🔬 BIOLOGY FORM 1 SUMMARY NOTES

1. Introduction to Biology

Biology: The study of living things.

Branches of Biology:

Botany – Study of plants.

Zoology – Study of animals.

Ecology – Study of organisms and their environment.

Importance of Biology:

Medicine, agriculture, conservation, research, etc.

Characteristics of living things:

Nutrition, respiration, excretion, growth, reproduction, movement, sensitivity.

 2. Classification of Living Things

Taxonomy: The science of classification.

Major groups of living things:

Plants, animals, fungi, protoctists, monera (bacteria).

Binomial nomenclature:

Two-name system (Genus + species) e.g., Homo sapiens.

Kingdoms:

Kingdom Monera, Protista, Fungi, Plantae, Animalia.

3. The Cell
Cell: Basic unit of life.

Types of cells:

Plant cells (have cell wall, chloroplasts, large vacuole)

Animal cells (no cell wall, no chloroplasts, small/absent vacuole)

Cell structures:

Nucleus, cell membrane, cytoplasm, mitochondria, vacuole, etc.

Cell theory:

All living things are made of cells.

Cells are the basic units of life.

All cells come from pre-existing cells.

 4. Cell Physiology

Diffusion: Movement of particles from high to low concentration.

Osmosis: Movement of water from high to low water concentration across a

semi-permeable membrane.

Importance: Absorption in roots, kidney function, etc.

Turgor pressure: Helps plant support.

5. Nutrition in Plants and Animals

a. Nutrition in Plants

Photosynthesis:

Process by which green plants make food using CO₂, water, and sunlight.

Occurs in chloroplasts.

Equation:

CO₂ + H₂O → (light + chlorophyll) → Glucose + O₂

Factors affecting photosynthesis:

Light, carbon dioxide, temperature, chlorophyll.

b. Nutrition in Animals

Types of feeding:

Herbivores, carnivores, omnivores.

Human digestive system:

Ingestion → digestion → absorption → assimilation → egestion.

Organs: Mouth, stomach, intestines, liver, pancreas, etc.

6. Transport in Plants and Animals

Transport in plants:
Xylem: Transports water and minerals.

Phloem: Transports food (sugars).

Transpiration: Loss of water through stomata.

Transport in animals:

Circulatory system: Heart, blood, and blood vessels.

Functions of blood: Transport, defense, regulation.

7. Respiration

Respiration: Release of energy from food.

Types:

Aerobic (uses oxygen)

Anaerobic (without oxygen)

Equation for aerobic respiration:

Glucose + O₂ → CO₂ + H₂O + Energy

8. Excretion and Homeostasis

Excretion: Removal of waste products.

Excretory organs in humans: Kidneys, skin, lungs, liver.

Homeostasis: Maintenance of a constant internal environment (e.g.,

temperature, pH, water balance).

9. Growth and Development

Growth: Increase in size and mass.

Development: Increase in complexity.

Occurs in stages and is influenced by hormones, genes, and nutrition.

 10. Reproduction

Types:

Asexual (one parent, no gametes).

Sexual (two parents, involves gametes).

Human reproductive system:

Male: Testes, penis.

Female: Ovaries, uterus, vagina.

11. Ecology

Ecology: Study of relationships between organisms and their environment.

Key terms:

Habitat, niche, population, community, ecosystem.

Adaptations: Features that help

Biology Form 2 Summary Notes

1. Transport in Plants and Animals

Transport in Plants

Plants have two main transport tissues: xylem (water & mineral salts) and
phloem (sugars).

Xylem transports water from roots to leaves via transpiration pull.

Phloem carries food (sucrose, amino acids) from leaves to other parts –
process is called translocation.

Transpiration: Loss of water vapor through stomata; helps in cooling and

movement of water.
Factors affecting transpiration: temperature, humidity, wind, light.

Transport in Animals

Human circulatory system is double and closed.

Blood vessels: arteries (carry blood away from heart), veins (to the heart),
capillaries (exchange of materials).

Heart chambers: right atrium, right ventricle, left atrium, left ventricle.

Blood components: RBCs (transport oxygen), WBCs (immunity), platelets

(clotting), plasma (transport).

Lymphatic system: returns excess tissue fluid to bloodstream, helps in

defense.

2. Gaseous Exchange

In Plants

Occurs through stomata (leaves) and lenticels (stems).

During the day: take in CO₂, release O₂ (photosynthesis).

At night: take in O₂, release CO₂ (respiration).

In Animals

Gaseous exchange organs: gills (fish), lungs (mammals), skin (frogs).

Human respiratory system: nose → trachea → bronchi → bronchioles →

alveoli.

Alveoli: site of gas exchange (O₂ in, CO₂ out), surrounded by capillaries.

Inhalation: diaphragm contracts, rib cage expands.

Exhalation: diaphragm relaxes, rib cage drops.

3. Respiration

Respiration: breakdown of glucose to release energy.

Types:

Aerobic (with oxygen): Glucose + O₂ → CO₂ + H₂O + Energy (ATP).

Anaerobic (without oxygen): Less energy, produces lactic acid (in animals) or
ethanol + CO₂ (in yeast).

Occurs in mitochondria.

4. Excretion and Homeostasis

Excretion

Removal of metabolic wastes (CO₂, urea, excess salts).

Excretory organs:

Lungs – CO₂

Skin – salts & water (sweat)

Kidneys – urea, excess water & salts (urine)

Kidney structure: cortex, medulla, pelvis; functional unit is nephron.

Homeostasis

Maintaining stable internal conditions.

Controlled through feedback mechanisms.

Examples:

Temperature control (sweating, shivering).

Blood sugar regulation (insulin & glucagon).

5. Growth and Development

Growth: increase in size/mass.

Development: progression to maturity (functional changes).

Occurs via cell division (mitosis) and cell enlargement.

Human growth stages: infancy, childhood, adolescence, adulthood, old age.

Germination: seed → seedling; conditions needed: water, oxygen, warmth.

6. Reproduction in Plants and Animals

Asexual Reproduction

One parent; offspring identical (clones).

Examples: budding (yeast), binary fission (bacteria), vegetative propagation

(plants).

Sexual Reproduction

Involves fusion of gametes (male + female).

In plants:

Pollination: transfer of pollen from anther to stigma.

Fertilization: fusion of gametes in ovary → seed.

Flower parts: stamen (male), carpel (female).

In animals:

Male: testes (produce sperm)

Female: ovaries (produce eggs)

Fertilization → zygote → embryo → fetus.

🌿 BIOLOGY FORM 3 SUMMARY NOTES

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1. Classification II (Kingdoms & Binomial Nomenclature)

Five Kingdoms:

Monera: Bacteria (prokaryotic, unicellular).

Protista: Amoeba, Euglena (mostly unicellular, eukaryotic).

Fungi: Moulds, mushrooms (heterotrophic, saprophytic).

Plantae: Mosses, ferns, flowering plants (autotrophic).

Animalia: Vertebrates & invertebrates (heterotrophic, complex).

Binomial Nomenclature:

Developed by Carolus Linnaeus.

Format: Genus species (italicized or underlined).

E.g., Homo sapiens.

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2. Ecology

Ecosystem: Interaction between living (biotic) and non-living (abiotic)

components.

Components:

Biotic: Producers (plants), consumers (herbivores, carnivores), decomposers

(fungi, bacteria).

Abiotic: Soil, water, temperature, light.

Food Chain & Food Web:

Shows energy flow.

Trophic levels: Producer → Primary → Secondary → Tertiary consumers.

Pyramid of numbers/biomass/energy.

Adaptations:

Plants and animals adapt to survive in different environments (deserts,

aquatic, forests).

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3. Growth and Development in Plants and Animals

Growth: Irreversible increase in size and mass.

Development: Changes in form and function.

Germination types:
Epigeal: Cotyledons above ground (e.g., bean).

Hypogeal: Cotyledons remain below ground (e.g., maize).

Growth curves: S-shaped (sigmoid) curve.

Lag phase → Log phase → Plateau.

Factors affecting growth: Genes, hormones (auxins, gibberellins), water,

light, nutrients.

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4. Reproduction in Plants and Animals

Asexual reproduction:

No gametes involved.

E.g., Binary fission, budding, spore formation.

Sexual reproduction:

Male and female gametes fuse.

Involves fertilization and genetic variation.

Human Reproductive System:

Male: Testes, sperm ducts, penis.

Female: Ovaries, fallopian tubes, uterus, vagina.

Menstrual cycle: ~28 days, regulated by hormones.

Fertilization: Fusion of sperm and ovum → zygote → embryo.

Contraception: Natural, mechanical, hormonal, surgical methods.

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5. Reproductive Health

STIs/STDs: HIV/AIDS, syphilis, gonorrhea, herpes.

Transmission: unprotected sex, blood transfusion, sharing needles.

Prevention: Abstinence, condoms, education, screening.

Teenage pregnancy: Social, health, and educational impacts.

Family planning: Helps regulate population growth.

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6. Genetics I

Genetics: Study of heredity and variation.

Mendelian inheritance:

Genes: Units of heredity.

Alleles: Forms of a gene.

Genotype vs Phenotype.

Dominant vs Recessive traits.

Monohybrid Crosses: One trait.

Punnett squares to predict outcomes.

Variation:

Continuous (height, weight).

Discontinuous (blood group, tongue rolling).

7. Transport in Plants and Animals

Transport in plants:

Xylem: Water & minerals (root to leaves).

Phloem: Food (leaves to other parts).

Processes: Diffusion, osmosis, active transport, transpiration.

Transport in animals:
Human circulatory system: Heart, blood, vessels.

Blood vessels:

Arteries: Away from heart.

Veins: To the heart.

Capillaries: Exchange of materials.

Blood components:

Plasma, red blood cells, white cells, platelets.

Heart structure: 4 chambers (atria & ventricles).

Double circulation: Pulmonary & systemic.

🔬 Biology Form 4 Summary Notes

 1. Reproduction in Plants and Animals

a) Asexual Reproduction

Involves one parent.

Offspring are genetically identical (clones).

Examples: Binary fission, budding, spore formation, vegetative propagation

(e.g., tubers, runners).

b) Sexual Reproduction

Involves fusion of male and female gametes.

Leads to genetic variation.

In plants: Pollination (self and cross), fertilization, seed and fruit formation.

In animals: Internal and external fertilization, development of embryo.

c) Human Reproductive System

Male: Testes, sperm duct, urethra, penis.

Female: Ovaries, oviducts, uterus, cervix, vagina.

Menstrual cycle: Hormonal control (FSH, LH, estrogen, progesterone).

Fertilization and implantation.

2. Growth and Development

Growth: Irreversible increase in size and mass.

Development: Increase in complexity and functionality.

Measured by increase in size, number of cells, or dry weight.

Germination types: Epigeal and hypogeal.

Factors affecting growth: Temperature, water, oxygen, nutrients.

3. Genetics

a) Basic Genetics
Gene: Unit of inheritance.

Alleles: Different forms of a gene.

Dominant vs. Recessive traits.

Homozygous (same alleles), Heterozygous (different alleles).

Genotype vs. Phenotype.

b) Mendelian Inheritance

Mendel’s laws: Segregation and Independent Assortment.

Use of Punnett squares to predict genotypic and phenotypic ratios.

c) Variation and Mutation

Variation: Continuous (e.g., height) and Discontinuous (e.g., blood groups).

Mutation: Sudden change in genes or chromosomes; can be beneficial or

harmful.
 4. Evolution

The gradual change in organisms over generations.

Natural selection: Survival of the fittest.

Evidence of evolution: Fossils, comparative anatomy, embryology.

5. Respiration

Aerobic: With oxygen, more energy produced.

Anaerobic: Without oxygen, less energy, produces lactic acid (animals) or

ethanol and CO₂ (yeast).

Word & chemical equations for respiration.

6. Ecology (continued)
Energy flow: Food chains and webs, trophic levels, energy pyramids.

Nutrient cycles: Carbon and nitrogen cycles.

Human impact: Pollution, conservation, deforestation, endangered species.

7. Excretion and Homeostasis

a) Excretion

Removal of metabolic waste (e.g., urea, CO₂).

Human excretory organs: Kidneys, lungs, skin.

Structure and function of the nephron.

b) Homeostasis

Maintenance of a constant internal environment.

Regulation of blood sugar (insulin and glucagon).

Thermoregulation: Vasodilation and vasoconstriction.

 8. Support and Movement in Plants and Animals

a) Support in Plants

Turgor pressure, lignified tissues (xylem), collenchyma, sclerenchyma.

b) Support and Movement in Animals

Skeleton types: Hydrostatic, exoskeleton, endoskeleton.

Human skeleton: Axial and appendicular.

Joints: Fixed, hinge, ball-and-socket.

Muscles: Antagonistic pairs (e.g., biceps and triceps).

9. Coordination and Response

a) Nervous System
Central and peripheral nervous systems.

Neurons: Sensory, motor, relay.

Reflex arc and mechanism of response.

b) Sense Organs

Eye: Structure (cornea, lens, retina) and function.

Ear: Hearing and balance.

c) Endocrine System

Glands: Pituitary, thyroid, pancreas, adrenal.

Hormones: Chemical messengers (e.g., insulin, adrenaline).