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The Fundamental Unit of Life Class 9 Extra Questions and Answers Free PDF Download
When it comes to important questions for class 9 chapter 5, students can be confident that we have a very helpful collection of questions that will be extremely helpful when it comes to final exam preparation. Kids in class 9 will want a great deal of assistance with this chapter since it is really significant.
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With the help of the questions we have for them right here, they can actually have an insight into the chapter and hence will be able to understand the chapter in the best way. The Fundamental Unit of Life class 9 important questions from the chapter will provide the students with new confidence to crack their exams and score some good marks without any trouble or hassle. So, downloading these questions might be a great idea for the students. They can very easily ace their board exams and impress their teachers.
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CBSE Important Questions for Class 9 Science The Fundamental Unit of Life - 2025-26
ShareShareVery Short Answer Questions (1 Mark)
1. Can you name the two organelles we have studied that contain their own genetic material?
Ans: Chloroplast and Mitochondria.
2. Where are proteins synthesised inside the cell?
Ans: Inside the cell, ribosomes are the places where protein is synthesised.
Short Answer Questions (2 Marks)
1. Who discovered cells, and how?
Ans: Robert Hooke, an English scientist, discovered cells in 1665. While examining a tiny slice of cork under his self-designed microscope, he saw a honeycomb-like structure.
2. Why is the cell called the structural and functional unit of life?
Ans: Because all living organisms are made up of cells, the cell is the basic construction unit of a living organism, and all of a living organism's activities are the sum of activities conducted by its cells, the cell is referred to as the structural and functional unit of life.
3. Why is the plasma membrane called a selectively permeable membrane?
Ans: The plasma membrane is a very distinct structure. It is made up of lipids and proteins that selectively allow the entry of some molecules into the cell while preventing the exit of others, making it selectively permeable.
4. If the organisation of a cell is destroyed due to some physical or chemical influence, what will happen?
Ans: Because all of a cell's components are digested by its lysosomes, if the cell's organisation is damaged by some physical or chemical action, the cell will not survive.
5. Why are lysosomes known as suicide bags?
Ans: Lysosomes are organelles inside cells that contain hydrolytic (digestive) enzymes. When a cell is injured, its lysosomes may burst, allowing enzymes to digest the cell itself. As a result, we can call lysosomes "suicide bags."
6. What would happen if the plasma membrane ruptures or breaks down?
Ans: The rupture or breakdown of a cell's plasma membrane signals that the cell has been injured, and in this case, the damaged cell's lysosomes may burst, causing the digestive enzymes inside those lysosomes to eat their own cell. The cell will die as a result of this.
7. What would happen to the life of a cell if there was no Golgi apparatus?
Ans: The preservation, modification, and packaging of products in particles are all tasks of the Golgi apparatus. All types of storage, modification, packaging and dispatch of materials within and beyond the cell would be impossible if there was no Golgi apparatus for the cell.
8. Which organelle is known as the powerhouse of the cell? Why?
Ans: The cell's Mitochondria, also known as the cell's powerhouse, synthesises energy in the form of ATP during respiration, which is essential for many living processes.
9. Where do the lipids and proteins constituting the cell membrane get synthesised?
Ans: There are two types of endoplasmic reticulum:
(i). The smooth endoplasmic reticulum (SER) is in charge of producing the lipids that make up the cell membrane.
(ii). The ribosomes are housed in the rough endoplasmic reticulum (RER), which is responsible for the production of proteins that make up the cell membrane.
Short Answer Questions (3 Marks)
1. How do substances like \[C{{O}_{2}}\] and water move in and out of the cell? Discuss.
Ans: The exchange of gases $C{{O}_{2}}$ and ${{O}_{2}}$ between cells takes place by a diffusion process.
Diffusion is the migration of a chemical from a high-concentration region to a low-concentration zone. $C{{O}_{2}}$ is produced inside the cell as a result of respiration and accumulates in the cell, resulting in a high concentration of $C{{O}_{2}}$ in the cell compared to the outside environment. However, because ${{O}_{2}}$ is used inside the cell during respiration, its concentration declines inside the cell while remaining relatively high in the environment. As a result, $C{{O}_{2}}$ diffuses out of the cell and ${{O}_{2}}$ diffuses in.
2. Fill in the gaps in the following table illustrating the differences between prokaryotic and eukaryotic cells.
Ans: The difference between prokaryotic cell and eukaryotic cell as follows:
3. Make a comparison and write down ways in which plant cells are different from animal cells.
Ans: The difference between plant cells and animal cells is as follows:
4. How is a prokaryotic cell different from a eukaryotic cell?
Ans: The difference between prokaryotic cell and eukaryotic cell as follows:
5. How does an Amoeba obtain its food?
Ans: Amoeba feeds on planktonic bacteria that float in water. It grows artificial feet, or pseudopodia, to encircle the meal and then catches it in a sac-like structure called the food vacuole, within which food digestion occurs.
Process showing Amoeba obtaining its food
6. What is osmosis?
Ans: The passage of water (solvent) through a semipermeable membrane from a location of high-water concentration to a region of low water concentration is known as osmosis. It can only happen in a liquid medium; it cannot happen in solids or gases. Plant roots, for example, absorb water from the earth.
7. Carry out the following osmosis experiment:
Take four peeled potato halves and scoops each one out to make potato cups. One of these potato cups should be made from a boiled potato. Put each potato cup in a trough containing water. Now,
(a) Keep cup A empty
(b) Put one teaspoon sugar in cup B
(c) Put one teaspoon salt in cup C
(d) Put one teaspoon of sugar in the boiled potato cup D.
Keep these for two hours. Then observe the four potato cups and answer the following:
(i). Explain why water gathers in the hollowed portion of B and C.
Ans: When we add one teaspoon of sugar in cup B and one teaspoon salt in cup C, we create a hypertonic solution within, which allows water from outside to enter through osmosis and accumulate in the hollowed area of cups B and C.
(ii). Why is potato A necessary for this experiment?
Ans: To observe osmosis, you'll need Potato A.
(iii). Explain why water does not gather in the hollowed-out portions of A and D.
Ans: Because there is no solution (liquid medium) in the hollowed-out portions of A and D, osmosis cannot occur, and water does not collect.
CBSE Class 9 Science Chapter-5 Important Questions - Free PDF Download
Get Your Hands On The Fundamental Unit of Life Class 9 Important Questions From Us
Using the class 9 science chapter 5 extra questions, students can make sure that they can get some additional help when it comes to scoring some good marks in the examinations. There are many different topics and different sub-topics that are provided in the chapter. So, there is no doubt that the students need to download the class 9 science Ch 5 important questions. With the help of these questions, they will be able to understand some important topics. When it comes to the questions, students need to ensure that they have the PDF version or look for the questions online from the official site of Vedantu. These are some of the very best and the most important questions that will help them gain all the knowledge that they need in order to stay ahead of the class and gain some marks in the examination in the best way.
The topics which are covered in the chapter are about living organisms and so much more. Students get to familiar with concepts such as cells and the structural organization of the cells. There are some other important topics such as plasma membranes or cell membranes. Apart from that, some other important topics are covered in the chapter cell wall, cytoplasm, nucleus, and some cell organelles. There is no doubt that with these topics, students will get to dive deeper into the chapter and hence have some more insights as well. This will definitely help them in gaining some good marks in the examination in the best way without any trouble for sure. That is why we recommend you to download important questions of chapter 5 science class 9.
There are about 5 to 6 different exercises in the chapter which will give an idea of what to expect. With regular reading and thorough practice, students will be able to gain some knowledge about the chapter for sure. These are different questions in the exercises and hence the students need to make sure that they have an added information about the chapter for sure. This is one of the most important things that students need to keep in mind when they are downloading the important questions for class 9 science chapter 5.
How Are We Going To Help With Class 9 Science Chapter 5 Extra Questions
When it comes to the fundamental unit of life class 9 important questions, there is no doubt that Vedantu is one of the best places to have all the answers that you need. We have some very experienced teachers who are tasked with the opportunity to get the class 9 science chapter 5 extra questions to help the students out in the best way. All of these questions are targeted towards the CBSE syllabus and hence will help them score better marks in the examinations.
Conclusion
When it comes to chapter 5 questions for class 9, there is simply no doubt in my mind that these questions will cover all of the crucial themes in the greatest way possible. Additionally, the answers are included with the questions, and there is no doubt that having these questions will be quite beneficial.
Related Study Materials for CBSE Class 9 Science Chapter 5
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FAQs on CBSE Important Questions for Class 9 Science The Fundamental Unit of Life - 2025-26
1. What are the most important topics in CBSE Class 9 Science, Chapter 5 (The Fundamental Unit of Life) for the 2025-26 exams?
For the 2025-26 session, students should focus on these high-weightage topics from Chapter 5:
- The discovery of the cell and Cell Theory.
- The structural differences between prokaryotic and eukaryotic cells.
- Functions and structures of key cell organelles like the Nucleus, Mitochondria, Plastids, and Endoplasmic Reticulum.
- The processes of osmosis and diffusion across the plasma membrane.
- The stages and significance of Mitosis and Meiosis (Cell Division).
These topics frequently form the basis for 3-mark and 5-mark questions.
2. Why is the cell called the structural and functional unit of life?
The cell is called the structural unit because all living organisms are composed of one or more cells. It is called the functional unit because all essential life processes, such as respiration, digestion, and excretion, occur at the cellular level. Each cell can perform these basic functions independently, making it the fundamental building block of life.
3. What are the key differences between a prokaryotic and a eukaryotic cell?
The primary differences between prokaryotic and eukaryotic cells that are important for exams are:
- Nucleus: Eukaryotic cells have a well-defined, membrane-bound nucleus, while prokaryotic cells have an undefined nuclear region called a nucleoid, which lacks a nuclear membrane.
- Organelles: Eukaryotic cells contain membrane-bound organelles like mitochondria and Golgi apparatus. These are absent in prokaryotic cells.
- Chromosomes: Eukaryotic cells typically have more than one chromosome, whereas prokaryotic cells usually have a single, circular chromosome.
- Examples: Plants and animals are eukaryotes; bacteria are prokaryotes.
4. Which diagrams are important to practise from Chapter 5 for the Class 9 Science exam?
For scoring well in exams, it is crucial to practise drawing and labelling the following diagrams from 'The Fundamental Unit of Life':
- A detailed diagram of a plant cell.
- A detailed diagram of an animal cell.
- The structure of a eukaryotic nucleus.
- The structure of Mitochondria.
Ensure you can correctly label all the organelles as this is often a source of easy marks.
5. What would happen to the life of a cell if its plasma membrane ruptures?
If the plasma membrane of a cell ruptures, the cell would die. The plasma membrane is a selectively permeable barrier that controls the movement of substances in and out of the cell. Its rupture would lead to an uncontrolled exchange with the external environment, causing the essential cytoplasmic contents to leak out and harmful substances to enter, thereby disrupting all cellular functions.
6. Why are lysosomes known as 'suicide bags' of the cell?
Lysosomes are called 'suicide bags' because they contain powerful digestive enzymes. When a cell gets damaged, old, or diseased, the lysosomes may burst. The release of these enzymes into the cytoplasm digests the cell's own organelles and components, leading to the death of the cell. This process of self-digestion is known as autolysis and is a protective mechanism for the organism.
7. Explain why a plant cell can withstand greater changes in the surrounding medium than an animal cell.
A plant cell can tolerate greater changes in the external medium due to the presence of a rigid cell wall outside its plasma membrane. This cell wall is fully permeable and provides structural strength and support. In a hypotonic solution (dilute medium), an animal cell would swell and burst due to excessive water intake (osmosis). However, a plant cell will only swell up to a certain point, as the rigid cell wall exerts a counter-pressure, preventing it from bursting.
8. What are the expected types of questions from the 'Cell Division' topic for the 2025-26 exam?
From the 'Cell Division' section, you can expect questions worth 3 to 5 marks. Important question types include:
- Differentiating between Mitosis and Meiosis based on the number of daughter cells produced and the change in chromosome number.
- Explaining the significance of mitosis for growth and repair in organisms.
- Explaining the importance of meiosis in the formation of gametes for sexual reproduction.
- A HOTS (High Order Thinking Skills) question might ask about the consequences if meiosis did not reduce the chromosome number by half.
