Class 9th · Biology · Chapter 5
Chapter 5: Tissues, Organs, and Organ Systems
Chapter 5 of the Punjab Board Class 9th Biology textbook runs from page 79 to 92 and covers 4 topics. Its exercise has exercise, multiple choice questions, short / constructed response questions, comprehensive questions and conceptual questions. Open any of those pages in GenZ Books, tap a question, and the answer is worked from this chapter.
Open Chapter 5 of Biology in GenZ Books
The same Class 9th textbook, page for page. Tap any question and get the answer worked from that chapter — English and Urdu.
Topics in this chapter
- 5.1Levels of Organizationp. 79
- 5.2Organs and Organ Systems in Plantsp. 82
- 5.3Organs and Organ Systems in Humansp. 85
- 5.4Homeostasisp. 87
Exercise
- Exercisep. 90
- Multiple Choice Questionsp. 90
- Short / Constructed Response Questionsp. 92
- Comprehensive Questionsp. 92
- Conceptual Questionsp. 92
A sample answer from GenZ Books
Solve · page 92: 2. Evaluate the importance of organ systems working in harmony and predict the consequences of a failure in one system on the others. NOT FOR SALE-PESRP 92
Organ systems must work in harmony; failure of one system adversely affects the others, leading to overall dysfunction.
- Why harmony is important
- Each system provides essential substances or conditions for another (e.g., the respiratory system supplies oxygen to the circulatory system, which transports it to all cells).
- Coordination maintains homeostasis – stable internal environment required for life.
- Examples of inter‑dependence
- Digestive system → nutrients → circulatory system → delivery to tissues.
- Excretory system → removal of waste → protects cells of all other systems.
- Nervous system → controls muscle activity, gland secretion, and heart rate, influencing muscular, endocrine, and circulatory systems.
- Consequences of failure in one system
- Circulatory failure → reduced oxygen and nutrient supply → respiratory distress, muscle fatigue, brain dysfunction.
- Respiratory failure → low oxygen → heart works harder, waste (CO₂) builds up, affecting nervous and muscular systems.
- Digestive failure → lack of nutrients → weakened immune response, poor growth, and impaired repair of tissues in all systems.
- Excretory failure → accumulation of toxic waste → damage to kidney, heart, and nervous tissues.
- Overall impact
- Disruption in one system creates a chain reaction, compromising the performance of multiple systems and ultimately threatening the organism’s survival.
Check: Verify by tracing how a product of one system (e.g., oxygen from lungs) is used by another (e.g., blood cells) and see what happens when that supply stops.
AI-generated from the chapter text by GenZ Books. It can make mistakes — check it against your textbook and your teacher.