Biology — What's covered

Biology · Singapore O-Level (6093)

Every topic in the syllabus — and exactly where we teach it

The full national syllabus, mapped to our lessons. Each point below is a learning objective the exam can test, and a green tick means there is a lesson — podcast, notes, worksheet and diagrams — that covers it.

12syllabus themes33lessons130learning objectives100%covered end‑to‑end01

Cells & the Chemistry of Life

3 lessonsCell Structure and Organisation›

4 syllabus objectives covered

Identify and state the functions of cell structures (cell wall, cell membrane, cytoplasm, nucleus, cell vacuoles, chloroplasts) from diagrams, light micrographs, and under the light microscope.
Identify and state the functions of membrane systems and organelles (endoplasmic reticulum, Golgi body, mitochondria, ribosomes) from diagrams and electron micrographs.
Compare the structure of typical animal and plant cells.
Explain how the structures of specialised cells are adapted to their functions (e.g., muscle cell, root hair cell, red blood cell).

Movement of Substances›

3 syllabus objectives covered

Define diffusion and describe its role in nutrient uptake and gaseous exchange in plants and humans.
Define osmosis, investigate and describe the effects of osmosis on plant and animal tissues.
Define active transport and discuss its importance as an energy-consuming process by which substances are transported against a concentration gradient, as in ion uptake by root hairs and uptake of glucose by cells in the villi.

Biological Molecules›

4 syllabus objectives covered

List the chemical elements which make up carbohydrates, fats, and proteins.
State the main roles of carbohydrates, fats, and proteins in living organisms.
Describe and carry out tests for starch (iodine in potassium iodide solution), reducing sugars (Benedict's solution), protein (biuret solution), and fats (ethanol).
State that large molecules are synthesised from smaller basic units: cellulose, glycogen and starch from glucose; polypeptides and proteins from amino acids; lipids such as fats from glycerol and fatty acids.

Nutrition in Humans

1 lessonHuman Digestive System›

7 syllabus objectives covered

Describe the functions of the various parts of the digestive system in relation to ingestion, digestion, absorption, assimilation and egestion.
Describe peristalsis in terms of rhythmic wave-like contractions of muscles to mix and propel contents of the alimentary canal.
Describe the functions of enzymes (e.g. amylase, maltase, protease, lipase) in digestion, listing substrates and end-products.
Explain how the structure of a villus, including capillaries and lacteal, is suited for its function of absorption.
State the function of the hepatic portal vein as transport of blood rich in absorbed nutrients from the small intestine to the liver.
State the role of the liver in conversion of glucose to glycogen and vice versa, fat digestion, metabolism of amino acids and formation of urea, breakdown of alcohol and hormones.
Outline the effects of alcohol consumption on the brain and long-term effects of excessive consumption, and social implications.

Transport in Humans

3 lessonsParts and Functions of the Circulatory System›

3 syllabus objectives covered

Identify the main blood vessels to and from the heart, lungs, liver and kidney.
Relate the structures of arteries, veins and capillaries to their functions.
Describe the transfer of materials between capillaries and tissue fluid.

Blood›

2 syllabus objectives covered

State the components of blood and their roles in transport and defence: red blood cells, plasma, white blood cells, platelets.
List the different ABO blood groups and describe all possible combinations for donor and recipient in blood transfusions.

The Heart: Structure, Cardiac Cycle and Coronary Heart Disease›

3 syllabus objectives covered

Describe the structure and function of the heart in terms of muscular contraction and the working of valves.
Outline the cardiac cycle in terms of systole and diastole.
Describe coronary heart disease in terms of occlusion of coronary arteries, list possible causes and preventative measures.

Respiration in Humans

2 lessonsHuman Gas Exchange›

4 syllabus objectives covered

Identify the larynx, trachea, bronchi, bronchioles, alveoli and associated capillaries and state their functions in human gaseous exchange.
Describe the process of breathing and the role of cilia, diaphragm, ribs and intercostal muscles.
Explain how the structure of an alveolus is suited for its function of gaseous exchange.
State the major toxic components of tobacco smoke and describe their effects on health.

Cellular Respiration›

3 syllabus objectives covered

Define aerobic respiration and state the equation in words and symbols.
Define anaerobic respiration and state the word equation.
Explain why cells respire anaerobically during vigorous exercise resulting in an oxygen debt that is removed by rapid, deep breathing after exercise.

Excretion in Humans

1 lessonThe Kidneys: Structure, Function and Dialysis›

4 syllabus objectives covered

Define excretion and explain the importance of removing nitrogenous and other compounds from the body.
Identify the kidneys, ureter, bladder and urethra and state their functions in excretion.
Outline the function of the nephron with reference to ultra-filtration and selective reabsorption in the production of urine.
Outline the mechanism of dialysis in the case of kidney failure.

Homeostasis, Co-ordination & Response

3 lessonsPrinciples of Homeostasis›

3 syllabus objectives covered

Define homeostasis as the maintenance of a constant internal environment.
Explain the basic principles of homeostasis in terms of stimulus, corrective mechanism and negative feedback.
Describe the maintenance of constant body temperature in humans including the role of temperature receptors, sweating, shivering, blood flow changes and the hypothalamus.

Hormonal Control›

6 syllabus objectives covered

Define a hormone as a chemical substance produced by a gland, carried by the blood, which alters the activity of specific target organs.
Explain what is meant by an endocrine gland, with reference to the islets of Langerhans in the pancreas.
Explain how blood glucose concentration is regulated by insulin and glucagon as a homeostatic mechanism.
Describe type 2 diabetes mellitus in terms of high blood glucose due to insulin resistance or insufficient insulin.
Identify risk factors and ways to manage type 2 diabetes mellitus.
Outline the role of anti-diuretic hormone (ADH) in osmoregulation.

Nervous Control›

5 syllabus objectives covered

State that the nervous system – brain, spinal cord and nerves – serves to co-ordinate and regulate bodily functions.
Outline how receptors, sensory neurones, relay neurones, motor neurones and effectors work together to produce a co-ordinated response in a reflex action.
Describe the structure of the eye as seen in front view and in horizontal section.
State the principal functions of component parts of the eye in producing a focused image of near and distant objects on the retina.
Describe the pupil reflex in response to bright and dim light.

Infectious Diseases

1 lessonInfectious Diseases›

11 syllabus objectives covered

State that infectious diseases can be spread from person to person whereas non-infectious diseases cannot and identify examples of each.
Explain that infectious diseases are caused by pathogens such as bacteria and viruses and can be spread from person to person through body fluids, food and water.
State that a typical virus has a protein coat enclosing its genetic material and reproduces only in living host cells.
State that a typical bacteria cell has a cell wall and DNA without a nucleus; some are pathogenic and some non-pathogenic.
State the signs and symptoms of influenza and pneumococcal disease.
State that influenza is caused by the influenza virus.
State that pneumococcal disease is caused by the bacteria pneumococcus.
Describe the transmission and methods to reduce the transmission of influenza virus and pneumococcus.
State that vaccines contain an agent that resembles a pathogen and prevent infectious diseases by stimulating white blood cells to quickly produce antibodies when the pathogen invades.
Explain that antibiotics target bacteria by preventing synthesis of cellular structures but are ineffective against viruses due to structural and reproductive differences.
Discuss how the misuse and overuse of antibiotics may accelerate the emergence of antibiotic-resistant bacteria.

Nutrition & Transport in Plants

4 lessonsPlant Structure›

3 syllabus objectives covered

Identify the cellular and tissue structure of a dicotyledonous leaf as seen in transverse section using the light microscope and describe the significance of these features in terms of their functions, such as distribution of chloroplasts for photosynthesis, stomata and mesophyll cells for gaseous exchange, and vascular bundles for transport.
Identify the positions of and explain the functions of xylem vessels and phloem (sieve tube elements and companion cells) in sections of a herbaceous dicotyledonous leaf and stem under the light microscope.
Explain how the structure of a root hair cell is suited for its function of water and ion uptake.

Photosynthesis›

6 syllabus objectives covered

State that chlorophyll absorbs light energy and converts it into chemical energy for the formation of carbohydrates and their subsequent uses
Briefly explain why most forms of life are completely dependent on photosynthesis
State the equation, in words and symbols, for photosynthesis (light-dependent/independent detail not required)
Describe how carbon dioxide reaches mesophyll cells in a leaf
Investigate and discuss the effects of varying light intensity, carbon dioxide concentration and temperature on the rate of photosynthesis
Discuss light intensity, carbon dioxide concentration and temperature as limiting factors on the rate of photosynthesis

Transpiration›

2 syllabus objectives covered

Define the term transpiration and explain that transpiration is a consequence of gaseous exchange in plants.
Explain the movement of water between plant cells, and between them and the environment in terms of water potential (calculations on water potential are not required).

Transport in Plants: Water Transport and Translocation›

4 syllabus objectives covered

Outline the pathway by which water is transported into the roots and through the xylem vessels to the leaves by transpiration pull.
Investigate and explain the effects of variation of air movement, temperature, humidity and light intensity on transpiration rate.
Explain how wilting occurs.
Define translocation as the transport of food (mainly sucrose) in the phloem tissue and illustrate the process through translocation studies.

Organisms & their Environment (Ecology)

4 lessonsEnergy Flow›

2 syllabus objectives covered

Describe the non-cyclical nature of energy flow.
Explain how energy losses occur along food chains, and discuss the efficiency of energy transfer between trophic levels.

Food Chains and Food Webs›

2 syllabus objectives covered

Describe the roles of producers, consumers and decomposers in food chains and food webs.
Describe and interpret pyramids of numbers and biomass.

Carbon Cycle and Global Warming›

3 syllabus objectives covered

Describe how carbon is cycled within an ecosystem and outline the role of forests and oceans as carbon sinks.
Describe how human activities, such as deforestation and use of fossil fuels, cause an increase in atmospheric carbon dioxide concentration, leading to global warming.
Discuss how human actions can reduce the effects of global warming.

Human Impact on the Ecosystem and Conservation›

4 syllabus objectives covered

Describe the effects of pollution caused by sewage in water.
Describe the effects of pollution caused by plastic wastes in the marine environment.
Describe the effects of pollution caused by insecticides and their biomagnification up food chains, impacting on top carnivores.
Discuss how the conservation of species and sustainable use of natural resources contribute to the maintenance of biodiversity and a balanced ecosystem (e.g. coral reef, tropical rainforest, mangrove).

Molecular Genetics

2 lessonsThe Structure of DNA›

5 syllabus objectives covered

Outline the relationships among DNA, genes and chromosomes.
State that DNA is a double helix comprising two strands of nucleotides, each nucleotide formed of a sugar, a phosphate group and one of four different bases.
State the rule of complementary base pairing.
State that each gene is a sequence of nucleotides, as part of a DNA molecule, codes for one polypeptide, and is a unit of inheritance.
State that DNA is used to carry the genetic code, which is used to synthesise specific polypeptides (details of transcription and translation are not required).

Genetic Engineering›

3 syllabus objectives covered

State that genes may be transferred from the cells of one organism to the cells of another to form transgenic organisms.
Briefly explain how a gene that controls the production of human insulin can be inserted into bacterial DNA to produce human insulin in medical biotechnology.
Discuss the possible benefits and ethical considerations of genetic engineering, in medicine and production of economically important plants and animals.

Reproduction

5 lessonsAsexual Reproduction and Mitosis›

3 syllabus objectives covered

State that mitosis is a type of cell division giving rise to genetically identical cells in which the chromosome number is maintained.
State the importance of mitosis in growth, repair and asexual reproduction.
Define asexual reproduction as the process resulting in the production of genetically identical offspring from one parent.

Sexual Reproduction›

3 syllabus objectives covered

Define sexual reproduction as the process involving the fusion of nuclei of male and female gametes to form a zygote and the production of genetically dissimilar offspring.
Define the terms haploid and diploid, and explain the need for a reduction division process prior to fertilisation in sexual reproduction.
State what is meant by homologous pairs of chromosomes.

Meiosis›

2 syllabus objectives covered

State that meiosis is a type of cell division that gives rise to genetically dissimilar cells in which the chromosome number is halved due to the separation of homologous chromosomes.
State that meiosis is used in the formation of gametes.

Plant Reproduction›

6 syllabus objectives covered

Identify, using a hand lens if necessary, the sepals, petals, stamens and carpels of insect-pollinated, dicotyledonous flowers, and examine the pollen grains under a light microscope.
State the functions of the sepals, petals, anthers and carpels.
Identify, using a hand lens if necessary, the stamens and stigmas of wind-pollinated flowers, and examine the pollen grains under a light microscope.
Outline the process of pollination and distinguish between self-pollination and cross-pollination.
Compare, using fresh specimens, an insect-pollinated and a wind-pollinated flower and explain their differences.
Outline the growth of the pollen tube and its entry into the ovule followed by fertilisation.

Human Reproductive System›

7 syllabus objectives covered

Identify the male reproductive system and state the functions of: testes, scrotum, sperm ducts, prostate gland, urethra and penis.
Identify the female reproductive system and state the functions of: ovaries, oviducts, uterus, cervix and vagina.
Outline the menstrual cycle with reference to the alternation of menstruation and ovulation, the natural variation in its length, and the fertile and infertile phases of the cycle with reference to the effects of progesterone and oestrogen only.
Describe fertilisation and early development of the zygote simply in terms of the formation of a ball of cells which becomes implanted in the wall of the uterus.
State the functions of the amniotic sac and the amniotic fluid.
Describe the function of the placenta and umbilical cord in relation to exchange of dissolved nutrients, gases and excretory products.
Discuss the transmission of human immunodeficiency virus (HIV) and methods to reduce transmission.

Inheritance & Variation

4 lessonsThe Passage of Genetic Information from Parent to Offspring›

2 syllabus objectives covered

Distinguish between the terms gene and allele.
Explain the terms dominant, recessive, codominant, homozygous, heterozygous, phenotype and genotype.

Monohybrid Crosses›

5 syllabus objectives covered

Predict the results of simple crosses with expected ratios of 3:1 and 1:1, using the terms homozygous, heterozygous, F1 generation and F2 generation.
Explain why observed ratios often differ from expected ratios, especially when there are small numbers of progeny.
Use genetic diagrams to solve problems involving monohybrid inheritance.
Explain co-dominance and multiple alleles with reference to the inheritance of the ABO blood group phenotypes (A, B, AB, O) and the gene alleles (IA, IB and IO).
Describe the determination of sex in humans – XX and XY chromosomes.

Variation›

3 syllabus objectives covered

Describe mutation as a change in the sequence of a gene such as in sickle cell anaemia, or in the chromosome number, such as the 47 chromosomes in the condition known as Down syndrome.
Name ionising radiation (e.g. X-ray) and chemical mutagens as factors which may increase the rate of mutation.
Distinguish between continuous and discontinuous variation and give examples of each.

Natural Selection and Evolution›

3 syllabus objectives covered

State that variation and competition lead to differential survival of, and reproduction by, those organisms best fitted to the environment.
Give examples of environmental factors that act as forces of natural selection.
Explain the role of natural selection as a possible mechanism for evolution, which is a gradual change in the inheritable characteristics of a population over time.

Singapore O-Level Biology 6093 · complete syllabus coveragedistinction.study