Biology • Year 11 • Module 3 • Lesson 3
What is Biodiversity?
Lock in the core vocabulary, the three levels of biodiversity, and the key ideas about species richness, evenness, and Australia as a megadiverse country.
1. Complete the paragraph
Fill each blank with the correct term from the word bank. Use each term once only. 8 marks
_______________ is the variety of all living organisms in an ecosystem, and it operates at three distinct levels. _______________ refers to variation in alleles within a species or population. _______________ considers how many species are present in an area and how evenly individuals are distributed. Specifically, _______________ counts the number of different species, while _______________ measures how equally individuals are spread across those species. _______________ refers to the variety of habitats, communities and ecological processes in a region. Australia is described as a _______________ country because it contains an exceptionally high proportion of _______________species found only in Australia and nowhere else on Earth.
2. Term–definition match
Write the matching term from this list in the right-hand column: biodiversity • genetic diversity • species richness • species evenness • ecosystem diversity • endemic species • resilience • alleles. 8 marks
| # | Definition | Matching term |
|---|---|---|
| 2.1 | The variety of all living organisms in an ecosystem, operating at genetic, species and ecosystem levels. | |
| 2.2 | Variation in alleles within a species or population. | |
| 2.3 | The number of different species in a given area. | |
| 2.4 | How equally individuals are distributed across species in a community. | |
| 2.5 | The variety of habitats, communities and ecological processes in a region. | |
| 2.6 | A species found only in one specific geographic location. | |
| 2.7 | The ability of a system to recover after disturbance. | |
| 2.8 | Alternative forms of the same gene found in a population. |
3. Classify biodiversity examples
For each example below, write G (genetic), S (species diversity) or E (ecosystem diversity) in the Type column. 8 marks
| Type (G/S/E) | Example |
|---|---|
| A koala population contains several alleles linked to immune response | |
| A woodland supports 42 bird species with relatively balanced numbers | |
| A region includes rainforest, estuary, mangrove and seagrass habitats | |
| A coral reef has many fish species, but one species makes up 80% of individuals | |
| Variation in shell-colour alleles within one snail population | |
| A reserve containing both arid grassland and wetland communities | |
| A botanical garden contains 120 different plant species from around the world | |
| Within a single eucalyptus species, different populations carry different disease-resistance gene variants |
4. True or false, with correction
Circle T or F. If the statement is false, write the corrected version on the line below. 8 marks, 1 for T/F, 1 for correction where needed
4.1 Biodiversity only refers to the number of different species in a given area. T / F
4.2 A habitat with 15 species where one species makes up 90% of all individuals has lower species diversity than a habitat where 10 species are distributed more evenly. T / F
4.3 Australia is considered megadiverse mainly because it is one of the largest countries on Earth. T / F
4.4 Higher genetic diversity within a population generally increases its chance of surviving environmental change. T / F
5. Build a concept map
Draw labelled arrows between the five terms below to show how they connect. Each arrow must carry a linking phrase. Aim for at least 5 labelled arrows. 5 marks
Supplied terms: biodiversity • genetic diversity • species diversity • ecosystem diversity • resilience.
Q1, Cloze paragraph
In order: Biodiversity • genetic diversity • species diversity • species richness • species evenness • ecosystem diversity • megadiverse • endemic species.
Q2, Term–definition matches
2.1 biodiversity • 2.2 genetic diversity • 2.3 species richness • 2.4 species evenness • 2.5 ecosystem diversity • 2.6 endemic species • 2.7 resilience • 2.8 alleles.
Q3, Classification answers
G Koala immune alleles • S 42 bird species balanced • E Rainforest/estuary/mangrove/seagrass region • S Coral reef with 80% one species (high richness, low evenness) • G Snail shell-colour alleles • E Arid grassland + wetland • S 120 plant species • G Disease-resistance gene variants within one eucalyptus species.
Q4, True/False with correction
4.1 False. Correction: Biodiversity operates at three levels, genetic diversity, species diversity (including richness and evenness) and ecosystem diversity. Counting only species number is incomplete.
4.2 True. High richness can coexist with low evenness; species diversity considers both richness and evenness, so a more evenly distributed community can have higher species diversity even with fewer species.
4.3 False. Correction: Australia is considered megadiverse because of its exceptional biodiversity, high proportion of endemic species, and long evolutionary isolation, not simply because of its land area.
4.4 True.
Q5, Sample concept map
Accept any biologically valid linking phrases. A correct map should include arrows such as:
- biodiversityincludes → genetic diversity
- biodiversityincludes → species diversity
- biodiversityincludes → ecosystem diversity
- genetic diversityincreases → resilience
- ecosystem diversitysupports greater → species diversity
Award 1 mark per correctly labelled arrow with a valid linking phrase. Maximum 5 marks.