Important MCQs on Cell Structure and Function for Class 9 Exams
Below are MCQ questions for class 9 biology, with answers covering the important topics from Class 9 Chapter 5 – The Fundamental Unit of Life. These questions will help you practise and prepare effectively for the fundamental unit of life class 9 MCQ online test and other examinations. Attempt these fundamental unit of life class 9 MCQ questions to strengthen your understanding of cells, their structure, and their functions.
1. Which of the following plastids are colourless?
A. Chromoplasts
B. Chloroplasts
C. Leucoplasts
D. All of the above
E. None of the above
Answer: C. Leucoplasts
Explanation: Plastids that do not contain any pigment are known as leucoplasts. Chromoplasts contain pigments other than green (often red, yellow, or orange), and chloroplasts contain the green pigment chlorophyll.
2. An unripe green fruit changes colour when it ripens. The reason is:
A. Chromoplasts change to chlorophyll
B. Chromoplasts change to chromosomes
C. Chromosomes change to chromoplasts
D. Chloroplasts change to chromoplasts
E. None of the above
Answer: D. Chloroplasts change to chromoplasts
Explanation: As fruits ripen, the green chloroplasts often get converted into coloured chromoplasts, which gives the fruit its characteristic ripe colour.
3. The phenomenon in which cytoplasm shrinks in a hypertonic medium is called:
A. Frontolysis
B. Plasmolysis
C. Acidolysis
D. Allolysis
E. None of the above
Answer: B. Plasmolysis
Explanation: In a hypertonic solution, water moves out of the cell due to osmosis, causing the cytoplasm and cell membrane to shrink away from the cell wall, a process known as plasmolysis.
4. ________ is called the energy currency of the cell.
A. Endoplasmic reticulum
B. Oxygen
C. ATP
D. Mitochondria
E. None of the above
Answer: C. ATP
Explanation: Adenosine Triphosphate (ATP) is a molecule that stores and provides energy for many biochemical processes in the cell.
5. ________ is called the powerhouse of the cell.
A. Mitochondria
B. ATP
C. Lysosomes
D. Red blood cells
E. None of the above
Answer: A. Mitochondria
Explanation: Mitochondria are responsible for producing most of the cell’s ATP through the process of cellular respiration, hence known as the powerhouse of the cell.
6. Who coined the term “cell”?
A. Gorbachev
B. Himmler
C. Robert Hooke
D. Antonie van Leeuwenhoek
E. None of the above
Answer: C. Robert Hooke
Explanation: Robert Hooke first observed and described cells in 1665 using a crude microscope. He used the term “cell” when he saw compartment-like structures in a slice of cork.
7. Which of the following statements is incorrect?
A. Cytoplasm is also known as protoplasm
B. Lysosomes are known as the suicide bags of the cell
C. Mitochondria have their DNA
D. All of the above is incorrect
E. None of the above
Answer: A. Cytoplasm is also known as protoplasm
Explanation: Protoplasm includes the cytoplasm and the nucleus. Cytoplasm alone is not referred to as protoplasm. Lysosomes are indeed called suicide bags, and mitochondria possess their DNA.
8. Which of the following is not a function of the vacuole in plants?
A. They store toxic metabolic wastes
B. They help with the process of cell division
C. They help to maintain turgidity
D. They provide structural support
E. None of the above
Answer: B. They help with the process of cell division
Explanation: Plant vacuoles primarily store substances (including waste) and help maintain cell turgidity and structural support. They are not directly responsible for cell division.
9. Where are the essential proteins and lipids required for the cell membrane manufactured?
A. Lysosome
B. Chromosomes
C. Endoplasmic reticulum
D. Mitochondria
E. None of the above
Answer: C. Endoplasmic reticulum
Explanation: The endoplasmic reticulum is involved in the synthesis of proteins (rough ER) and lipids (smooth ER), which are key components of cellular membranes.
10. The process by which water moves through a semi-permeable membrane from a region of higher concentration to a region of lower concentration, thus equalising water concentration, is called:
A. Evaporation
B. Diffusion
C. Osmosis
D. All of the above
E. None of the above
Answer: C. Osmosis
Explanation: Osmosis is a special type of diffusion involving water molecules moving across a semi-permeable membrane.
Additional Short Quiz (Try It Yourself)
Here are a few more of the fundamental unit of life class 9 MCQ questions to test your understanding. The answers are provided right after the questions so you can check and learn immediately.
Which of the following is not a cell organelle?
A. Ribosome
B. Cytoplasm
C. Golgi apparatus
D. Mitochondria
Answer: B. Cytoplasm (It is the fluid medium inside the cell, not considered a membrane-bound organelle.)
Which organelle is known for packaging and dispatching proteins?
A. Golgi apparatus
B. Ribosome
C. Nucleus
D. Endoplasmic reticulum
Answer: A. Golgi apparatus (It modifies, packages, and helps transport proteins to their destination.)
Which of these structures is absent in animal cells?
A. Cell wall
B. Nucleus
C. Cytoplasm
D. Cell membrane
Answer: A. Cell wall (Animal cells do not have a cell wall; it is characteristic of plant cells.)
Which of these is the site of photosynthesis in plant cells?
A. Endoplasmic reticulum
B. Chloroplast
C. Ribosome
D. Lysosome
Answer: B. Chloroplast (It contains chlorophyll for photosynthesis.)
This short quiz allows you to practise the fundamental unit of life class 9 MCQ online test-style questions and reinforce your learning.
Cells are the basic structural and functional units of life, often referred to as the fundamental unit of life. They vary in size, shape, and function but share common organelles such as the nucleus, cytoplasm, mitochondria, endoplasmic reticulum, Golgi apparatus, and others.
Plastids are found in plant cells (chloroplasts, chromoplasts, leucoplasts).
Mitochondria produce energy (ATP).
The endoplasmic reticulum is essential for protein and lipid synthesis.
Golgi apparatus modifies and packages proteins.
Lysosomes help in intracellular digestion.
Vacuoles maintain turgidity and store various substances in plant cells.
The cell membrane regulates the movement of substances in and out of the cell.
The cell wall (in plants) provides rigid support.
Understanding these core concepts will help you solve the fundamental unit of life class 9 MCQ questions and excel in exams.
Related Topics
FAQs on Class 9 Biology Chapter 5 The Fundamental Unit of Life MCQs
1. What is the fundamental unit of life in Class 9 Biology?
The cell is the fundamental unit of life because it is the smallest structural and functional unit of all living organisms. Every living organism is made up of one or more cells.
- The cell performs all basic life processes like nutrition, respiration, and reproduction.
- Unicellular organisms (like Amoeba) consist of a single cell.
- Multicellular organisms (like humans and plants) are made up of many specialized cells.
2. Who discovered the cell?
The cell was discovered by Robert Hooke in 1665 while observing cork under a microscope.
- He saw small box-like compartments and named them cells.
- Later, Antonie van Leeuwenhoek observed living cells for the first time.
- This discovery laid the foundation of cell biology.
3. What is cell theory in Chapter 5 The Fundamental Unit of Life?
The cell theory states that all living organisms are made of cells and that the cell is the basic unit of life.
- All plants and animals are composed of one or more cells.
- The cell is the structural and functional unit of life.
- All cells arise from pre-existing cells (proposed by Rudolf Virchow).
4. What is the difference between plant cell and animal cell?
The main difference between a plant cell and an animal cell is the presence of a cell wall and chloroplast in plant cells.
- Cell wall: Present in plant cells; absent in animal cells.
- Chloroplast: Present in plant cells for photosynthesis; absent in animal cells.
- Vacuole: Large central vacuole in plant cells; small or temporary vacuoles in animal cells.
- Shape: Plant cells are usually rectangular; animal cells are irregular or round.
5. What is the function of the cell membrane?
The cell membrane is a selectively permeable membrane that controls the movement of substances in and out of the cell.
- It allows useful substances like oxygen and nutrients to enter.
- It prevents harmful substances from entering.
- It maintains the internal environment of the cell.
6. What is the function of the nucleus in a cell?
The nucleus controls all activities of the cell and contains the genetic material.
- It contains DNA organized into chromosomes.
- It regulates cell growth and reproduction.
- It acts as the control center of the cell.
7. What is cytoplasm and what is its role?
The cytoplasm is a jelly-like substance present between the cell membrane and nucleus that holds cell organelles.
- It supports and suspends organelles like mitochondria and ribosomes.
- Most metabolic reactions occur in the cytoplasm.
- It helps in the transport of materials within the cell.
8. What is the function of mitochondria?
The mitochondria are known as the powerhouse of the cell because they produce energy in the form of ATP.
- They carry out cellular respiration.
- They release energy from food molecules.
- Cells that need more energy have more mitochondria.
9. What is osmosis in Class 9 Biology Chapter 5?
The osmosis is the movement of water molecules from a region of higher water concentration to lower water concentration through a selectively permeable membrane.
- It is a type of passive transport.
- It helps maintain cell shape and turgidity in plant cells.
- Example: Swelling of raisins when kept in water.
10. What are prokaryotic and eukaryotic cells?
The main difference between prokaryotic cells and eukaryotic cells is the presence of a true nucleus and membrane-bound organelles.
- Prokaryotic cells: No true nucleus; genetic material is free in the cytoplasm (e.g., bacteria).
- Eukaryotic cells: Have a well-defined nucleus and membrane-bound organelles (e.g., plants and animals).
- Eukaryotic cells are generally larger and more complex.
