13 chapters · Topics & Key Concepts
Nature of science, scientific method, observation, hypothesis, experiment, theory, units and measurement, scientific instruments, importance of curiosity and inquiry, history of scientific discoveries
Science is a systematic way of understanding the natural world through observation, questioning, experimenting and reasoning. The scientific method begins with curiosity, leads to a hypothesis, is tested by experiment and produces theories and laws. Measurements are central to science; standard SI units allow comparison worldwide. Science welcomes questioning and revision in light of new evidence.
Discovery of cell, cell theory, prokaryotic and eukaryotic cells, plant cell vs animal cell, cell organelles (nucleus, mitochondria, chloroplast, ER, Golgi, ribosomes, lysosomes, vacuoles), plasma membrane, cell wall, diffusion, osmosis, hypotonic/hypertonic/isotonic solutions
The cell is the structural and functional unit of life. The cell theory (Schleiden, Schwann, Virchow) states all living organisms are made of cells and all cells arise from pre-existing cells. Prokaryotic cells lack a true nucleus while eukaryotic cells have one. Mitochondria are the powerhouse, ribosomes synthesise proteins, and chloroplasts perform photosynthesis. The plasma membrane regulates entry and exit of substances by diffusion and osmosis.
Plant tissues (meristematic and permanent), apical/lateral/intercalary meristems, simple permanent tissues (parenchyma, collenchyma, sclerenchyma), complex permanent tissues (xylem, phloem), animal tissues (epithelial, connective, muscular, nervous), types of each
Tissues are groups of similar cells performing a common function. In plants, meristematic tissue divides to produce new cells and permanent tissue performs specialised functions. Xylem and phloem are vascular tissues for transport. In animals, four basic tissue types exist: epithelial (covering), connective (support), muscular (movement) and nervous (control). Each tissue has a structure suited to its function.
Rest and motion, scalar and vector quantities, distance and displacement, uniform and non-uniform motion, speed, velocity, acceleration, equations of motion, graphical representation, uniform circular motion
Motion is change in position with respect to time. Distance is a scalar (total path); displacement is a vector (shortest path). Slope of distance-time graph = speed; slope of velocity-time graph = acceleration; area under v-t graph = displacement. Circular motion at constant speed is accelerated motion because direction keeps changing.
Pure substances and mixtures, homogeneous and heterogeneous mixtures, solutions, suspensions, colloids, Tyndall effect, concentration of solution, separation techniques (filtration, evaporation, distillation, chromatography, centrifugation, crystallisation), physical and chemical changes
Matter exists as pure substances (elements and compounds) and mixtures. Solutions are homogeneous (e.g., salt water); suspensions and colloids are heterogeneous. The Tyndall effect distinguishes colloids by scattering of light. Mixtures can be separated by physical methods exploiting differences in properties. Physical changes are reversible; chemical changes form new substances.
Force, balanced and unbalanced forces, Newton's laws of motion, inertia, momentum, law of conservation of momentum, friction, gravitational force, free fall, mass and weight, thrust and pressure
A force is a push or pull. Newton's first law (inertia) states a body continues in its state unless acted on by an unbalanced force. The second law gives F = ma. The third law states every action has an equal and opposite reaction. Momentum is conserved in an isolated system. Pressure depends on force and area.
Work, positive/negative/zero work, energy, kinetic energy, potential energy, mechanical energy, law of conservation of energy, power, commercial unit of energy, simple machines (lever, pulley, inclined plane), mechanical advantage
Work is done when a force produces displacement in its direction. Energy is the capacity to do work. Kinetic energy is the energy of motion; potential energy is stored energy due to position. Energy cannot be created or destroyed, only transformed. Power is the rate of doing work. Simple machines reduce effort or change the direction of force.
Discovery of electron (Thomson), proton (Goldstein), nucleus (Rutherford), neutron (Chadwick), atomic models (Thomson, Rutherford, Bohr), atomic number, mass number, isotopes, isobars, valency
An atom has protons (+ve) and neutrons in the nucleus, with electrons (-ve) revolving around it. Thomson proposed the plum pudding model; Rutherford's gold foil experiment proved a small, dense, positively charged nucleus. Bohr proposed fixed circular orbits. Atomic number distinguishes elements; mass number gives total nucleons. Isotopes and isobars highlight similarities and differences in atomic structure.
Laws of chemical combination, Dalton's atomic theory, atom, molecule, atomicity, ions, molecular mass, formula unit mass, mole concept, Avogadro number, chemical formulae
Matter is made of tiny indivisible particles called atoms, as proposed by Dalton. Atoms of an element are identical; atoms combine in fixed simple whole-number ratios. The mole is the SI unit for amount of substance; one mole contains Avogadro's number of particles. Mole concept connects mass, number of particles and volume of gases.
Production and propagation of sound, longitudinal wave, characteristics (wavelength, frequency, amplitude, time period, speed), pitch, loudness, quality, speed of sound in different media, reflection, echo, reverberation, range of hearing, ultrasound, SONAR
Sound is produced by vibrating objects and travels as a longitudinal wave through a material medium. Sound cannot travel in vacuum. Frequency determines pitch, amplitude determines loudness, and waveform determines quality. Sound travels fastest in solids. Reflection of sound gives echo and reverberation. Ultrasound is used in medical imaging, cleaning and SONAR.
Reproduction as a life process, asexual reproduction (binary fission, budding, fragmentation, spore formation, vegetative propagation), sexual reproduction in plants (parts of flower, pollination, fertilisation), sexual reproduction in humans, puberty, reproductive health
Reproduction is the biological process by which organisms produce offspring, ensuring continuity of life. Asexual reproduction involves a single parent and produces genetically identical offspring; sexual reproduction involves two parents and produces variation. In flowering plants, pollination is followed by fertilisation. In humans, fertilisation in the fallopian tube forms the zygote, which develops into the embryo.
Biodiversity, need for classification, basis of classification, hierarchy (kingdom, phylum, class, order, family, genus, species), five-kingdom classification (Monera, Protista, Fungi, Plantae, Animalia), binomial nomenclature
Biodiversity is the variety of life forms on Earth. Classification arranges organisms into groups based on similarities and differences, showing evolutionary relationships. Whittaker's five-kingdom classification groups organisms based on cell type, body organisation and mode of nutrition. Linnaeus introduced binomial nomenclature, giving each species a unique two-word scientific name.
Earth as a system, spheres of Earth (lithosphere, hydrosphere, atmosphere, biosphere), biogeochemical cycles (water, carbon, nitrogen, oxygen), greenhouse effect, climate change, natural resources, ecosystem balance, environmental conservation
Earth functions as an integrated system in which the lithosphere, hydrosphere, atmosphere and biosphere interact continuously, exchanging matter and energy. Biogeochemical cycles maintain the balance of essential elements. The greenhouse effect keeps Earth warm enough for life, but its enhancement by human activities is causing climate change. Sustainable use of natural resources and protection of biodiversity are essential.
