Living things and a changing environment
How much feed is too much feed?
Does doubling the plant food double the growth, or harm it?
Watch first
An English teaching video on this topic from MightyOwl. Watch it, then scroll down for the lesson.
What you need
Tick each one as you find it — 0 of 7 ready.
Stay safe: Wash your hands after handling compost and plant feed.
Plan the fair test
- Change: The strength of the plant feed
- Measure: Shoot height in mm
- Keep the same: Seed type and number, pot size, volume of solution, light and temperature
Objectives this evidences
- Understand how organisms affect, and are affected by, their environment, including the accumulation of toxic materials
- Understand changes in the environment that may leave individuals within a species, and some entire species, less well adapted to compete successfully and reproduce, which in turn may lead to extinction
Do it, one step at a time
Step 1 of 4
- Step 1. Set up four identical pots with the same amount of cotton wool or compost and the same number of seeds. Label them A, B, C and D.
- Step 2. Mix the feed at four strengths: A gets plain water, B gets the dose on the bottle, C gets double, D gets four times.
- Step 3. Give each pot the same volume of its solution every day and keep them all on the same windowsill.
- Step 4. Measure the tallest shoot in each pot every two days for ten days, then plot height against day for all four pots on one graph.
What should happen
A normal dose grows fastest. Too much feed damages the roots, so the strongest pots often do worst.
Think about: Farmers face the same trade-off in rivers: run-off fertiliser changes whole habitats. Link your pot D to eutrophication.
Write up your result
A sentence or two is enough to save it.
The lessons behind this practical
Each one opens with the same short film, and the film has a written transcript underneath if reading is easier than watching.
Now the quiz for this topic
Questions come from the lessons behind this practical, so nothing is asked that has not been taught.
Quiz
Living things and a changing environment quiz
4 questions from the lessons in this stage. No timer, and you can try again as many times as you like.