Ecosystems, interdependence and human impact
Ecology studies how organisms depend on each other and their environment, and what happens when humans change the balance.
Lesson overview
What you'll learn in this lesson
Explain inheritance, variation, evolution and ecological relationships at GCSE standard.
Key learning points
- • Interdependence and adaptation
- • Sampling and quadrats
- • Cycles and human impact
This lesson at a glance
- 30 minutes
- 19 parts to scroll through
- 4 quick checks
- Marked quiz at the end
- Gentle pace: short sittings with pauses
Words to know
Scroll down — the lesson carries on below
Watch & discover
Part 1 of 19
Visual introductionPicture this
Ecosystems, interdependence and human impact
Ecology studies how organisms depend on each other and their environment, and what happens when humans change the balance.
In a nutshell
Explain inheritance, variation, evolution and ecological relationships at GCSE standard.
Learning cycle
Part 2 of 19
Learning cycle 1 of 2
Part 1 · Interdependence and adaptation
A short piece of teaching, then a check to make sure it has landed.
Explore the idea
Part 3 of 19
Learn
Interdependence and adaptation
Organisms compete for resources: animals for food, mates and territory; plants for light, water, space and mineral ions. Adaptations may be structural, behavioural or functional, and extremophiles survive conditions such as high temperature or salinity that would kill most organisms.
Reset break
Part 4 of 19
Pause
That's sitting 1 of 5 done
Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.
Explore the idea
Part 5 of 19
Learn
Sampling and quadrats
A quadrat placed using random coordinates estimates population size in a uniform area, and mean per quadrat multiplied by total area estimates the population. A transect measures how distribution changes along an environmental gradient, such as from a path into woodland. More samples improve reliability.
Quick check
Part 6 of 19
Quick check
Part 7 of 19
Reset break
Part 8 of 19
Pause
That's sitting 2 of 5 done
Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.
Learning cycle
Part 9 of 19
Learning cycle 2 of 2
Part 2 · Cycles and human impact
A short piece of teaching, then a check to make sure it has landed.
Explore the idea
Part 10 of 19
Learn
Cycles and human impact
Carbon and water cycle continuously, with decomposers returning nutrients to the soil. Human activity reduces biodiversity through deforestation, peat destruction, pollution and land use for building and farming. Greenhouse gas emissions drive global warming, and conservation programmes, breeding schemes and habitat protection aim to reverse the losses.
Quick check
Part 11 of 19
Reset break
Part 12 of 19
Pause
That's sitting 3 of 5 done
Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.
Quick check
Part 13 of 19
Explore the idea
Part 14 of 19
Worked example
Worked answer: describe how to estimate the number of daisies in a field using quadrats (4 marks)
Use random number pairs as coordinates to place a 1 m² quadrat, avoiding bias in where it lands (1). Count the daisies inside each quadrat and repeat for at least ten quadrats (1). Calculate the mean number per quadrat (1). Multiply the mean by the total area of the field in square metres to estimate the population; more quadrats make the estimate more reliable (1).
Challenge round
Part 15 of 19
Game · Sort it
Which of these are true?
Drag each card into the right column. Tap a card first if dragging is fiddly.
True
Not true
Reset break
Part 16 of 19
Pause
That's sitting 4 of 5 done
Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.
Challenge round
Part 17 of 19
Game · Recall cards
Quadrats must be placed randomly to
Card 1 of 4
Mastery quiz
Part 18 of 19
Marked quiz
End of lesson quiz: Ecosystems, interdependence and human impact
4 questions, marked with the reasoning shown. No timer.
1. Quadrats must be placed randomly to
2. A transect is used to measure
3. Decomposers are important because they
4. Deforestation reduces biodiversity mainly by
Lesson round-up
Part 19 of 19
Lesson round-up
Ready when you are
Quiz score
Not sat
Games
Not played
Points this lesson
0
Best run
0 in a row
Luna: 0 out of 4 on the practice checks. Only if you feel up to it — one more?
Ask LunaPart 1 of 19 · Watch & discover