Biodiversity Basics
This term describes the variety of living organisms and ecosystems on Earth.
What is biodiversity?
The definition of a clade is?
What is a group of organisms that includes a common ancestor and all its descendants?
This term describes the role and position of an organism in its environment, including interactions and feeding.
What is an ecological niche?
The maximum population size an environment can sustainably support.
What is carrying capacity?
The gradual process of change in species composition in an ecosystem.
What is ecological succession?
This index combines species richness and evenness to provide a single measure of biodiversity.
What is Simpson’s Diversity Index?
The three common assumptions of cladistics are?
What is common ancestry, bifurcation and physical change?
The principle stating that two species with identical niches cannot coexist indefinitely.
What is the competitive exclusion principle?
This type of growth curve represents unrestricted population growth.
What is exponential growth/J-curve?
Refer to the graph provided by your teacher and identify the type of succession that occurred and give a reason
Primary succession - starts with high numbers of pioneer species and as it reaches climax community there are more long-lived plants
Climate, soil type, and area size are examples of these factors that influence biodiversity
What are abiotic factors?
Biological classification is hierarchical and based on levels of similarity of what three things?
What is physical features, methods of reproduction and molecular sequences?
Only about 10% of energy is passed from one trophic level to the next. The other 90% is lost mostly as this.
What is heat (respiration/loss of energy)?
One evening 55 green tree frogs were captured, marked and released. The following evening 70 frogs were captured in the same area, of which 35 were marked. Infer a green frog population in the area.
Size of population (N) = M x n
= 55 x 70
35
= 110
ability to fixate nitrogen,
tolerance to extreme conditions,
rapid germination of seeds,
ability to photosynthesise
A rainforest ecosystem has 5 species of trees. Species A makes up 80% of the population, while the other 4 species share the remaining 20%. Compared to a forest where all 5 species occur in equal numbers, which measure of diversity would be lower in the rainforest?
What is species evenness?
Use the Specht's structural forms of vegetation classification system. (hard copy from teacher)
Classify the community the ecologist recorded as Main vegetation Eucalyptus trees 10-20 metres in height; average tree canopy cover 75%
Closed forest
Refer to the Australian food web from your teacher.
What is the keystone species?
Short-beaked echidna
On the whiteboard, draw a graph that would represent a population of possums colonising a newly regenerated forrest and justify your choice
teacher discretion
Refer to the data your teacher will provide.
Predict which human impact will have the highest and lowest impacts on biodiversity in 2023, justify your answer.
Highest: Habitat destruction - 2026 high quality, high level of consensus evidence that habitat destruction was causing adverse effects and impact was deteriorating. This is in contrast to 2011 when impact was improving.
Lowest: Overexploitation - in 2016 there was adequate high quality evidence to suggest that over exploitation was impacting a small proportion of species/ecosystems, this was improving from 2011 where high quality evidence indicated a large proportion of species was being affected which means that measure to improve exploitation have been implemented since 2011
A study measures diversity in two wetlands across 10 years. Wetland A shows consistent richness but decreasing evenness, while Wetland B shows stable evenness but declining richness. Which wetland has experienced a greater reduction in biodiversity overall, and why?
What is Wetland B, because the loss of richness (species extinction) reduces biodiversity more fundamentally than shifts in abundance?
the process of stratified sampling can be described in terms of? (hint - 4 steps)
- purpose
- site selection
- minimising bias
- methods of data presentation and analysis
Teacher discretion
A population of wallabies in a national park starts with 1,200 individuals.
Over the course of one year:
Births: 300
Deaths: 150
Immigration: 50
Emigration: 100
Calculate the population change.
Calculate the population growth rate (as a percentage of the original population).
Population change = (Births + Immigration) – (Deaths + Emigration)
= (300 + 50) – (150 + 100)
= +100 individuals
Growth rate = (Change ÷ Original Population) × 100
= (100 ÷ 1200) × 100
= 8.3% increase
On the whiteboard draw an example of the successional changes that could occur on a volcanic island. To get full marks appropriate terminology must be used in labelling your diagram
teacher discretion
Primary succession
Pioneer species
Soil development (from weathering and organic matter accumulation)
Intermediate community (grasses, shrubs, small trees)
Climax community