19 experiments found
Clear filtersInvertebrates have no backbone; they are grouped by their body plan, such as jointed legs (arthropods), a soft body often with a shell (molluscs) or a body of rings (annelids)
Look at the body, the legs and the covering of fifteen invertebrates, from butterflies and crabs to snails, leeches and starfish, then sort them into their groups.
Plant and animal cells both have a nucleus, cytoplasm, cell membrane and mitochondria; only plant cells have a cell wall, chloroplasts and a large central vacuole
Label the parts of a plant cell and an animal cell, find out what each part does, and discover which parts only plant cells have.
Organs that work together to do one big job form a body system, such as the digestive system, which breaks down food
Find sixteen organs on the body, read what each one does, and sort them into the digestive, respiratory, circulatory, nervous, excretory and skeletal systems.
Organisms have adaptations, special features that help them survive in their habitat
Study the body features of plants and animals, from a yak to a lotus, and match each one to the habitat it is adapted to.
Water travels up the stem in xylem tubes, pulled by water evaporating from the leaves
Stand celery stalks in red-dyed water, with and without leaves, in a warm sunny place and a cool shady one, and track how high the dye climbs.
Plants use light energy to make glucose from carbon dioxide and water, giving off oxygen; light, carbon dioxide and temperature can each limit the rate
Shine a lamp on pondweed and count the oxygen bubbles. Change the light distance, the light colour, the carbon dioxide and the temperature to find what limits photosynthesis.
Stomata are tiny pores, mostly on the underside of leaves, opened and closed by a pair of guard cells to let gases in and out and control water loss
Look at a peel from the underside of a leaf under the microscope and label the epidermal cells, guard cells, chloroplasts and open and closed stomata.
Plants lose water vapour through stomata in their leaves; it is faster in warm, bright, windy and dry conditions
Stand a leafy shoot in water under a plastic bag and measure how much water it loses in light and dark, still and windy, dry and humid air, and with its leaves greased.
Many plants make new plants from a stem, a root or a leaf, without seeds; this vegetative propagation gives plants exactly like the parent, quickly
Find which part of twelve plants, from potato, ginger and sugarcane to sweet potato and bryophyllum, is planted to grow a new plant, and sort them by stem, root or leaf.
Body mass index compares mass with height: BMI = mass (kg) ÷ height² (m²); for adults 18.5 to under 25 is a healthy range, but children are still growing, so their BMI is checked on charts for their age and sex
Choose a mass and a height and work out the body mass index, BMI = mass ÷ height². See which adult band it falls in, and learn why doctors use age charts, not these bands, for growing children.
Energy used (kcal) ≈ MET × body mass (kg) × time (hours), where the MET says how many times harder than resting an activity is; harder play, a heavier body and longer play all use more energy
Choose a game or exercise, your body mass and how long you play, and work out how much food energy your body uses, in kilocalories and in rotis.
First aid is the help given before a doctor arrives: it keeps the person safe, stops things getting worse and gets them to proper care; some common habits, like ice on burns or sucking snake venom, harm or waste precious time
Twelve things people do for burns, cuts, nosebleeds, snake and dog bites, diarrhoea and someone who has fainted. Find out why each helps or harms, and sort the good first aid from the old habits that do damage.
Each case of a disease infects R₀ people when no one is immune; when more than 1 − 1/R₀ of people are vaccinated, each case infects fewer than one other and the disease dies out, protecting even those who cannot be vaccinated
Choose a disease, from flu to measles, and how many people in a town are vaccinated. See how many people each case infects now, how many must be vaccinated for herd immunity, and whether the disease dies out or keeps spreading.
Bacteria multiply by splitting in two; in warm food they can double every 20 minutes, so after n doublings one germ becomes 2ⁿ, which grows faster and faster
Start with one germ on a plate of food left out in the warm. Choose how often it doubles and how many hours pass, and watch one germ become thousands, then millions, which is why cooked food should not sit out for long.
The body loses water in sweat, breath and urine, so a child needs about 35 mL of water for every kg of body mass each day, more when playing hard and on hot days
Choose a body mass, the minutes of hard play and whether it is a hot day, and work out how much water a child needs in a day, in millilitres and in glasses.
Inherited traits are set by genes passed from parents to children; acquired traits are learnt or gained during life, from practice, injury or the surroundings, and are not passed on in the genes
Look at twelve traits, from eye colour and dimples to a scar, a suntan and the language you speak. Find where each comes from and whether your children could get it from you, then sort them into inherited and acquired traits.
A lack of one nutrient causes a deficiency disease: vitamin A night blindness, vitamin C scurvy, vitamin D rickets, vitamin B1 beriberi, iron anaemia and iodine goitre; foods rich in that nutrient prevent it
Twelve cards show a sign of poor diet, such as night blindness or a swollen neck, or a food that prevents one, such as carrots or iodised salt. Find out what each tells you, then sort them by the vitamin or mineral they are about.
Red cells may carry A, B and Rh antigens; a patient's blood attacks any A or B it lacks, and an Rh-negative patient reacts to Rh, so O− can give to everyone and AB+ can take from everyone
Check twelve donor and patient pairs, from O− to A+ and AB+ to O−. Find the antigens on the donor's red cells and the antibodies in the patient's blood, and sort each transfusion as safe or not safe.
Plants cannot move, so they spread their seeds away from the parent plant by wind, water, animals or bursting pods, and each seed or fruit has a shape that suits its way of travelling
Look closely at twelve seeds and fruits, from the dandelion's parachute to the coconut's husk and the burr's hooks, and sort them by how they travel: by wind, by water, by animals or by bursting pods.