9th Class Biology Chapter # 5 Exercise Solutions – Punjab Board
Tissues, Organs, and Organ Systems
9th Class Biology Chapter 5 Solution (MCQs)
1. A higher level of organization exhibits emergent properties when:
a) Its parts function independently
b) The sum of its parts is greater than the whole
c) The individual parts are more important than the whole
✅ d) Its parts interact to perform more functions
📝 Explanation: Emergent properties arise when all parts of a system work together to perform complex tasks that individual parts cannot perform alone.
2. Which of the following demonstrates the levels of organization of the body, from simplest to most complex?
a) Cell – Organ – Tissue – Organelle – Organ system
✅ b) Organelle – Cell – Tissue – Organ – Organ system
c) Tissue – Organelle – Organ – Cell – Organ system
d) Cell – Organelle – Organ system – Tissue – Organ
📝 Explanation: Biological organization increases in this order: Organelle → Cell → Tissue → Organ → Organ system.
3. At which level of organization gas exchange occurs between body and environment?
a) Organelle level in mitochondria
b) Cellular level in alveolar cells
c) Tissue level in epithelial tissues
✅ d) Organ system level in the respiratory system
📝 Explanation: Gas exchange (O₂ & CO₂) mainly occurs through the respiratory system, especially in lungs.
4. The epithelial tissue in the stomach wall is responsible for producing:
a) Mucus
b) Pepsinogen
c) Hydrochloric acid
✅ d) All of these
📝 Explanation: The stomach’s epithelial lining includes different cells producing mucus, enzymes like pepsinogen, and HCl.
5. In the wall of stomach, which tissue also contains blood vessels and nerves?
a) Epithelial
b) Muscle
✅ c) Inner connective
d) Outer connective
📝 Explanation: Connective tissue supports and binds other tissues and contains blood vessels and nerves.
6. In a leaf, which tissue is responsible for photosynthesis?
a) Xylem
✅ b) Mesophyll
c) Epidermis
d) Phloem
📝 Explanation: Mesophyll cells, especially palisade layer, are rich in chloroplasts and perform photosynthesis.
7. What is the primary function of spongy tissue in a leaf?
a) To transport sugars to other parts
b) To transport water to leaf
✅ c) To synthesize chlorophyll
d) To control the opening and closing of stomata
📝 Explanation: Spongy mesophyll contains chloroplasts and performs photosynthesis; it also aids in gas exchange.
8. Which of these is a function of the human skeletal system?
✅ a) Storing minerals and producing blood cells
b) Removing carbon dioxide from blood
c) Filtering blood to remove waste products
d) Breaking down food for energy
📝 Explanation: Skeletal system supports the body, stores calcium, and produces blood cells in bone marrow.
9. Which structures are responsible for the transport of food in plant body?
a) Xylem tissue
b) Palisade mesophyll
✅ c) Phloem tissue
d) Spongy mesophyll
📝 Explanation: Phloem transports glucose and other food materials from leaves to rest of the plant.
10. In a plant, which of the following is the primary function of the flower?
a) Transporting water and minerals
b) Supporting leaf growth
✅ c) Facilitating reproduction through pollination
d) Regulating gas exchange
📝 Explanation: Flowers help in reproduction through pollination, leading to formation of fruits and seeds.
9th Class Biology Chapter 5 Solution Mcqs Complete.
9th Class Biology Chapter 5 Solution Short Answer Questions
1. Enlist the levels of organization from cells to organ systems.
✅ Answer:
Cell → Tissue → Organ → Organ System → Organism
2. What are the major roles of the epithelial tissue present in the stomach?
✅ Answer:
Secretes mucus to protect stomach lining
Produces digestive enzymes and hydrochloric acid
Absorbs nutrients and water
3. How do the smooth muscles contribute to the stomach’s function?
✅ Answer:
Smooth muscles help in mixing and pushing food (peristalsis), aiding digestion by contracting rhythmically.
4. What is the function of the palisade mesophyll in the leaf?
✅ Answer:
Performs photosynthesis due to presence of chloroplasts; it absorbs sunlight effectively.
5. What is the role of the shoot system in plants?
✅ Answer:
Supports the plant above ground
Performs photosynthesis (leaves)
Bears flowers for reproduction
Transports water and food
6. What is homeostasis, and why is it important for organisms?
✅ Answer:
Homeostasis is the maintenance of a stable internal environment. It is essential for survival and proper functioning of cells and organs.
7. How does the human body maintain a stable internal temperature?
✅ Answer:
Through thermoregulation – e.g., sweating to cool down, shivering to generate heat, and blood flow regulation by the skin.
8. Differentiate between the following:
i. Tissue and organ
Tissue: Group of similar cells performing a function.
Organ: Structure made of different tissues working together.
ii. Root system and shoot system
Root system: Below ground, anchors plant and absorbs water/minerals.
Shoot system: Above ground, supports, photosynthesizes, and reproduces.
iii. Epidermal and mesophyll tissue
Epidermal: Outer protective layer of leaf.
Mesophyll: Inner tissue that performs photosynthesis.
iv. Palisade and spongy mesophyll
Palisade mesophyll: Tightly packed cells, rich in chloroplasts, absorb light.
Spongy mesophyll: Loosely arranged cells, allow gas exchange.
- 9th Class Biology Chapter 5 Solution Short Question Complete.
9th Class Biology Chapter 5 Solution in Detail
1. Explain the levels of organization in multicellular organism. How does each level contribute to the overall function of an organism?
✅ Answer:
Cell: Basic unit of life (e.g., muscle cell)
Tissue: Group of similar cells (e.g., muscle tissue)
Organ: Structure made of different tissues (e.g., heart)
Organ system: Group of organs performing a function (e.g., circulatory system)
Organism: A complete living individual.
Each level builds upon the previous one to ensure proper growth, function, and survival.
2. What is a tissue level? Explain the major tissues.
✅ Answer:
Tissue level is the second level of organization where similar cells perform a specific function.
Major tissues:
Epithelial tissue: Covers body surfaces and lines organs.
Connective tissue: Supports and binds tissues (e.g., blood, bone).
Muscle tissue: Causes movement.
Nervous tissue: Transmits nerve impulses.
3. Describe the tissue composition of the stomach. How does each tissue contribute to digestion?
✅ Answer:
Epithelial tissue: Secretes digestive enzymes and acid, protects inner lining.
Muscle tissue: Performs mixing of food by contraction (peristalsis).
Connective tissue: Supports and binds other tissues; contains blood vessels and nerves.
Nervous tissue: Controls contractions and secretions.
4. Describe the tissue composition of the leaf. How does each tissue contribute to the function of the leaf?
✅ Answer:
Epidermal tissue: Protective outer layer, reduces water loss.
Mesophyll tissue: Contains palisade (photosynthesis) and spongy cells (gas exchange).
Vascular tissue: Xylem transports water, phloem transports food.
5. How do the organ systems come together to form the human body?
✅ Answer:
Different organ systems like digestive, circulatory, respiratory, nervous, etc., work together to perform complex life functions.
They are interdependent and coordinate to maintain the survival and balance of the body.
6. Describe the role of the digestive system and the excretory system in homeostasis.
✅ Answer:
Digestive system: Breaks down food into nutrients; provides energy.
Excretory system: Removes waste materials like urea and maintains water and salt balance.
Both systems maintain internal balance and prevent toxic buildup.
7. Explain the functions of various plant organs.
✅ Answer:
Root: Anchors plant, absorbs water and minerals.
Stem: Supports plant, transports substances.
Leaves: Perform photosynthesis and gas exchange.
Flower: Reproduction.
Fruit: Protects seeds and helps in seed dispersal.
8. Describe the structure and function of the plant root system.
✅ Answer:
Structure: Tap root or fibrous roots with root hairs.
Function: Anchors the plant, absorbs water and minerals, and stores food.
9. Define homeostasis and explain its importance. Discuss how different organ systems work together to maintain homeostasis.
✅ Answer:
Homeostasis is the maintenance of a constant internal environment.
It is essential for cell function and survival.
Examples:
Nervous + Endocrine systems regulate body temperature and glucose.
Excretory + Respiratory systems remove wastes and maintain pH.
All systems cooperate to maintain stable internal conditions.
10. Describe how the respiratory and circulatory systems work together to maintain homeostasis of oxygen and carbon dioxide levels.
✅ Answer:
Respiratory system brings in oxygen and removes carbon dioxide.
Circulatory system transports oxygen to cells and brings CO₂ back to lungs.
This coordination ensures stable oxygen and pH levels, maintaining homeostasis.- 9th Class Biology Chapter 5 Solution Details Complete.
9th Class Biology Chapter 5 Solution Inquisitive Questions
1. How does the structure of epithelial tissue relate to its function in different parts of the body?
✅ Detailed Answer:
Epithelial tissue is a specialized tissue that covers the body surfaces, lines internal organs, and forms glands. Its structure is highly adapted to suit its functions, which include protection, absorption, filtration, and secretion. The type and arrangement of epithelial cells vary depending on the role it plays in a specific organ or body part:
Simple Squamous Epithelium:
These are flat and thin cells, ideal for diffusion and filtration. They are found in alveoli of lungs, where gases like oxygen and carbon dioxide diffuse across cell membranes quickly, and in capillaries, where exchange of materials occurs.Simple Columnar Epithelium:
These tall, rectangular cells are found in the lining of the small intestine. Their structure allows for maximum absorption of nutrients, and they often contain microvilli to increase surface area. Some also secrete mucus and enzymes.Ciliated Epithelium:
Found in the trachea and fallopian tubes, these cells have hair-like projections called cilia that help move mucus or eggs. In the trachea, cilia move dust particles and mucus out of the respiratory tract.Stratified Squamous Epithelium:
Composed of multiple layers, it provides protection in areas exposed to friction, such as skin, mouth, and esophagus.Cuboidal Epithelium:
Cube-shaped cells found in glands and kidney tubules, where they help in secretion and absorption.
🔹 In summary, the structural adaptations of epithelial tissue — including cell shape, number of layers, and presence of special features like cilia or microvilli — directly relate to their specific functions in the body.
2. Evaluate the importance of organ systems working in harmony and predict the consequences of a failure in one system on the others.
✅ Detailed Answer:
The human body is organized into interconnected organ systems, each responsible for specific tasks, but all working together to maintain homeostasis and overall health. The proper functioning of one system often depends on the health and efficiency of others. This interdependence ensures survival and efficient operation of the body.
🔸 Importance of Harmony:
The digestive system breaks down food into nutrients.
The circulatory system transports these nutrients to all body cells.
The respiratory system provides oxygen needed by cells to extract energy from nutrients.
The excretory system removes waste products from metabolism.
The nervous and endocrine systems regulate and coordinate the functioning of all others.
If one system fails, it creates a domino effect, impacting several others. For example:
🔹 Examples of System Failure and Impact:
Failure of the Respiratory System:
Reduced oxygen supply → affects the circulatory system (less oxygen to transport) → leads to muscle fatigue (muscular system) → impairs brain function (nervous system).Failure of the Kidneys (Excretory System):
Buildup of toxins → disturbs nervous system (confusion, seizures), digestive system (nausea, vomiting), and cardiovascular system (increased blood pressure due to fluid retention).Endocrine Disorders (e.g., Diabetes):
Imbalance in blood sugar regulation → affects circulatory system (damaged blood vessels), nervous system (neuropathy), excretory system (kidney damage), and immune system (increased infections).
🔹 Therefore, coordination between organ systems is not just important—it is critical for survival. A breakdown in one system can lead to serious complications in others, ultimately threatening the health or life of the organism.
9th Class Biology Chapter 5 Solution Inquisitive question Complete.
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