What does biodiversity describe within a community?
Variety of species
Biodiversity refers to the range and variety of different species present in a habitat or community.
A woodland contains 25 different species of plant. Which measure of biodiversity does this represent?
Species richness
Species richness counts how many different species are present, regardless of population size.
Why might two communities with the same species richness have different biodiversity values?
Differences in relative abundance.
Biodiversity also depends on how evenly individuals are distributed among species.
True or False:
A community with many species but dominated by one species will have a high diversity index.
False
If one species dominates numerically, the diversity index decreases because individuals are unevenly distributed.
What does the value N represent in the diversity index formula?
Total number of organisms
N is the total number of individuals across all species sampled in the community.
In the diversity index formula, what does n represent?
Number of individuals in a species
Each species has its own n value representing how many individuals belong to that species.
Fill in the blank:
The diversity index is calculated using the formula d = N(N−1) divided by ______.
Σn(n−1)
The denominator is the sum of n(n−1) calculated for each species in the sample.
What does a higher index of diversity value indicate about a community?
Greater biodiversity
Higher values indicate many species and a more even distribution of individuals.
True or False:
If all species in a community have similar population sizes, the diversity index tends to be higher.
True
Even distribution of individuals across species increases the diversity index.
Biodiversity can be measured at different scales. What term describes biodiversity measured across the whole planet?
Global biodiversity
Biodiversity can range from small local habitats to the entire Earth.
How do many intensive farming techniques typically affect biodiversity?
Reduce biodiversity
Monocultures, pesticide use, and habitat removal reduce species variety.
What key environmental decision must often be balanced when managing farmland biodiversity?
Conservation vs food production
Agricultural productivity must often be balanced with maintaining habitats and species diversity.
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3.1.1 Monomers & Polymers9
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3.1.2 Carbohydrates22
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3.1.3 Lipids17
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3.1.4 Proteins39
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3.1.5 Nucleic Acids32
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3.1.6 ATP11
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3.1.7 Water11
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3.1.8 Inorganic ions8
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3.2.1 Cell structure52
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3.2.2 Cell division20
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3.2.3 Transport across cell membranes20
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3.2.4 Cell recognition & the immune system36
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3.3.1 Surface area to volume ratio13
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3.3.2 Gas exchange24
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3.3.3 Digestion & absorption16
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3.3.4 Mass transport39
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3.4.1 DNA, genes & chromosomes13
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3.4.2 DNA & protein synthesis14
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3.4.3 Genetic diversity & meiosis14
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3.4.4 Genetic diversity & adaptation20
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3.4.5 Species & taxonomy20
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3.4.6 Biodiversity within a community12
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3.4.7 Investigating diversity12
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3.5.1 Photosynthesis23
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3.5.2 Respiration17
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3.5.3 Energy & ecosystems20
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3.5.4 Nutrient cycles15
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3.6.1 Stimuli & Response62
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3.6.2 Nervous coordination53
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3.6.3 Skeletal muscles14
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3.6.4 Homeostasis57
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3.7.1 Inheritance12
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3.7.2 Populations15
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3.7.3 Evolution may lead to speciation22
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3.7.4 Populations in ecosystems24
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3.8.1 Gene Mutations and Protein Structure14
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3.8.2 Control of Gene Expression44
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3.8.3 Applications of Genome Projects10
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3.8.4 Gene Technologies and Their Applications46
