Introduction
Long questions are an essential part of Biology examinations for both Class 9 and Class 10. These questions test a student’s ability to explain concepts in detail, describe biological processes, and apply knowledge logically.
This page provides important long questions with structured answers from the Class 9 and Class 10 Biology syllabus. Practicing these questions helps students improve writing skills, understand concepts deeply, and perform better in written examinations.
Long Questions Practice – Biology
1. Describe the structure and functions of a cell.
A cell is the basic structural and functional unit of life. All living organisms are made up of one or more cells. Cells vary in shape and size depending on their function.
The main parts of a typical cell include the cell membrane, cytoplasm, and nucleus. The cell membrane controls the movement of substances into and out of the cell. The cytoplasm contains cell organelles and is the site of many metabolic activities. The nucleus controls all cellular activities and stores genetic material in the form of DNA.
Cells perform essential functions such as growth, respiration, reproduction, and response to stimuli. In multicellular organisms, specialized cells work together to form tissues and organs.
2. Explain the role of enzymes in biological reactions.
Enzymes are biological catalysts that speed up chemical reactions in living organisms. They are mostly proteins and are highly specific in their action.
Each enzyme has an active site where the substrate binds. The enzyme-substrate complex forms, allowing the reaction to occur more quickly by lowering activation energy. After the reaction, the enzyme remains unchanged and can be reused.
Enzyme activity is affected by factors such as temperature, pH, and substrate concentration. Extremely high temperatures or unsuitable pH can denature enzymes and stop their activity. Enzymes are essential for digestion, respiration, and other metabolic processes.
3. Describe photosynthesis and explain its importance.
Photosynthesis is the process by which green plants manufacture food using carbon dioxide, water, and sunlight in the presence of chlorophyll.
During photosynthesis, light energy is converted into chemical energy stored in glucose. Oxygen is released as a byproduct. This process mainly occurs in the leaves of plants.
Photosynthesis is important because it is the primary source of food and energy for all living organisms. It maintains the balance of oxygen and carbon dioxide in the atmosphere and forms the basis of all food chains.
4. Explain cellular respiration and its types.
Cellular respiration is the process by which cells release energy from food substances, mainly glucose. This energy is used for growth, movement, and maintenance of life processes.
There are two types of respiration:
- Aerobic respiration, which occurs in the presence of oxygen and produces carbon dioxide, water, and a large amount of ATP.
- Anaerobic respiration, which occurs in the absence of oxygen and produces less energy along with byproducts such as lactic acid or alcohol.
Respiration is essential because it supplies energy required for all cellular activities.
5. Describe the process of inheritance.
Inheritance is the transmission of genetic characteristics from parents to offspring. It occurs through genes located on chromosomes.
Genes exist in pairs called alleles. One allele may be dominant while the other is recessive. Dominant traits appear even if only one dominant allele is present, whereas recessive traits appear only when both alleles are recessive.
Gregor Mendel explained inheritance through experiments on pea plants and proposed laws such as the law of segregation and law of dominance. Inheritance causes variation, which plays an important role in evolution.
6. Explain the role of biotechnology in medicine.
Biotechnology uses living organisms or their products to develop useful substances. In medicine, biotechnology has greatly improved diagnosis and treatment of diseases.
Products such as recombinant insulin, vaccines, antibiotics, and hormones are produced using biotechnology. Genetic engineering allows bacteria to produce human insulin for diabetic patients.
Biotechnology is also used in gene therapy, diagnostic tests, and development of vaccines. It has made medical treatments safer, more effective, and widely available.
7. Describe drug addiction and its effects on human health.
Drug addiction is a condition in which a person becomes physically or mentally dependent on drugs. Addictive drugs affect the nervous system and alter brain function.
Drug addiction can cause serious health problems such as liver damage, heart disease, mental disorders, and weakened immunity. It also leads to social problems including crime, family breakdown, and financial loss.
Prevention of drug addiction requires education, awareness, and proper medical support. Avoiding misuse of drugs is essential for maintaining good health.
8. Explain the structure and function of an ecosystem.
An ecosystem is a community of living organisms interacting with their physical environment. It consists of producers, consumers, and decomposers.
Producers, such as green plants, prepare food by photosynthesis. Consumers depend on plants or other animals for food. Decomposers break down dead organisms and recycle nutrients back into the environment.
Energy flows through ecosystems in the form of food chains and food webs. A balanced ecosystem is essential for environmental stability and survival of living organisms.
9. Describe transport systems in plants.
Plants require transport systems to move water, minerals, and food. This is carried out by specialized tissues called xylem and phloem.
Xylem transports water and minerals from roots to other parts of the plant. Phloem transports prepared food from leaves to growing and storage regions.
Transport systems are essential for plant growth, photosynthesis, and survival.
Conclusion
Practicing long questions helps students develop clear understanding and strong writing skills. These Class 9 and Class 10 Biology long questions are designed to support detailed revision and effective exam preparation.
Students should combine written practice with MCQs for balanced learning and better performance.