B2.1 What plants need
Plants need air, water, light, heat, nutrients and space. Soil supplies water, nutrients and air in the gaps between its grains — soil is not food. Drought, frost, crowding, flooding and too little light can each threaten a plant.
Example
A seedling sits in a dark cupboard with water and rich soil. Predict what happens, and why.
- It grows pale and thin, then dies.
- It cannot make food without light, and soil is not food.
- Crowded seedlings compete for the same water, light and room — thin them out.
B2.2 Plant parts and their jobs
Example
Name each part and its job: root, stem, leaf.
- Root: anchors and takes in water and nutrients. Stem: holds the plant up; water travels up through tubes running its length. Leaf: makes the plant's food.
Example
Name each part and its job: flower, stamen, pistil.
- Flower: makes seeds. Stamen: the dusty-tipped stalk, makes pollen. Pistil: the flask shape, catches pollen and grows the seeds.
Example
Name each part and its job: seed, fruit, cone.
- Seed: a new plant, packed with food. Fruit: carries the seeds away from the parent. Cone: holds a conifer's seeds until the wind carries them.
B2.3 Plant life cycles
Example
Describe the life cycle of a bean and of a maple tree.
- Bean: seed → sprout, once water and warmth reach it in the soil → young plant → flower → pods of new seeds. Done in one summer.
- Maple: winged seed → seedling → sapling → tree that flowers and seeds each spring — for many years.
B2.4 Adaptations and reactions
Example
Explain how a cactus fits where it lives.
- Cactus: no leaves and a thick stem that stores water, so it survives long dry spells; spines keep animals from eating it.
Example
Explain how a water lily and a spruce fit where they live, and how a houseplant reacts to a window.
- Water lily: a flat pad floats so leaves reach light; a long stalk anchors in the mud. Spruce: downward-sloping branches shed snow; needles lose little water.
- Houseplant: its leaves turn toward the window — plants react to light.
B2.5 Photosynthesis
Example
Explain how a plant gets its energy.
- Leaves catch sunlight. With it, the plant makes food from water from the soil and a gas from the air — carbon dioxide.
- While it makes food, the plant gives off oxygen.
- This is photosynthesis. Most plants get their energy directly from the Sun this way.
B2.6 How people use plants
People, including Indigenous peoples, from cultures around the world use plants for food, shelter, medicine and clothing. Cotton and flax become cloth; cedar and bamboo become houses and boats; willow bark was used for pain long before pharmacies. People found out which plants worked by watching and testing over generations.
Example
Name a plant used for each: food, shelter, medicine, clothing.
- Food: wheat for bread; rice; corn.
- Shelter: cedar planks; birch bark over a frame; bamboo poles.
- Medicine: willow bark for pain. Clothing: cotton and flax fibres spun into thread.
B2.7 Food plants grown and gathered here
Many food plants are grown or gathered in Ontario, including those grown by First Nations, Métis, and Inuit. Corn, beans and squash are planted in fields and gardens. Blueberries, wild rice, maple sap and fiddleheads have long been gathered rather than farmed — in bogs, lakes, sugar bushes and spring woods.
Example
Name which plant part we eat: carrot, potato, broccoli, lettuce, peas, celery. Then describe how maple syrup is made.
- Carrot: root. Potato: underground stem. Broccoli: flower buds. Lettuce: leaves. Peas: seeds. Celery: stalk.
- Warm days and freezing nights start the sap moving; drill the tree and collect it.
- Boil for hours until nearly all the water is gone — syrup.
B2.8 Plants, animals and people depend on each other
Example
Explain what happens in an orchard with no bees, and what happens to fallen leaves by spring.
- No bees: without pollen carried between the flowers, few fruits can form.
- Fallen leaves: worms, fungi and tiny living things break them down into soil, which feeds next year's plants.
Summary
- Air, water, light, heat, nutrients, space — soil is not food.
- Root, stem, leaf, flower (stamen, pistil), seed, fruit, cone.
- Seed → sprout → plant → flower, on different clocks.
- Adaptations fit the place; plants react to light.
- Photosynthesis: sunlight, water and carbon dioxide → food, oxygen out.
- Plants clothe, house, heal and feed us; we all depend on each other.