Cell - Structure, and Functions Class 8 Notes CBSE Science Chapter 8 (Free PDF Download)

Cell: 

• A cell is defined as the basic smallest structural and functional unit of an organism. They are complex units that are microscopic in nature.

• The term ‘cell’ was first coined by Robert Hooke in the year 1665 when he noticed boxes or compartments in a slice of cork under a microscope.

• An organism can be made up of a single cell unit and they are called unicellular organisms like an amoeba, paramecium, etc. 

• The single-cell unit of unicellular organisms performs all the functions necessary for life like growth, digestion, respiration, excretion, and reproduction by itself.

• An organism made up of many cells is called a multicellular organism like human beings, plants etc.

• In multicellular organisms, a group of special cells perform the same function and are termed tissues. Similar tissues form an organ and organs form an organism. Thus each cell or group of cells has a specific function to perform.

Flowchart of Organ System

• In general, the cells exhibit a wide variety of shapes, sizes, and numbers and these can vary from organism to organism.

• A cell can be as big as a hen’s egg which can be seen by the naked eye and as small as 0.1 - 0.5 micrometres in a bacteria. 

• A cell can be of multiple shapes. It can be spherical like the red blood cells or spindle-shaped like the muscle cells or branched like the nerve cells.

• The size of a cell is not related to the size of the organism, it is the function of that cell that is important. The nerve cells perform the same function of transferring messages whether it is in an elephant or a rat.

Parts of a Cell:

The cell has basically three main parts, which are the cell membrane, cytoplasm, and nucleus.

1. Cell membrane: This is the basic component of a cell that encloses the cytoplasm and nucleus and gives shape to the cell. This is also known as the plasma membrane and it separates the cells from each other. It is porous in nature to allow the transport of substances in and out of the cell. The plants have an additional thick outer layer known as the cell wall.

2. Cytoplasm: The jelly-like substance which is present between the cell membrane and the nucleus is called the cytoplasm. There are various other components of a cell that are present in the cytoplasm called organelles. They are as follows:

• Mitochondria

• Endoplasmic reticulum or the ER

• Ribosomes

• Lysosomes

• Vacuole

• Golgi body

• Plastids are small coloured bodies in the cytoplasm of plants. The green coloured ones are called chloroplasts.

• Centrosome which is present only in animal cells.

3. Nucleus: This is the dense spherical component that is present in the centre of the cell. This is the most important part of a living cell as it controls all the activities of the cell. It also contains thread-like structures called chromosomes which carry the hereditary material in the genes.

4. Nuclear membrane: The nucleus of a cell is separated from the cytoplasm by a porous membrane called a nuclear membrane which functions to transport substances between the cytoplasm and the nucleus.

5. Nucleolus: There are small spherical bodies present in the nucleus which are known as nucleolus.

Prokaryotic Cells:

The cells that lack a nuclear membrane for the nucleus are called prokaryotic cells, like bacteria and blue-green algae.

Eukaryotic Cells:

The cells that have a defined nuclear membrane for the nucleus are called eukaryotic cells. All organisms except bacteria and blue-green algae are eukaryotic cells. 

Comparison of Animal and Plant cell:

Plant Cell Diagram

Animal Cell Diagram

CBSE Class 8 Science Chapter 8 Revision Notes - Summary of the Chapter 

In the class 8th science chapter 8 notes, you will learn the basic functioning of the cell and how they are formed. Some of the basic features are listed below:

• Living organisms are made of cells, and different body parts are formed through a combination of cells. 

• Cells form all the parts of plants, including roots, stems, fruit, and leaves, formed with the cell combination. 

• Similarly, different organs in an animal are formed with cells. 

• No matter what is the shape of an organism, the basic functioning is of cells.

• Cells have different shapes and sizes and are different in unique organisms. 

• The shape of a cell is not fixed in unicellular organisms. One such example is Amoeba. 

How Cell Structure And Function Notes Class 8 Help To Prepare Well?

No doubt, students would have a basic understanding of cells, but the fact is, how will you answer them in the exams? Questions in the exams are not direct and basic. But it is up to your understanding and learning how to formulate and answer it correctly. It is better to answer a question to the point, and these class 8 ch 8 science notes help you prepare well as preferred during examinations.

During exams, it might not be easy to give a thorough reading of the chapter. Hence it would help if you learned the question wisely. 

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

The cell is the basic unit and is a vast topic to understand how living organisms are formed. There are different functioning, types, and sizes of cells in living organisms. Class eight is an essential phase of life to prepare well and maintain a good base for higher classes. Ch 8 science class 8 notes can help you understand the important topics that you need to study and prepare for your exam. Below are some listed topics that are covered in the notes:

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

Prokaryotic Cells and Eukaryotic Cells: These are the two basic types of cells present in the living organisms.

Cell Composition: It includes different parts of cells, including cell membrane, cytoplasm, nucleus, nuclear membrane, organelles, and basic other components. 

Plant Cells and Animal Cells: It includes how animal cells are different from plant cells.

Difference Between Plant Cells and Animal Cells: This is also a major concept covered that describes how plant cells and animals differ. 

Cell - Structure, and Functions Class 8 CBSE Science Chapter 8- Topics Covered 

Following 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

Cell - Structure, and Functions Class 8 CBSE Science Chapter 7 - Extra Questions to Practice (Solved)

1. Name the basic functional and structural unit of life.

Ans. The cell is known as the basic functional and structural unit of life. 

2. Why type of cell does not have a nucleus within it?

Ans. The RBC or Red Blood Cells do not have a nucleus within them. 

3. Name the parts of the Nucleus.

Ans. The parts of the nucleus are as follows:

The nuclear membrane, Nucleoplasm, and Nucleolus are the three parts of the nucleus. 

How to Study Science in Class 8 CBSE ? - Tips to Study Better 

Following are some suggestions and tips which are required in order to study your Science subject better:

1. Study the concept well and understand the core of it. 

2. Revise and take up tests regularly in order to excel in these subjects. 

3. The concepts which are very important must be practiced by writing them down.

4. Follow the NCERT Study Material to study the chapters of Science. 

Why are Revision Notes For Class 8 Chapter 8 - Cell Structure and Functions Important?

• Vedantu’s Revision Notes for Class 8 Chapter 8 - “Cell Structure and Functions” are the finest material to understand and practice the topics in the best way.

• The material carries all the information in detail and pointwise.

• All the cases of the material are solved in the simplest way which explains the term clearly.

• Vedantu Revision Notes for Class 8 Chapter 8 - Cell Structure and Functions provides all the main topics so that the student can focus on it and prepare for the exam. 

Conclusion 

By immersing yourself in the Class 8 Notes Chapter 8 Cell structure and Functions, you not only prepare for your exams more efficiently but also develop a profound understanding of the subject matter. The convenience of downloading these revision notes to your smart devices empowers you to study at your own pace, making learning more flexible and accessible. Vedantu, as a dedicated platform, aims to provide students with free CBSE Solutions (NCERT) and other essential study materials. Thus, the world of knowledge is at your fingertips, with the resources you need to excel in your academic journey.