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:
- biodiversity — includes → genetic diversity
- biodiversity — includes → species diversity
- biodiversity — includes → ecosystem diversity
- genetic diversity — increases → resilience
- ecosystem diversity — supports greater → species diversity
Award 1 mark per correctly labelled arrow with a valid linking phrase. Maximum 5 marks.