Grade 11 Science: Biology

In this unit, 'The living world and biological classification', you learn to classify organisms using taxonomy. You work with exam-style questions and written reasoning. You see it, say it, then do it alone.

• Observe: see, touch, measure or watch a safe demonstration linked to 'The living world and biological classification' and write what you notice.
• Explain: use the key words of the unit to say what is happening and why, in a few lines.
• Use it: classify organisms using taxonomy. Use a diagram, table or short calculation where it fits.
• Test and conclude: say what evidence supports your answer and what you would change.

Step by step.

1. Step 1, Classify using the five-kingdom system, which sorts living things by cell type, body organisation and mode of nutrition. Monera: bacteria, prokaryotic. Protista: single-celled eukaryotes such as Amoeba. Fungi: absorb food, cell wall of chitin. Plantae: make food by photosynthesis. Animalia: eat food, no cell wall. Place a mushroom: Fungi.
2. Step 2, Learn the taxonomic hierarchy from largest to smallest group: Kingdom, Phylum (Division in plants), Class, Order, Family, Genus, Species. Each step down has fewer organisms that share more features. A handy memory line is built from the first letters K P C O F G S. Species is the basic unit: organisms that can breed together.
3. Step 3, Classify the lion: Kingdom Animalia, Phylum Chordata, Class Mammalia, Order Carnivora, Family Felidae, Genus Panthera, species leo. Check each rung: it has a backbone (Chordata), hair and milk glands (Mammalia), and meat-eating teeth (Carnivora). The domestic cat shares the same Class, Order and Family.
4. Step 4, Write the scientific name by binomial nomenclature: genus first with a capital letter, species second in lower case, and the whole name in italics or underlined when handwritten. Examples: Homo sapiens for human, Mangifera indica for mango, Panthera leo for lion. The two-part name is the same worldwide.
5. Step 5, Classify the mango tree: Kingdom Plantae, Division Angiospermae, Class Dicotyledonae, Order Sapindales, Family Anacardiaceae, Genus Mangifera, species indica. Explain why: it makes seeds inside fruits (angiosperm) and its seed has two cotyledons (dicot). Different plants in the genus share the name Mangifera.
6. Step 6, Your turn: the domestic cat is Felis catus. Name its genus, species, family and order, and say what it shares with the lion. Answer: genus Felis, species catus, family Felidae, order Carnivora. It shares Family Felidae, Order Carnivora, Class Mammalia, Phylum Chordata and Kingdom Animalia with the lion.

Activity. About 40 to 50 minutes of class work, then one short practice task for home. Keep evidence: a timed paper and an error log.

Standard to meet. Classify organisms using taxonomy: at least 70 percent on an exam-style task, with the method shown.

In this unit, 'Plant kingdom and animal kingdom', you learn to compare major plant and animal groups. You work with exam-style questions and written reasoning. You see it, say it, then do it alone.

• Observe: see, touch, measure or watch a safe demonstration linked to 'Plant kingdom and animal kingdom' and write what you notice.
• Explain: use the key words of the unit to say what is happening and why, in a few lines.
• Use it: compare major plant and animal groups. Use a diagram, table or short calculation where it fits.
• Test and conclude: say what evidence supports your answer and what you would change.

Step by step.

1. Step 1, Compare the five main plant groups. Algae: simple, mostly aquatic, for example Spirogyra. Bryophytes: moss and liverworts, no vascular tissue. Pteridophytes: ferns, vascular tissue but no seeds. Gymnosperms: Cycas and Pinus, seeds not enclosed in fruit. Angiosperms: flowering plants with seeds inside fruits.
2. Step 2, Compare bryophytes and pteridophytes. Both need water for the male gamete to swim to the egg. Moss has no true roots, only root-like rhizoids, and no xylem or phloem. A fern has true roots, stems, leaves and vascular tissue, so it can grow taller. Neither produces seeds; both spread by spores.
3. Step 3, Compare gymnosperms and angiosperms. Pine seeds sit naked on cone scales, while mango seeds are covered by a fruit. Angiosperms are divided into monocots (one seed leaf, parallel veins, fibrous roots, as in wheat) and dicots (two seed leaves, net veins, tap root, as in gram).
4. Step 4, Compare animal phyla by body plan. Porifera (sponges) have pores, no true tissues. Cnidaria (Hydra) have stinging cells and radial symmetry. Platyhelminthes (tapeworm) are flat. Annelida (earthworm) have ringed segments. Arthropoda (cockroach) have jointed legs and the most species. Mollusca (snail) have soft bodies. Echinodermata (starfish) have spiny skins.
5. Step 5, Compare the vertebrate classes by the heart. Pisces (fish) have gills and a 2-chambered heart. Amphibia (frog) have moist skin and a 3-chambered heart. Reptilia (lizard) have dry scales and usually a 3-chambered heart. Aves (sparrow) have feathers and a 4-chambered heart. Mammalia (human) have hair, milk glands and a 4-chambered heart.
6. Step 6, Your turn: compare a frog and a sparrow in four points: class, heart, skin or body covering, and body temperature. Answer: frog is Amphibia, 3-chambered heart, moist skin, cold-blooded; sparrow is Aves, 4-chambered heart, feathers, warm-blooded. Both are chordates with a backbone.

Activity. About 40 to 50 minutes of class work, then one short practice task for home. Keep evidence: a timed paper and an error log.

Standard to meet. Compare major plant and animal groups: at least 70 percent on an exam-style task, with the method shown.

In this unit, 'Structural organisation and cell: the unit of life', you learn to describe tissues and cell structure. You work with exam-style questions and written reasoning. You see it, say it, then do it alone.

• Observe: see, touch, measure or watch a safe demonstration linked to 'Structural organisation and cell: the unit of life' and write what you notice.
• Explain: use the key words of the unit to say what is happening and why, in a few lines.
• Use it: describe tissues and cell structure. Use a diagram, table or short calculation where it fits.
• Test and conclude: say what evidence supports your answer and what you would change.

Step by step.

1. Step 1, Describe the cell. All living things are made of cells, cells come from existing cells, and the cell is the basic unit. A prokaryotic cell (bacteria) has no membrane-bound nucleus. A eukaryotic cell (plant, animal) has a nucleus and organelles. Typical animal cells measure about 10 to 30 micrometres, and one micrometre is a thousandth of a millimetre.
2. Step 2, Describe the organelles. The cell membrane controls what enters and leaves. The nucleus holds DNA. Mitochondria release energy as ATP. Ribosomes make proteins. The endoplasmic reticulum transports materials, the Golgi body packs and sends them, and lysosomes digest waste. Write one job beside each name.
3. Step 3, Describe the differences between plant and animal cells. A plant cell has a cellulose cell wall outside the membrane, chloroplasts for photosynthesis and a large central vacuole. An animal cell has none of these but usually has centrioles, which help in cell division. Both have a nucleus, mitochondria and ribosomes.
4. Step 4, Describe the four animal tissues. Epithelial tissue covers surfaces, such as the flat cells lining the air sacs. Connective tissue joins and supports: bone, cartilage and blood. Muscular tissue contracts: skeletal, smooth and cardiac. Neural tissue carries signals through neurons. Plant tissues are meristematic (dividing) or permanent.
5. Step 5, Calculate magnification when you view a slide. Magnification = image size divided by actual size. A red blood cell about 7 micrometres wide is drawn 14 mm wide: 14 mm = 14,000 micrometres, and 14,000 / 7 = 2,000, so the drawing is magnified 2000 times. Safety: glass slides and coverslips are fragile, stains such as iodine stain skin and clothes, and hands are washed afterwards.
6. Step 6, Your turn: a cheek cell is 60 micrometres wide and your drawing is 30 mm wide. Find the magnification. Answer: 30 mm = 30,000 micrometres; 30,000 / 60 = 500, so the magnification is 500 times. Also say which organelle is absent from a cheek cell but present in a leaf cell: the chloroplast.

Activity. About 40 to 50 minutes of class work, then one short practice task for home. Keep evidence: a timed paper and an error log.

Standard to meet. Describe tissues and cell structure: at least 70 percent on an exam-style task, with the method shown.

In this unit, 'Cell cycle and biomolecules', you learn to explain mitosis, meiosis and biomolecules. You work with exam-style questions and written reasoning. You see it, say it, then do it alone.

• Observe: see, touch, measure or watch a safe demonstration linked to 'Cell cycle and biomolecules' and write what you notice.
• Explain: use the key words of the unit to say what is happening and why, in a few lines.
• Use it: explain mitosis, meiosis and biomolecules. Use a diagram, table or short calculation where it fits.
• Test and conclude: say what evidence supports your answer and what you would change.

Step by step.

1. Step 1, Follow the cell cycle: interphase (G1, S with DNA replication, G2) then M phase. In a 24 hour cycle, interphase takes about 23 hours and mitosis about 1 hour. A cell with 46 chromosomes copies its DNA in S phase.
2. Step 2, Describe mitosis: prophase (chromosomes condense), metaphase (align at the plate), anaphase (sister chromatids separate), telophase (nuclei form), and then cytokinesis. One 2n = 46 cell gives two cells with 46 chromosomes each.
3. Step 3, Describe meiosis. Meiosis I separates homologous chromosomes with crossing over in prophase I, giving two cells with 23 chromosomes. Meiosis II separates chromatids, giving four haploid cells. Variation arises by crossing over and independent assortment.
4. Step 4, Count. Mitosis: 1 cell to 2 cells, DNA content 4C in G2 to 2C each. Meiosis: 1 cell to 4 cells, each with 1C. A human sperm cell has 23 chromosomes, and fertilisation restores 46.
5. Step 5, Cover biomolecules. Carbohydrates: glucose C6H12O6, starch, cellulose. Proteins: amino acids joined by peptide bonds. Lipids: glycerol and fatty acids. Nucleic acids: DNA with bases A, T, G, C. Enzymes lower activation energy.
6. Step 6, Your turn: a plant cell with 2n = 20 undergoes meiosis. How many chromosomes in each gamete cell and how many cells result? Answer: 10 chromosomes, 4 cells.

Activity. About 40 to 50 minutes of class work, then one short practice task for home. Keep evidence: a timed paper and an error log.

Standard to meet. Explain mitosis, meiosis and biomolecules: at least 70 percent on an exam-style task, with the method shown.

In this unit, 'Plant physiology', you learn to describe photosynthesis, respiration and plant growth. You work with exam-style questions and written reasoning. You see it, say it, then do it alone.

• Observe: see, touch, measure or watch a safe demonstration linked to 'Plant physiology' and write what you notice.
• Explain: use the key words of the unit to say what is happening and why, in a few lines.
• Use it: describe photosynthesis, respiration and plant growth. Use a diagram, table or short calculation where it fits.
• Test and conclude: say what evidence supports your answer and what you would change.

Step by step.

1. Step 1, Describe photosynthesis with the balanced equation: 6CO2 + 6H2O gives C6H12O6 + 6O2, using light and chlorophyll. Count atoms to check: both sides have 6 carbon, 12 hydrogen and 18 oxygen. Carbon dioxide enters through stomata, water arrives through roots, glucose feeds the plant and oxygen is released.
2. Step 2, Describe the two stages. The light reaction happens in the grana of the chloroplast: light splits water, releasing oxygen and making ATP and NADPH. The dark reaction (Calvin cycle) happens in the stroma: carbon dioxide is fixed into sugar using that ATP and NADPH. Light is needed directly only for the first stage.
3. Step 3, Describe respiration: glucose + 6O2 gives 6CO2 + 6H2O + energy. Glycolysis takes place in the cytoplasm and splits one glucose into 2 pyruvate with a net gain of 2 ATP. The Krebs cycle runs in the mitochondrial matrix, and the electron transport chain on the inner membrane makes most of the ATP. Textbooks quote totals of roughly 30 to 38 ATP per glucose, so check the figure your course uses.
4. Step 4, Describe plant growth and its regulators. Auxins promote cell elongation and make stems bend toward light. Gibberellins make stems elongate and break seed dormancy. Cytokinins promote cell division. Abscisic acid closes stomata in drought. Ethylene ripens fruit. Growth is measured by increase in height, mass or number of cells.
5. Step 5, Describe the starch test for photosynthesis. Take a leaf kept in light, boil it in water for a minute, then warm it in ethanol in a hot water bath to remove chlorophyll, and add iodine. Blue-black means starch is present. Safety: ethanol is flammable, so never heat it over a flame; use hot water, wear goggles, and keep iodine off the skin.
6. Step 6, Your turn: if a plant makes 3 molecules of glucose, how many molecules of carbon dioxide are used and oxygen released? Answer: 6 CO2 gives 1 glucose, so 3 glucose need 18 CO2 and release 18 O2 (6 x 3 for each). In respiration the same 18 O2 would be needed to break the sugar down.

Activity. About 40 to 50 minutes of class work, then one short practice task for home. Keep evidence: a timed paper and an error log.

Standard to meet. Describe photosynthesis, respiration and plant growth: at least 70 percent on an exam-style task, with the method shown.

In this unit, 'Human physiology', you learn to describe digestion, breathing, circulation and excretion. You work with exam-style questions and written reasoning. You see it, say it, then do it alone.

• Observe: see, touch, measure or watch a safe demonstration linked to 'Human physiology' and write what you notice.
• Explain: use the key words of the unit to say what is happening and why, in a few lines.
• Use it: describe digestion, breathing, circulation and excretion. Use a diagram, table or short calculation where it fits.
• Test and conclude: say what evidence supports your answer and what you would change.

Step by step.

1. Step 1, Describe digestion. In the mouth, salivary amylase starts breaking starch into sugars. In the stomach, acid of about pH 1.5 to 2 and the enzyme pepsin begin digesting protein. In the small intestine, bile, lipase and trypsin finish fats and proteins, and villi absorb the nutrients into the blood. Undigested matter leaves via the large intestine.
2. Step 2, Describe breathing. The diaphragm contracts and flattens, the ribs move up and out, chest volume rises, pressure falls and air flows in. In the alveoli oxygen diffuses into blood and carbon dioxide leaves. A resting adult takes in about 500 mL per breath (tidal volume) at roughly 12 breaths per minute: 500 x 12 = 6,000 mL, or 6 litres per minute.
3. Step 3, Describe circulation. The heart has four chambers. Deoxygenated blood enters the right atrium, goes to the right ventricle, then to the lungs. Oxygenated blood returns to the left atrium, enters the left ventricle and is pumped to the body. This double circulation keeps oxygen-rich and oxygen-poor blood apart.
4. Step 4, Describe the output of the heart. If each beat pumps about 70 mL (stroke volume) and the pulse is 72 beats per minute, then 70 x 72 = 5,040 mL, about 5 litres per minute. That is roughly the volume of blood in the whole body, so all of it passes the heart about once every minute.
5. Step 5, Describe excretion. Each kidney has about a million nephrons. Blood is filtered in the glomerulus to give roughly 180 litres of filtrate a day, but most water and useful solutes such as glucose are reabsorbed, so only about 1.5 litres of urine is made. Urea and extra salts leave, and urine passes through the ureters to the bladder.
6. Step 6, Your turn: a person breathes 450 mL per breath at 14 breaths a minute. Find the volume of air per minute, then name the muscle that pulls air in. Answer: 450 x 14 = 6,300 mL, which is 6.3 litres per minute. The muscle is the diaphragm, helped by the muscles between the ribs.

Activity. About 40 to 50 minutes of class work, then one short practice task for home. Keep evidence: a timed paper and an error log.

Standard to meet. Describe digestion, breathing, circulation and excretion: at least 70 percent on an exam-style task, with the method shown.

On the slide: L1 Basic · Living or not living

Notes: Name the signs of life, such as movement, feeding, growth and reproduction, and sort everyday things into living and non-living. Notes: collect ten objects or pictures, such as a pebble, a leaf and a toy; learners sort them and give one reason for each choice. Wash hands after touching soil or plants.

On the slide: L2 Awareness · Cells and the microscope

Notes: Describe the main parts of plant and animal cells and say what a microscope does. Notes: practise magnification with eyepiece 10 times and objective 40 times, which gives 400 times. Carry the microscope with two hands and never point it at the sun.

On the slide: L3 Foundation · Photosynthesis and respiration

Notes: Explain photosynthesis and respiration and write the word and symbol equations. Notes: learners check 6CO2 + 6H2O gives C6H12O6 + 6O2 balances by counting atoms. For a leaf starch test, soften the leaf in hot water, never in a flame near ethanol, and wear goggles.

On the slide: L4 Practitioner · Enzyme rate investigation

Notes: Apply the idea of rate to plan and run a fair enzyme test. Notes: practice case is starch gone in 40 s at 20 C and 20 s at 30 C. Rate is 1/time, so 0.025 and 0.05 per second, a doubling. Learners name three controlled variables and one hazard.

On the slide: L5 Specialist · Genetics and chi-squared

Notes: Analyse monohybrid crosses and test results against the expected ratio. Notes: Tt crossed with Tt expects 3 to 1, so 120 tall and 40 short from 160 offspring. Observed 112 and 48 gives chi-squared 2.13, below 3.84 at 5 per cent with one degree of freedom, so no significant difference.

This course: Grade 11 Science Biology is at this level. Its units include The living world and biological classification; Plant kingdom and animal kingdom; Structural organisation and cell: the unit of life; Cell cycle and biomolecules and more.

On the slide: L6 Advanced · Population genetics and molecular tools

Notes: Apply Hardy-Weinberg and molecular reasoning to predict allele and genotype frequencies. Notes: if 4 per cent of people show a recessive trait, q squared is 0.04, so q is 0.2 and p is 0.8; carriers are 2pq, which is 32 per cent. Learners list the five assumptions and test which one fails.

On the slide: L7 Super expert · Design and critique a genomic study

Notes: Evaluate and create an experiment with sound sampling, controls, ethics and multiple-testing correction. Notes: testing 20,000 genes at the 5 per cent level gives about 1,000 false positives by chance, so use false discovery rate control. Learners write a pre-registered plan and list biosafety and consent approvals.