The Science of Biology · Biology Grade 9 · Unit 1 · Athens Academy Islamabad

Athens Academy Islamabad · Study Notes

The Science of Biology

BoardFBISE

Grade · Subject · UnitGrade 9 · Biology · Unit 1

Exam SessionExam 2027

Weight★★★ Definite — appears every year

Section 1

Introduction to Biology

Definition — examinable

Biology is the study of living organisms. It helps us explain how living things relate to one another and to their surroundings.

Memory hook

bios = life. logos = thought, reasoning and study. Biology = life + study.

1.1 Quranic Instructions

Learn the heading of each verse. That is what the marks are for.

Heading	Reference	Key point
Origin of Life in Water	Sura Ambia 21, Ayat 30	Living things are 60 to 90 percent water, so all life has a common origin.
Creation of Man	Sura Rehman, Ayat 14	Two steps: creation from water, then clay mixed with water.
Development	Sura Al-Mominoon, Ayat 14	The sequence of developmental stages of the embryo.

Common trap

The third heading is Development, not “Reproduction”.

1.2 Muslim Scientists

Jabir Bin Hayyan, Abdul Malik Asmai and Bu Ali Sina contributed to present-day knowledge of plants and animals. Your chapter gives the three names only — no book titles are required.

Section 2

Major Fields of Biology

Figure 1. The three divisions of biology.

Common trap — this is a textbook MCQ

“Microbiology is the study of:” offers fungi as a choice. The answer is microorganisms.

2.1 The Fifteen Sub-fields

All fifteen are examinable. Learn each name with its one-line definition.

Sub-field	Study of…
Morphology	Size, shape and structure of organisms
Anatomy	Internal structure. Also called internal morphology
Physiology	Functions of the various organs
Histology	Tissues, under a microscope
Cytology	Structure and functions of the cell. Also called cell biology
Genetics	Genes and heredity
Molecular biology	Biology at the molecular level
Embryology	Development of an organism from a fertilized egg
Paleontology	History of life on Earth, based on fossils
Taxonomy	Classification and naming of organisms, e.g. Homo sapiens
Ecology	Interrelationship of organisms and their environment. Also called environmental biology
Marine biology	Organisms that live in the sea
Pathology	Study and diagnosis of diseases
Immunology	Immunity — the body's ability to protect itself from foreign substances and microbes
Pharmacology	Drugs

Memory hook — the four students mix up

Shape, inside, function, tissue. Morphology, Anatomy, Physiology, Histology.

Wrong	Right
Microbiology = fungi	Microbiology = microorganisms
Environmental biology is separate	Environmental biology = ecology
Paleontology = development	Paleontology = fossils
Histology = cells	Histology = tissues; cytology = cells

Section 3

Relationship with Other Sciences

Biology is not an isolated science. Animals move on the principles of physics, and the behaviour of atoms and molecules explains the behaviour of a living cell. Long question: name the field, define it in one line.

Joined field	Definition
Biophysics	Study of biological phenomena according to the principles and laws of physics, e.g. movement of muscles and bones
Biochemistry	Study of chemical constituents in an organism and the chemical reactions taking place in it, e.g. digestion, respiration, photosynthesis
Biostatistics	Collecting biological data and analysing it by statistical rules. Also called biometry
Computational biology	Data analysis, mathematical modeling and simulations to understand biological systems, e.g. locating DNA fragments on chromosomes
Biogeography	Distribution of plants and animals in different geographical regions
Biotechnology	Techniques used to manipulate living organisms for the benefit of mankind
Bio-economics	Biology from an economic point of view, e.g. export value of wheat, fish and rice

Memory hook

Each name is bio- plus the partner subject. Physics → biophysics. Geography → biogeography. Name the partner and you can build the word.

Section 4

Careers Requiring Biology

Long question. Name the field, define it in one line, give one career from it.

Field	What it is · careers
Medicine and surgery	Diagnosis and treatment of disease; surgery removes or replaces defective organs · MBBS, then specialisation
Fisheries	Contributes significantly to Pakistan's economy · fish farming, fishery management
Farming and agriculture	Farming is growing crops and animals; agriculture is the science of improving farming · food science, agricultural engineering
Animal husbandry	Care and breeding of domestic animals · veterinary science, animal breeding
Biotechnology	Using living organisms to make useful products · bacteriology, virology, molecular genetics
Horticulture	The art of gardening · plant breeding
Forestry	Planting, managing and caring for forests · forest ecology

Section 5

Science as a Collaborative Field

Definition — examinable

When researchers from different fields work together to create new scientific knowledge, it is called interdisciplinary research collaboration.

Long question. Give the definition, then two or three examples:

Example	Combines
Bioinformatics	Biology + information technology; helps us understand complex biological data
Cognitive science	Neurology, psychology, linguistics and statistics
Public health	Medicine, sociology and psychology
International Space Station	Space agencies of Europe, the USA, Russia and Japan

Section 6

The Biological Method

Definition — examinable

The biological method is the series of steps used by biologists to solve a biological problem.

Figure 2. The order is examinable — learn it as a sequence.

Step	What happens
1. Recognition	A biological problem is a question related to living organisms
2. Observations	Made by the five senses. Two types — qualitative and quantitative
3. Hypothesis	A statement that may prove to be the answer to the problem
4. Deductions	Logical consequences of the hypothesis, using “if…then” logic
5. Experimentation	The most important step. Tests whether the hypothesis is true
6. Summarization	Quantitative data is gathered and arranged to draw results

6.1 The Two Types of Observation

Type	Based on	Example
Qualitative	A quality or characteristic	Colour of a cat, song of a bird
Quantitative	A measurable value	Height of a giraffe, body temperature

Quantitative observations are more accurate, because they are measurable and can be expressed in numbers.

Memory hook

Qualitative = quality (a word). Quantitative = quantity (a number).

6.2 The Four Characteristics of a Good Hypothesis

Learn all four — they are asked together

(a) a general statement · (b) a tentative idea · (c) agrees with the available observations · (d) testable and potentially falsifiable

Common trap

A hypothesis is a statement, never a question. “Plasmodium is the cause of malaria” earns the mark.

Control group — an MCQ

An experiment tests an experimental group alongside an untreated control group, in parallel, for comparison.

Section 7

Hypothesis, Theory and Law

Term	Definition
Hypothesis	A tentative answer to a question, based on past experience and available data. Makes a testable prediction using “if…then” logic
Theory	Much broader in scope than a hypothesis and supported by more evidence. Can still be modified or rejected if new results do not fit
Biological law	A theory that has been verified and appears to have wide application, e.g. Mendel's law of inheritance

Figure 3. Block height stands for weight of evidence.

Memory hook

H → T → L. Growing evidence, growing certainty.

Common trap — a whole MCQ rests on this

A theory is not a guess. A theory rests on a wide range of evidence; a hypothesis is the one based on limited data. Never write that a theory is an educated guess.

Data is the collection of facts or information. It is organised using tables and graphs, then analysed by means of ratio and proportion — a ratio compares one number with another, such as $3:1$.

Section 8

Malaria — The Biological Method in Action

Symptoms

Chill and cold; temperature rises above the normal 98.6°F; headache and nausea; then sweating and relief. The cycle repeats every 24, 48 or 72 hours depending on the species of Plasmodium.

8.1 Stage One — The Cause

Step	What was done
Problem	Malaria was fatal since ancient times, but its cause was unknown
Observations	(a) malaria relates to marshy areas; (b) quinine is an effective drug; (c) drinking marsh water does not cause malaria; (d) Plasmodium is seen in patients' blood
Hypothesis	By the French physician Laveran, 1882: “Plasmodium is the cause of malaria”
Deduction	If so, then all persons ill with malaria should have Plasmodium in their blood
Experiment	Blood of 100 patients examined, plus 100 healthy persons as the control group
Results	Almost all patients had it. Only 7 of 100 healthy persons did — those 7 were in the incubation period and fell ill days later

Definition — examinable

The incubation period is the time between the entry of the parasite into the host and the appearance of the symptoms of disease.

8.2 Stage Two — The Spread

Step	What was done
Observations	A. F. A. King, 1883: people sleeping outdoors got malaria more often; those under fine nets less often; those near smoky fires usually did not
Hypothesis	King: “Mosquitoes transmit Plasmodium so are involved in the spread of malaria”
Deductions	I: Plasmodium should be present in the mosquito. II: a mosquito can get it by biting a patient
Experiments	Ronald Ross, 1897: a female Anopheles bit a patient — Plasmodium was later found multiplying in its stomach. With sparrows, Culex passed malaria from sick to healthy birds. An Italian biologist repeated it on humans
Results	The mosquito transmits Plasmodium and spreads malaria

Definition — examinable

A vector is any organism which carries a parasite and transfers it from one organism to another.

Figure 4. Malaria in man is carried by Anopheles; in birds by Culex.

Memory hook — this exact table is an MCQ

Humans → Anopheles. Birds → Culex. Dengue → Aedes aegypti. Learn the three as a set, because the MCQ scrambles them.

The single most common error in this unit

Malaria is not caused by the mosquito. It is caused by Plasmodium. Plasmodium = cause. Mosquito = vector.

Dengue fever is caused by a Dengue virus and carried by Aedes aegypti, which has zebra-like white and black stripes. There is no specific antiviral drug; a second attack can be more dangerous. Prevention is protection from bites and stopping mosquito breeding.

Practice

Worked Scenarios

Scenario 1 — Identifying the correct step

Given	A student wants to investigate factors affecting the activity of salivary amylase (the -ase ending marks an enzyme).
Required	The most appropriate first step.
Approach	Run through the six steps in order and find what must come first.
Steps	An experiment needs a deduction; a deduction needs a hypothesis; a hypothesis needs observations. All of these need a question to exist first.
Result	Every investigation starts by recognising a biological problem.
Answer	State the problem: “Which factors affect the activity of salivary amylase?”

Step 1 — Recognition of the biological problem.

Scenario 2 — Writing a hypothesis and a deduction

Given	Malaria is associated with marshes; sleepers under nets rarely get it; sleepers near smoky fires usually do not.
Required	One hypothesis and one deduction.
Approach	The hypothesis must be a general, tentative, testable statement fitting all observations. The deduction uses “if…then”.
Steps	All three observations point to something that flies, that a net blocks and that smoke drives away — an insect.
Result	The hypothesis is testable: dissect a mosquito and look.
Answer	Hypothesis: mosquitoes transmit Plasmodium and are involved in the spread of malaria. Deduction: if so, Plasmodium should be present in the mosquito.

Hypothesis: mosquitoes transmit Plasmodium. Deduction: it should be present in the mosquito.

Scenario 3 — Explaining an unexpected result

Given	Hepatitis B virus was found in the blood of 10 persons, but only 6 had the disease.
Required	Explain the other 4.
Approach	Compare with the malaria experiment, where 7 of 100 healthy persons carried Plasmodium.
Steps	A parasite does not cause symptoms immediately. There is a gap between entry and symptoms, during which a person tests positive but feels well.
Result	Those 4 are likely to develop the disease later.
Answer	They are in the incubation period.

Incubation period — carrying the virus, symptoms not yet shown.

Revision

Revision Checklist

Tick a line only when you can say it aloud without looking.

Define biology; give bios and logos.
Name the three divisions and what each studies.
Microbiology = microorganisms, not fungi.
Define ten of the fifteen sub-fields in one line each.
State the three Quranic headings, including Development.
Living things are 60 to 90 percent water.
Name the three Muslim scientists.
Name the seven joined fields, biophysics to bio-economics.
Name five careers and define each in one line.
Define interdisciplinary research collaboration, with one example.
List the six steps of the biological method in order.
Distinguish qualitative and quantitative; say which is more accurate.
Give the four characteristics of a good hypothesis.
Distinguish hypothesis, theory and law.
Define control group.
Retell malaria — cause and spread — naming Laveran, King and Ross.
Match vector to disease: Anopheles, Culex, Aedes aegypti.
Define vector and incubation period.

Final word from Athens Academy Islamabad

Three things carry most of the marks in this unit: the sub-field definitions, the six steps in order, and malaria as the worked example of those six steps.

If you remember one line today, make it this: Plasmodium is the cause, the mosquito is the vector. Take one section at a time — you can absolutely do this.

🌱 Chapter 1 · The Science of Biology