lOMoARcPSD| 54339004
IB ESS TOPIC 3 - BIODIVERSITY AND
CONSERVATION QUESTIONS AND ANSWERS
WITH VERIFIED SOLUTIONS 100% CORRECT
RATED A+ NEWLY UPDATED 2025
Environmental Pressures
✔✔ Abiotic or biotic factors in an ecosystem that challenge an organism's survival and increase
competition (intra- or inter-species).
Biodiversity
✔✔ The variety of life in an ecosystem, including species diversity, genetic diversity, and
habitat diversity.
Variation
✔✔ Differences—either genetic or physical—between individuals within a species.
Simpson’s Diversity Index
✔✔ A mathematical measure of biodiversity that accounts for species richness and evenness in
an ecosystem.
Species Diversity
✔✔ The number of species (richness) and their relative abundance (evenness) in a community.
Genetic Diversity
✔✔ The total variety of genetic information within a population or species.
Random Genetic Mutations
✔✔ Small, random changes in genetic material that occur during reproduction; can lead to
variation within a species.
Hotspots
✔✔ Areas with exceptionally high biodiversity that are under threat from human activities.
Endemic Species
✔✔ Species found only in one specific geographic area and nowhere else.
Speciation
✔✔ The formation of new species from existing populations, usually due to geographic
isolation over time.
, lOMoARcPSD| 54339004
Evolution
✔✔ The gradual process by which species adapt to environmental pressures over generations
through natural selection.
Natural Selection
✔✔ Process where individuals with advantageous traits survive and reproduce more
successfully, passing those traits on.
Geographical Isolation
✔✔ When populations of the same species are separated physically, preventing interbreeding
and possibly leading to speciation.
Physical Barriers
✔✔ Natural features such as mountains, rivers, or oceans that prevent species from
interbreeding.
Land Bridges
✔✔ Natural connections between land masses (e.g. due to lower sea levels), allowing species
migration.
Continental Drift
✔✔ The slow movement (about 1 cm/year) of Earth’s tectonic plates, altering the positions of
continents over millions of years.
Lithosphere
✔✔ The solid, rocky outer layer of Earth, including the crust and upper mantle.
Gondwana
✔✔ An ancient supercontinent made up of what is now Africa, South America, India,
Australia, New Zealand, Arabia, and Antarctica.
background extinction rate - ANSWER✔✔the natural rate of extinction of species - around 1
species per million species per year
extinction - ANSWER✔✔the complete loss of a species from Earth - no more individuals of
that species exist
mass extinctions - ANSWER✔✔an extinction rate far greater than background extinction rate
Holocene extinction event - ANSWER✔✔the 6th mass extinction occurring for the last 10,000
years, however, much faster in the last 100 years - generally agreed to be as a result of human
activity
IB ESS TOPIC 3 - BIODIVERSITY AND
CONSERVATION QUESTIONS AND ANSWERS
WITH VERIFIED SOLUTIONS 100% CORRECT
RATED A+ NEWLY UPDATED 2025
Environmental Pressures
✔✔ Abiotic or biotic factors in an ecosystem that challenge an organism's survival and increase
competition (intra- or inter-species).
Biodiversity
✔✔ The variety of life in an ecosystem, including species diversity, genetic diversity, and
habitat diversity.
Variation
✔✔ Differences—either genetic or physical—between individuals within a species.
Simpson’s Diversity Index
✔✔ A mathematical measure of biodiversity that accounts for species richness and evenness in
an ecosystem.
Species Diversity
✔✔ The number of species (richness) and their relative abundance (evenness) in a community.
Genetic Diversity
✔✔ The total variety of genetic information within a population or species.
Random Genetic Mutations
✔✔ Small, random changes in genetic material that occur during reproduction; can lead to
variation within a species.
Hotspots
✔✔ Areas with exceptionally high biodiversity that are under threat from human activities.
Endemic Species
✔✔ Species found only in one specific geographic area and nowhere else.
Speciation
✔✔ The formation of new species from existing populations, usually due to geographic
isolation over time.
, lOMoARcPSD| 54339004
Evolution
✔✔ The gradual process by which species adapt to environmental pressures over generations
through natural selection.
Natural Selection
✔✔ Process where individuals with advantageous traits survive and reproduce more
successfully, passing those traits on.
Geographical Isolation
✔✔ When populations of the same species are separated physically, preventing interbreeding
and possibly leading to speciation.
Physical Barriers
✔✔ Natural features such as mountains, rivers, or oceans that prevent species from
interbreeding.
Land Bridges
✔✔ Natural connections between land masses (e.g. due to lower sea levels), allowing species
migration.
Continental Drift
✔✔ The slow movement (about 1 cm/year) of Earth’s tectonic plates, altering the positions of
continents over millions of years.
Lithosphere
✔✔ The solid, rocky outer layer of Earth, including the crust and upper mantle.
Gondwana
✔✔ An ancient supercontinent made up of what is now Africa, South America, India,
Australia, New Zealand, Arabia, and Antarctica.
background extinction rate - ANSWER✔✔the natural rate of extinction of species - around 1
species per million species per year
extinction - ANSWER✔✔the complete loss of a species from Earth - no more individuals of
that species exist
mass extinctions - ANSWER✔✔an extinction rate far greater than background extinction rate
Holocene extinction event - ANSWER✔✔the 6th mass extinction occurring for the last 10,000
years, however, much faster in the last 100 years - generally agreed to be as a result of human
activity
