Chapter 4: Environmental change and extinction
A species can survive many changes, but rapid habitat loss can outrun its capacity to adapt or move.
Part of your national curriculum
- Biology: genetics and evolution: 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
Lesson overview
What you'll learn in this lesson
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
Key learning points
- • Changing conditions
- • From decline to extinction
- • Evidence of risk
- • Conservation decisions
This lesson at a glance
- 30 minutes
- 15 parts to scroll through
- 3 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 15
Watch first
Chapter 4: Environmental change and extinction
An English teaching video on this topic from FuseSchool - Global Education. Watch it, then scroll down for the lesson.
In a nutshell
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
Learning cycle
Part 2 of 15
Learning cycle 1 of 2
Part 1 · Changing conditions
A short piece of teaching, then a check to make sure it has landed.
Explore the idea
Part 3 of 15
Learn
Changing conditions
Climate shifts, new predators, disease, competition, pollution and habitat destruction can change which traits are advantageous. The speed and scale of change matter.
Explore the idea
Part 4 of 15
Learn
From decline to extinction
If deaths repeatedly exceed births, a population shrinks. Small populations can lose genetic diversity and become vulnerable to chance events. Extinction occurs when the final member of a species dies.
Quick check
Part 5 of 15
Quick check
When is extinction complete?
Quick check
Part 6 of 15
Quick check
Why are small populations often vulnerable?
Reset break
Part 7 of 15
Pause
That's sitting 1 of 2 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 8 of 15
Learning cycle 2 of 2
Part 2 · Evidence of risk
A short piece of teaching, then a check to make sure it has landed.
Explore the idea
Part 9 of 15
Learn
Evidence of risk
Scientists combine population counts, breeding success, habitat measurements and long-term trends. A single low count may be noise; repeated decline across reliable surveys is stronger evidence.
Explore the idea
Part 10 of 15
Learn
Conservation decisions
Protecting habitats, reconnecting populations, reducing pollution and carefully managed breeding can reduce risk. Each action should target the known causes of decline and be monitored.
Quick check
Part 11 of 15
Quick check
Which is strongest evidence of decline?
Challenge round
Part 12 of 15
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
Challenge round
Part 13 of 15
Game · Fill the gaps
Finish the sentences
Choose the word that belongs in each gap.
Extinction occurs when the final member of a ____ dies.
Mastery quiz
Part 14 of 15
Marked quiz
End of lesson quiz: Chapter 4: Environmental change and extinction
3 questions, marked with the reasoning shown. No timer.
1. When is extinction complete?
2. Why are small populations often vulnerable?
3. Which is strongest evidence of decline?
Lesson round-up
Part 15 of 15
Lesson round-up
Ready when you are
Quiz score
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Luna: 0 out of 3 on the practice checks. Only if you feel up to it — one more?
Ask LunaDo the work
Your written work for this lesson
This is the part you'd do in your book at school. Pick the pieces below, write here or on paper, and photograph anything you draw or work out.
Why the school greenhouse failed
A science club grew tomato plants in the school greenhouse. In June the plants grew well: leaves were dark green and the fruit set quickly. In July the club went away for two weeks and left the greenhouse door shut. When they came back, the leaves were curled and pale and most of the fruit had dropped.
The club had a data logger inside. It showed the temperature reached 46 °C on several afternoons and the soil moisture fell close to zero. The club knew photosynthesis needs light, water and carbon dioxide, and that enzymes in a plant work best in a narrow range of temperature. Above that range the enzymes stop working properly.
The club repeated the summer with the door propped open and a water bottle drip on each pot. Temperature peaked at 31 °C and the plants survived.
Written for Good Learning Co.
Reading questions
- Name the variable the club changed the second time, and one variable they kept the same.
- Explain, using the words photosynthesis and enzymes, why the plants were damaged in July.
- Write a conclusion for the club's report, saying how far the evidence supports it.
Method and results
WritingWrite the aim, what you changed, what you measured and what you kept the same, then record your results in a table.
1 page + results table
Conclusion
WritingExplain what your results show and why, using the scientific words from the lesson. Say how you know you can trust them.
6–8 sentences
Labelled diagram
DiagramDraw the apparatus or the process in pencil, label it fully, and photograph it.
1 labelled diagram
Reading and notes
ReadingRead the lesson text again and write the key ideas in your own words.
Half a page of notes
Saved as you type.
Part 1 of 15 · Watch & discover
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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