The shape of the lesson
By the end of the lesson, learners can
- Sustainable resources: fish and forests: Set the fishing effort, choose any conservation measures and press Fish for 30 years.
- Endangered species and how to save them: The conservation tab starts with a healthy wild population of 40 animals; the colours stand for different alleles.
- Why conserve, and genetic variation: Extended.
- Sustainable: produced as rapidly as it is removed, so it does not run out.
- Fish (Extended): education, closed seasons, protected areas, net types and mesh size, quotas, monitoring.
- Forests (Extended): education, protected areas, quotas, replanting.
- Small populations (Extended): low genetic variation; AI and IVF bring in new alleles.
One picture every idea returns to
A sustainable resource is one which is produced as rapidly as it is removed from the environment, so that it does not run out. Forests and fish stocks can be conserved and managed sustainably. Organisms become endangered or extinct through climate change, habitat destruction, hunting, overharvesting, pollution and introduced species. They can be conserved by monitoring and protecting species and habitats, education, captive breeding programmes and seed banks.
Forty-five minutes, phase by phase
| Time | Phase | What happens in the room | Grouping |
|---|---|---|---|
| 0 to 5 min | Hook: predict | Open with the question in the title, Take only what grows back.. A forest or a fishery can supply people for ever, as long as no more is taken each year than grows back. Put the figure on the board: it is the one picture every idea in the lesson returns to. | Whole class, then pairs |
| 5 to 13 min | Teach and check: Sustainable resources: fish and forests | Set the fishing effort, choose any conservation measures and press Fish for 30 years. Project tab 6 of the lab (Managing a fishery sustainably) and let a student drive it while the class predicts. | Whole class, then pairs |
| 13 to 21 min | Teach and check: Endangered species and how to save them | The conservation tab starts with a healthy wild population of 40 animals; the colours stand for different alleles. Project tab 7 of the lab (Endangered species, captive breeding and genetic variation) and let a student drive it while the class predicts. | Pairs |
| 21 to 30 min | Teach and check: Why conserve, and genetic variation | Extended. | Cooperative Concept Mapping |
| 30 to 36 min | Check | The four Stage 1 questions from the student lesson, answered on mini whiteboards or by show of fingers. Re-teach the one most get wrong. | Individual, then whole class |
| 36 to 43 min | Plenary | The exam-style questions from Stage 2, one at a time: thirty seconds alone, then a random call. The feedback lines in the key give the examiner's wording. | Individual, random call |
| 43 to 45 min | Exit and homework | Set the worksheet below (6 questions, 24 marks). Learners self-assess against the objectives before they leave. | Individual |
Protect the parts that carry the learning
The sequence carries about fifty minutes of material, so the lab is driven by one student while the class predicts rather than explored freely. Times are a guide.
Protected: the check at 30 minutes. It is the only individual read on whether the key idea landed, and it is not cut.
Cut first if the build overruns: the last check in Why conserve, and genetic variation, never the check or the plenary.
In a 60 minute block: run worksheet questions 1 to 3 in class as a Rally Coach set and model both the hardest worked example and its check live.
Cooperative Concept Mapping
Teams receive the key terms on cards and arrange them on a large sheet, drawing and labelling the links. Compare maps between teams before showing the model map.
The full structure, with its variations and the other twelve, is on the cooperative-learning page.
What to head off, and how
| Trap learners fall into | Teaching move that pre-empts it |
|---|---|
| A larger mesh size lets young, small fish escape, so they survive to reproduce. | It does not mean catching bigger fish to make more money. |
| Increasing the number of animals does not restore genetic variation on its own. | New alleles must come from unrelated animals, for example by AI or IVF with animals from other populations. |
Conservation: worksheet
6 questions, 24 marks. Written in the style of the papers; no past paper question is reproduced.
Give four reasons why organisms become endangered or extinct.
Describe how endangered species can be conserved.
The table shows the estimated mass of adult cod in a sea area.
| Year | 1970 | 1980 | 1990 | 2000 | 2010 | 2020 |
|---|---|---|---|---|---|---|
| Mass of adult cod / thousand tonnes | 250 | 160 | 90 | 60 | 95 | 140 |
Quotas and a larger mesh size were introduced in 2000. (a) Calculate the percentage decrease from 1970 to 2000. (b) Describe and explain the change after 2000.
Extended. Explain how forests can be conserved.
Extended. A zoo has a small group of an endangered antelope. Explain the risks to the species of the small population size, and how AI and IVF can be used in a captive breeding programme.
Extended. Describe the reasons for conservation programmes.
Answer key and marking notes
- Habitat destruction (for example deforestation).
- Hunting or overharvesting.
- Pollution, or climate change.
- Introduced species that prey on or compete with them. (Any four of: climate change, habitat destruction, hunting, overharvesting, pollution, introduced species.)
- Monitoring population numbers and protecting the species and its habitat, for example in reserves, with laws against hunting.
- Education, so people understand why the species matters and do not harm it.
- Captive breeding programmes in zoos, then releasing animals into protected habitats.
- Seed banks that store seeds of endangered plants so they can be grown again.
- (a) (250 − 60) ÷ 250 × 100 = 76%.
- (b) After 2000 the stock rose from 60 to 140 thousand tonnes.
- Quotas limited the number of fish removed each year.
- A larger mesh let young fish escape, grow and breed, so fish were replaced faster than they were removed.
- Education about the importance of forests and sustainable timber, so people buy from managed forests.
- Protected areas such as national parks or reserves where felling is not allowed.
- Quotas that limit the number of trees that can be felled.
- Replanting, so new trees replace those cut down and the forest is produced as fast as it is removed.
- A small population carries few different alleles, so genetic variation is reduced.
- The species is less able to adapt to environmental change and one disease could kill them all; inbreeding increases harmful recessive conditions.
- AI: sperm from a male in another zoo or the wild is placed in a female, so new alleles are introduced without moving animals.
- IVF: eggs are fertilised with sperm outside the body and the embryos implanted into a female (perhaps a surrogate), increasing numbers and genetic variation.
- To maintain or increase biodiversity.
- To reduce extinction of species.
- To protect vulnerable ecosystems.
- To maintain ecosystem functions such as nutrient cycling and resource provision: food, drugs, fuel and genes.
8 multiple-choice questions on this lesson
From the topic question bank. Assign them in the app for a marked score in your gradebook, or run the topic as a class game.
Which describes a sustainable resource?
- AOne produced as rapidly as it is removed, so it does not run out
- BOne that is never taken from the environment by humans
- COne that can be removed at any rate because it is renewable
- DOne that is replaced only after it has been used up
Which is the main purpose of a seed bank?
- AStoring seeds of endangered plants so the species can be grown again
- BSelling seeds of high-yielding crops to farmers each year
- CTesting seeds to find which grow fastest in warm soil
- DProducing new plant species by mixing different seeds
Rats arrive on an island on ships and eat the eggs of a ground-nesting bird. The bird becomes endangered. What is the cause?
- AAn introduced species
- BOverharvesting
- CHabitat destruction
- DClimate change
Rangers fit radio collars to tigers in a reserve and count them each year. Which conservation method is this?
- AMonitoring and protecting a species
- BA captive breeding programme
- CA seed bank
- DA fishing quota
A fish stock of 200 000 tonnes grows by 30 000 tonnes each year by reproduction and growth. Which annual catch is sustainable?
- A25 000 tonnes
- B45 000 tonnes
- C60 000 tonnes
- D200 000 tonnes
A government bans fishing for cod in one area from January to April, when the cod spawn. Which conservation measure is this?
- AA closed season
- BA protected area
- CA quota
- DA mesh size control
A zoo has five related female pandas. Which method would best increase genetic variation in their offspring?
- AArtificial insemination with sperm from an unrelated male in another country
- BBreeding the females with their own brothers in the same zoo
- CMoving the pandas to a larger enclosure with more food
- DKeeping only the healthiest female to breed each year
Mangrove forests protect coasts from storms, provide nursery areas for fish and are a source of timber and medicines. Which reason for conservation does this mainly illustrate?
- AMaintaining ecosystem functions such as resource provision
- BIncreasing the number of introduced species
- CReducing genetic variation in mangrove trees
- DReplacing natural forest with plantations
Quiz key
A sustainable resource is produced as rapidly as it is removed from the environment, so it does not run out. Resources such as fish and timber are used, so it is not about never taking them; being renewable does not mean any rate of removal is safe; waiting until it is used up is not sustainable.
Seed banks store dried, cold seeds of many plants, including endangered ones, so they can be grown and reintroduced if the species declines. They are not shops, growth-testing labs or a way to create new species.
A species brought to a new area by humans is an introduced species; here it preys on the birds' eggs. Overharvesting means people taking too many of the bird; habitat destruction and climate change change the environment rather than adding a predator.
Tracking and counting animals in their habitat is monitoring, which goes with protecting them. Captive breeding takes animals into zoos; seed banks store plant seeds; quotas limit how many fish are caught.
A catch of 25 000 tonnes is less than the 30 000 tonnes added each year, so the stock stays the same or grows. 45 000 and 60 000 tonnes remove more than is replaced, so the stock falls each year; 200 000 tonnes takes the whole stock.
A closed season stops fishing during part of the year, here the breeding season, so fish can reproduce. A protected area bans fishing in a place all year; a quota limits the total catch; mesh size controls which fish escape the nets.
AI with sperm from an unrelated male brings new alleles into the captive group without moving animals, increasing genetic variation. Breeding with brothers is inbreeding and lowers variation; more space and food help health but add no alleles; breeding from one female reduces variation further.
Fish, timber and medicines are resources provided by the ecosystem, so conserving mangroves maintains ecosystem functions such as resource provision. Introducing species and reducing genetic variation are threats, not reasons for conservation, and replacing forest with plantations would remove those functions.
What to project
The student lesson embeds these tabs. Open them full screen on the projector; every slider has a drag handle on the stage.
Slides for this lesson
A projectable deck for every pack is on the way. Until then, present the student lesson full screen: its sections, figure and lab tabs follow the same order as the plan above.