Biology 9th is a foundational subject under the Lahore Board and Punjab Board syllabus. The science of biology explores the study of life, organisms, and their interactions, helping students build essential knowledge for higher studies in medicine, agriculture, and environmental sciences.
1. Which branch of Biology focuses on the study of the structure and function of cells?
- Options:
a) Cytology
b) Microbiology
c) Histology
d) Ecology - Answer: a) Cytology
- Tip/Trick: The prefix “cyto-” means “cell,” so Cytology is the study of cells.
2. The study of the processes of heredity and variation in living organisms is known as:
- Options:
a) Ecology
b) Genetics
c) Anatomy
d) Proteomics - Answer: b) Genetics
- Tip/Trick: Genetics deals with genes and inheritance, which govern heredity and variation.
3. Insulin made through bacteria is an example of the technique of:
- Options:
a) Parasitology
b) Biotechnology
c) Biochemistry
d) Histology - Answer: b) Biotechnology
- Tip/Trick: Biotechnology involves using organisms or biological processes to create useful products like insulin.
4. Heart pumps, the brain memorizes, kidneys excrete. The statement comes from:
- Options:
a) Physiology
b) Anatomy
c) Morphology
d) Cardiology - Answer: a) Physiology
- Tip/Trick: Physiology focuses on the functions and processes of living organisms and their parts.
5. Which branch of Biology involves the study of the classification of organisms?
- Options:
a) Taxonomy
b) Physiology
c) Palaeontology
d) Biogeography - Answer: a) Taxonomy
- Tip/Trick: Taxonomy is about naming, classifying, and organizing organisms into groups.
6. Which step comes between making a hypothesis and doing experiments?
- Options:
a) Making deductions
b) Making observations
c) Summarizing results
d) Analyzing data - Answer: b) Making observations
- Tip/Trick: Observations help refine hypotheses and guide experimental design.
7. Which of the following is NOT a characteristic of the scientific method?
- Options:
a) It relies on evidence
b) It involves formulating hypotheses
c) Hypotheses will always be correct
d) It requires rigorous testing - Answer: c) Hypotheses will always be correct
- Explanation: Hypotheses are tentative explanations and can be disproven.
- Tip/Trick: Remember that in science, hypotheses are tested and may be rejected or refined.
8. Choose the correct sequence of steps of the scientific method.
- Options:
a) Observations → hypothesis → deduction → experiments
b) Observations → hypothesis → law → theory
c) Hypothesis → observations → deduction → experiments
d) Law → theory → deduction → observations - Answer: a) Observations → hypothesis → deduction → experiments
- Explanation: The scientific method begins with observations, followed by forming a hypothesis, making deductions, and performing experiments.
- Tip/Trick: Think of it as “observe first, then hypothesize, test, and conclude.”
9. People who slept near smoky fire had less chance to suffer from malaria. Why?
- Options:
a) Smoke kills Plasmodium in their blood
b) Fire increases temperature and Plasmodium are killed in air
c) Mosquitoes cannot tolerate smoke and are repelled
d) Smoke kills Plasmodium present in mosquitoes - Answer: c) Mosquitoes cannot tolerate smoke and are repelled
- Explanation: Smoke repels mosquitoes, reducing their bites and preventing the spread of malaria.
- Tip/Trick: Remember that mosquitoes are the carriers of malaria, and repelling them is effective.
10. Experiments are very important in the scientific method because a researcher:
- Options:
a) Always gets correct results
b) Disproves many hypotheses and gets some hypotheses proved
c) Is sure that he will prove the hypotheses
d) Gets a chance to work in the laboratory - Answer: b) Disproves many hypotheses and gets some hypotheses proved
- Explanation: Experiments validate or refute hypotheses, advancing scientific understanding.
- Tip/Trick: Science progresses by eliminating incorrect hypotheses and validating correct ones.
Short Questions
1. Define the following branches of Biology:
- Genetics: The study of heredity and the variation of inherited traits.
- Anatomy: The study of the structure of organisms and their parts.
- Palaeontology: The study of fossils to understand past life and evolution.
- Marine Biology: The study of organisms in the ocean and other saltwater environments.
- Pathology: The study of diseases, their causes, and effects.
2. Which branch of Biology involves the study of the development and growth of organisms from fertilization to adulthood?
- Answer: Embryology.
- Explanation: Embryology focuses on the development of organisms from a single cell to maturity.
3. How is the profession of medicine and surgery different from animal husbandry?
- Answer: Medicine and surgery deal with diagnosing and treating human diseases, while animal husbandry involves breeding, feeding, and caring for animals for agricultural purposes.
4. Differentiate between Morphology and Physiology.
- Answer:
- Morphology: The study of the structure, shape, and form of organisms.
- Physiology: The study of the functions and processes of living organisms.
5. What is Computational Biology?
- Answer: Computational Biology is the application of data analysis, mathematical models, and algorithms to study biological systems.
6. What is the role of observation and experimentation in the scientific method?
- Answer: Observation helps identify patterns and formulate hypotheses, while experimentation tests these hypotheses to validate or refute them.
Detailed Answers for Section C
1. Link the study of Biology with that of Physics, Chemistry, Statistics, Geography, Economics, and Computer Science.
- Biology is interconnected with many disciplines:
- Physics: Explains biological phenomena like fluid dynamics in blood flow and biomechanics in movement.
- Chemistry: Essential for understanding biochemical reactions like photosynthesis, respiration, and digestion.
- Statistics: Helps in analyzing experimental data, such as population genetics or epidemiological studies.
- Geography: Influences ecosystems, biodiversity, and environmental studies.
- Economics: Impacts resource management, agricultural biology, and biotechnology industries.
- Computer Science: Supports bioinformatics, genetic sequencing, and computational biology for data analysis and modeling.
2. Explain how the study of Biology can lead to different professional studies.
- Biology serves as a foundation for numerous professions:
- Medicine and Surgery: Diagnosis and treatment of diseases.
- Agriculture and Horticulture: Crop production and pest management.
- Environmental Science: Ecosystem conservation and pollution control.
- Biotechnology: Development of medicines, vaccines, and genetically modified crops.
- Pharmaceuticals: Drug design and clinical research.
- Research: Advancing knowledge in genetics, microbiology, and molecular biology.
3. Science is a collaborative field in which scientists work together to share knowledge. Prove this statement by giving examples.
- Collaboration is vital for scientific progress:
- Human Genome Project: Involved scientists from various countries to map all human genes.
- COVID-19 Vaccine Development: Teams across the globe shared data to develop effective vaccines quickly.
- Discovery of DNA Structure: James Watson, Francis Crick, Rosalind Franklin, and Maurice Wilkins worked together to elucidate DNA’s double helix.
- Climate Change Research: Requires collaboration between biologists, geographers, and meteorologists.
4. How is a hypothesis converted to theory, law, and principle?
- Hypothesis: A testable statement based on observations.
- Example: “Plants grow faster with more sunlight.”
- Theory: When a hypothesis is repeatedly tested and supported by evidence.
- Example: The Theory of Evolution explains biodiversity through natural selection.
- Law: A universal statement that describes a consistent natural phenomenon.
- Example: Mendel’s Laws of Inheritance explain genetic traits.
- Principle: A fundamental truth that serves as a basis for other scientific concepts.
- Example: The Principle of Homeostasis explains the stability of internal environments.
5. What are the basic steps a scientist adopts in order to solve scientific problems?
- Steps in the Scientific Method:
- Observation: Identify a phenomenon or problem.
- Hypothesis: Propose a possible explanation.
- Experimentation: Design and conduct tests to validate the hypothesis.
- Data Analysis: Interpret experimental results.
- Conclusion: Accept, reject, or refine the hypothesis.
- Publication: Share findings for peer review.
6. Describe the work of different scientists in discovering the cause of malaria.
- Charles Laveran: First observed the malaria parasite in a patient’s blood in 1880.
- Patrick Manson: Demonstrated the transmission of parasites through mosquitoes.
- Ronald Ross: Proved that the Anopheles mosquito is the vector for malaria by showing parasites in the mosquito’s stomach.
- Giovanni Battista Grassi: Confirmed Ross’s findings and identified the lifecycle of the parasite.
7. Write a descriptive note on the experiments performed by Ross.
- Ronald Ross’s experiments:
- In 1897, Ross dissected mosquitoes fed on malaria-infected patients and found Plasmodium parasites in their stomachs.
- He demonstrated the lifecycle of Plasmodium in mosquitoes, showing that mosquitoes were the vector for malaria.
- His experiments took place in India, where he meticulously studied mosquito behavior and malaria transmission.
- His work earned him the Nobel Prize in 1902, revolutionizing the understanding and prevention of malaria.
