bacteria and blue-green algae.

Comparison of Animal and Plant cells:

Component Animal Cell Plant Cell
Cell Membrane Present  Present 
Cell Wall  Absent  Present 
Cytoplasm Present  Present 
Nucleus  Present  Present 
Nuclear membrane Present  Present 
Plastids  Absent  Present 
Vacuole  Present  Present 

CBSE Class 8 Science Chapter 8 Revision Notes

In Class 8 Science Chapter 8 Notes, the basic traits of a cell and how they are formed will be explained. Here are some of the fundamental characteristics:

  • Cells make up living things, and the fusion of different cell types creates different body parts.
  • All the components of a plant, such as the roots, stems, fruit, and leaves, are made up of cells.
  • Similar processes occur when different animal organs are formed.
  • Cells are responsible for an organism’s core function, regardless of its structure.
  • Unique organisms have different cells with various shapes, sizes, and compositions.
  • Unicellular organisms do not have fixed cell shapes. For example, amoeba.

Cell Structure and Functioning Explained in Science Class 8 Chapter 8 Notes

Students have learnt the fundamental functioning of cells in earlier classes. Chapter 8 of Class 8 Science will cover cells and their related topics in further detail. For this, students must conceptually understand the chapter to better answer the questions asked in the exam. These Class 8 Science Notes Chapter 8 will help students adequately prepare for exams.

These revision notes supplement a thorough reading of the chapter. Especially before an exam, it is advised that students carefully study the important points discussed in these notes.

How Cell Structure and Function Notes Class 8 Help to Prepare Well?

The cell is a huge topic and is the basic building unit of all living things. Different cell kinds, sizes, and functions can be found in living things. Students can understand these crucial topics by referring to the Class 8 Science Notes Chapter 8 and preparing for their tests. The following are some of the main topics covered in the notes:

World of Cells: It discusses the different types of cells with their functioning.

Prokaryotic Cells and Eukaryotic Cells: The two fundamental cell types found in all living things are prokaryotic and eukaryotic.

Cell Composition: It contains many cell components, such as the cell membrane, cytoplasm, nucleus, nuclear membrane, organelles, and other fundamental sections.

Plant and Animal Cells: It discusses the distinctions between animal and plant cells.

Difference Between Plant Cells and Animal Cells: This is another key idea that explains how plant and animal cells differ from one another.

What Are the Subtopics Covered in Notes of Chapter 8 Class 8 Science?

Here are the topics that are covered in this chapter:

  • Discovery of the Cell
  • The Cell
  • Organisms Show Variety in Cell Number, Shape, and Size
  • Number of Cells
  • Shape of Cells
  • Size of Cells
  • Cell Structure and Function
  • Parts of the Cell
  • Comparison of Plant and Animal Cells

How Can You Prepare Well for Exams?

Students need to focus on not just memorising key concepts but also learning them well enough to answer their tests. Class 8 Science Notes Chapter 8 will undoubtedly assist students in understanding terms and scoring higher marks.

FAQs (Frequently Asked Questions)

1. What are the postulates of cell theory?

According to the postulates covered in the Class 8 Chapter 8 Notes of the cell theory, the cell is the fundamental functional unit. Cells are made from old cells through cell division, and all activity carried out by an organism is performed by its cells. These are all the fundamental tenets of cells. 


2. What is the basic functioning of cells?

The nucleus within the cell is responsible for the cell’s fundamental functionality. It resembles a control centre that oversees the body’s operations. Additionally, a cell is solely in charge of the body’s development, growth, and cell division. The nucleus, where the DNA is located, is in charge of creating proteins. Only energy production, metabolic reactions, and active and passive transportation are its responsibilities. Consequently, a cell is a living organism’s building block.

3. According to Chapter 8 of Class 8 Science, what are eukaryotes?

Organisms called eukaryotes to have one or more cells. The opposite of prokaryotes is eukaryotes. Chromosome formation is aided by these. They typically have multiple cells. Because eukaryotes have a nuclear membrane, the nucleus is more defined. Eukaryotes are cells with a nuclear membrane and a well-organised nucleus. Eukaryotes additionally possess all other cell organelles. Animal cells, plant cells, fungi, cheek cells, onion cells, and more are a few examples of eukaryotes.


4. According to Chapter 8 of Class 8 Science, what are prokaryotes?

Prokaryotes are organisms with only one cell. They are of a single-cell type. Nucleolar membranes are absent in prokaryotes. As a result, the cell’s nucleus is not clearly defined. The nucleolus is absent in prokaryotes because the nucleus is improperly defined. In addition, not all cell organelles are present in prokaryotes. Prokaryotes are, therefore, defined as cells that contain nuclear material but lack a nuclear membrane. Prokaryotes include various organisms like bacteria and blue-green algae.