Plants Demonstrations

Plant demonstrations highlight how plants grow, respond to their environment, and sustain life. These activities remind students that plants, though often overlooked, can reveal striking biological processes.

Demonstration	Materials	Difficulty	Safety	Summary
Fruit Dissection	★☆☆	★★☆	★☆☆	By dissecting a variety of fruits, students can explore their internal and external structures, recognize similarities among them, and connect these observations to plant reproduction and their origins as flowers.
Celery Capillary Action	★☆☆	★☆☆	★☆☆	Celery is placed in colored water and the colors move upwards to it's leaves.
Limp Celery	★☆☆	★☆☆	★☆☆	Celery pieces are soaked in salt water and fresh water to show how water moves in or out of plant cells by osmosis, changing texture from rigid to limp.
Leaf Chromatography	★★☆	★★☆	★★☆	Chromatography is used to separate pigments in green leaves. By dissolving leaf pigments in alcohol and drawing them up filter paper, students can see hidden colors like carotenoids and anthocyanins that are usually masked by chlorophyll.
Measuring Oxygen Use by Germinating Seeds	★★☆	★★☆	★☆☆	Germinating seeds use oxygen and release carbon dioxide during respiration. Using a respirometer with limewater and detergent, oxygen consumption can be measured by observing the movement of a liquid drop inside a sealed tube.
Exploding Seed Pod Model	★☆☆	★☆☆	★☆☆	In this activity, students build a model of an exploding seed pod using balloons filled with bird seed. When the balloon is popped, the seeds scatter, simulating how plants use mechanical adaptations to disperse seeds away from the parent plant.
Phototropism Plant Light Maze	★☆☆	★☆☆	★☆☆	In this activity, students investigate phototropism - the ability of plants to grow toward light, by designing a shoebox maze with obstacles. A sprouting bean plant is placed inside, and students observe whether it can bend and grow around barriers to reach a light source. This experiment demonstrates how plants use light for photosynthesis and adapt their growth to their environment.
Gravitropism in Seedling Stalks	★★☆	★☆☆	★☆☆	In this demonstration, seedling stalks (hypocotyls) are placed horizontally in dark containers, and within about an hour they begin to bend upward, showing negative gravitropism. This illustrates how plants sense gravity and redirect growth through hormonal signaling.
Leaf Disk Photosynthesis	★★☆	★★☆	★☆☆	In this investigation, leaf disks are vacuum-infiltrated with a baking soda solution so they sink. When exposed to light, oxygen from photosynthesis causes the disks to float, and the time until half of them float (ET50) indicates the photosynthesis rate.
Test for Starch in Leaves	★★☆	★★☆	★★☆	Leaves from a plant kept in light and one kept in darkness are boiled briefly, decolorized in hot ethyl alcohol, and stained with iodine. A blue-black color indicates starch, showing that photosynthesis in light produced stored carbohydrate.
Flower Dissection	★★☆	★☆☆	★★☆	Students carefully take apart several fresh flowers to identify and compare major plant structures (stem, leaves, petals, stamen, pistil) and relate those parts to pollination and seed formation. Parts are sorted and labeled to compare within a species and across different flowers.
Ecosystem in a Bottle	★☆☆	★☆☆	★☆☆	Students create a self-contained bottle ecosystem using soil, rocks, seeds, and water. This hands-on activity models how living and nonliving components interact in ecosystems and illustrates the role of plants and the water cycle in maintaining balance.
Genetic Inheritance in Brassica rapa	★★★	★★☆	★☆☆	Students investigate Mendelian inheritance in Brassica rapa by studying two traits: stem height (tall vs. dwarf) and stem color (purple vs. green). They grow F1 and F2 generations, predict outcomes with Punnett squares, then compare predictions with actual phenotypic ratios using class data.
Asexual Propagation in Plants	★★☆	★☆☆	★☆☆	Students learn about asexual plant propagation by taking cuttings from stock plants, rooting them in water or soil, and comparing their growth. The activity demonstrates how new plants can be cloned from parent plants without seeds.
Bubbling Plants: Quantifying Photosynthesis	★★★	★★☆	★☆☆	Students place Elodea in baking-soda water and count gas bubbles produced in low light and bright light for fixed time intervals. Comparing bubble counts provides an indirect, simple measure of photosynthesis under different light intensities.
Observing Plant Transpiration	★☆☆	★☆☆	★☆☆	This demonstration shows how plants release water vapor through their leaves in a process called transpiration. By sealing leaves inside a plastic bag and comparing it with a control bag, students can observe condensation forming as water vapor escapes from stomata and condenses on the bag’s surface.
Onion Root Tip Mitosis	★★☆	★★☆	★☆☆	This experiment demonstrates mitosis by preparing and observing stained onion root tip cells under a compound microscope. Students identify the stages of mitosis while understanding why onion root tips are suitable for studying active cell division.
Seed Dispersal	★★☆	★☆☆	★☆☆	This experiment uses real seeds and household items to model four main methods of seed dispersal: wind, water, animals, and mechanical bursting. Students test how different seeds travel and connect adaptations to plant survival strategies.
Factors Affecting Seed Germination	★☆☆	★☆☆	★☆☆	Use a clear jar with damp paper towels and common bean seeds to test how water, temperature, light, and air (oxygen) affect germination. Students set up controlled comparisons and record when and how well seeds sprout.

Materials
★☆☆ Easy to get from supermarket or hardware store
★★☆ Available in most school laboratories or specialist stores
★★★ Requires materials not commonly found in school laboratories

Difficulty
★☆☆ Can be easily done by most teenagers
★★☆ Available in most school laboratories or specialist stores
★★★ Requires a more experienced teacher

Safety
★☆☆ Minimal safety procedures required
★★☆ Some safety precautions required to perform safely
★★★ Only to be attempted with adequate safety procedures and trained staff