B2.1 Classifying organisms
Example
Name the distinguishing characteristics of mammals, birds and fish.
- Mammals: hair or fur on the body, and milk to feed the young. Birds: feathers covering the body, and a beak for feeding. Fish: gills and fins, for a whole life spent in water.
Example
Name the distinguishing characteristics of insects, amphibians and reptiles.
- Insects: six legs, and a body built in three distinct parts. Amphibians: smooth damp skin, and a start to life in the water. Reptiles: dry scales covering the whole of the body.
Example
Classify the robin, frog and beetle.
- Robin — bird; frog — amphibian; beetle — insect. To classify is to sort living things into groups by shared features.
B2.2 What biodiversity is
Example
Explain what biodiversity, species and habitat mean.
- Biodiversity: the full variety of living things a place holds. Species: one kind of living thing, able to have young together. Habitat: the place where a living thing finds its food and shelter.
Example
Give the three levels at which variety can be counted.
- Within a species: the different coat colours in one kind of beetle. Among species in a community: the many kinds in one pond.
- Among communities and their habitats: pond, meadow, forest, side by side.
B2.3 Variety within a species
Example
Explain why a beetle species with several colours, and a deer population with varied coats, survive a change better.
- Whichever colour hides better where it sits, some beetles escape notice — so the kind carries on.
- In a hard winter, the thicker-coated ones are likelier to come through it, and their young inherit what got them through.
B2.4 Variety and resilience
Example
Compare a many-kinds pond with a one-kind pond after a blight.
- Resilience is how well a community bounces back after harm or change.
- The many-kinds pond — its other plants spread into the space and keep the pond's life fed and sheltered; the one-kind pond has nothing to spread.
Example
Explain why a mixed forest keeps standing after a beetle kills one tree kind.
- The forest's other tree kinds are untouched by that beetle, so the canopy and its shelter carry on around the gaps.
B2.5 Interrelationships that sustain biodiversity
Example
Describe the relationship between a bee and clover and an owl and mice, and say how each sustains variety.
- Bee and clover: the bee carries food away, and the clover gets its pollen moved so it can set seed.
- Owl and mice: it keeps the mouse numbers from outgrowing the seeds and shelter the hedgerow holds.
Example
Describe the relationship between worms and soil, and say how it sustains variety.
- Worms and soil: the leaves break down into nutrients in the soil, which the plants' roots then draw on. Each link keeps others in place.
B2.6 Invasive species
Example
Define invasive, and explain why an invasive plant's numbers grow.
- Invasive means brought from elsewhere, spreading hard and harming what already lives there. With nothing eating it, its numbers grow unchecked in a way they never could at home.
Example
Explain how the invasive plant reduces the variety of a local wood.
- It takes the native plants' light and their ground, so fewer of them come up each spring; their food and cover thin out with the plants, so fewer of those animals can live there.
Example
Explain how it got there, and why that matters.
- Boats travel lake to lake, so the same ride that brought it here can carry it onward.
B2.7 Climate change and biodiversity
Example
Explain how a warming climate affects polar bears on sea ice and trout in a stream.
- Ice: their hunting and resting ground shrinks season by season, so fewer can feed and raise young there.
- Stream: their stretch of liveable water shrinks toward the cold headwaters, and the stream holds fewer of them.
Example
Explain how a warming climate affects migrating birds and caterpillars.
- Timing: the birds arrive after the caterpillar peak has passed, so there is less food just when the chicks need most.
B2.8 Biodiversity and agriculture, including Indigenous agriculture
Farms depend on variety. Bees carry pollen among the blossoms, and a pollinated blossom is what becomes a fruit. A farm growing four kinds of potato loses one kind to a blight — the other three kinds stand untouched, so most of the harvest still comes in.
Haudenosaunee and other First Nations farmers plant the Three Sisters — corn, beans and squash — together in one mound. Each crop works for the others — the corn holds the beans up, the beans feed the soil, and the squash leaves shade out weeds and keep the ground moist.
Example
Explain how chinampas — raised field beds the Nahua farmers built in the Valley of Mexico, still farmed at Xochimilco today — yielded all year.
- The surrounding water kept the beds moist from below, and the lake mud layered into them kept the soil rich — so the fields yielded all year.
Summary
- Six groups, six traits.
- Variety within species, among species, among communities.
- Varied populations survive change; varied communities bounce back.
- Links between species hold each other in place.
- Invasives spread unchecked; warming shrinks ranges and shifts timing.
- Farms depend on pollinators, crop variety, and cooperative planting.