Biodiversity

Biodiversity is topic 8.6 of AP Biology, inside Ecology. This page works through three real practice questions on it, with the full reasoning behind each credited answer.

Practise this topic freeThe whole unit
21 questionsRepresenting and Describing Data90% with a figure
Worked examples

Three real biodiversity questions

From the practice pool, not the mock papers — each with the reasoning that produces the answer.

90% of them come with a figure. Reading the graph or diagram correctly is most of the work here before any content knowledge applies.

Representing and Describing Data · with figure

A grassland fire removes aboveground vegetation but leaves soil intact. Plant cover is measured during recovery. Which interpretation is best supported?

  1. ACommunity recovery after disturbance with soil remaining is secondary successioncorrect
  2. BThe data show that plant cover becomes genetically identical at all times.
  3. CPrimary succession is occurring because no soil remains after the fire.
  4. DSuccession cannot occur after a disturbance.
Why A is correct

Because the fire disturbs the community but leaves soil intact, the changing plant community over time is consistent with secondary succession.

The evidence in the prompt matters before the topic label: "A grassland fire removes aboveground vegetation but leaves soil intact. Plant cover is measured during recovery....". The supported answer is "Secondary succession is occurring because the community changes over time..." because Because the fire disturbs the community but leaves soil intact, the changing plant community over time is consistent with secondary succession. Distractors such as data show that plant cover becomes genetically identical at all times or Primary succession is occurring because no soil remains after the fire either ignore the stated pattern or name a related concept without matching the evidence.

Representing and Describing Data · with figure

A field study compares crop plots with different pollinator access. Which interpretation is best supported? Use Figure 1 to answer the question.

  1. AThey convert fruit into soil minerals
  2. BPollinator visits decrease fruit set because open plots have lower fruit set.
  3. CThe exclusion net increases fruit set by preventing all flower development.
  4. DMore visits are associated with higher fruit setcorrect
Why D is correct

Open plots have many more pollinator visits and higher fruit set than pollinator-exclusion plots. The data support an association between pollinator access and crop fruit set.

The evidence in the prompt matters before the topic label: "A field study compares crop plots with different pollinator access. Which interpretation is best supported". The supported answer is "Greater pollinator access is associated with higher fruit set in these plots" because Open plots have many more pollinator visits and higher fruit set than pollinator-exclusion plots. Distractors such as Pollinators are decomposers because they convert fruit into soil... or Pollinator visits decrease fruit set because open plots have lower... either ignore the stated pattern or name a related concept without matching the evidence.

Statistical Tests and Data Analysis · with figure

Two forest plots are surveyed. Species richness is the number of species present. Which plot has greater richness, and by how many species?

  1. ARichness is species count, so 6 minus 4 equals 2correct
  2. BRepeated shared species are counted twice
  3. CPlot B by 10 species, because 6 plus 4 equals 10.
  4. DThe plots have equal richness because they share four species.
Why A is correct

Plot A has 4 species, and Plot B has 6 species. Plot B therefore has greater species richness by 2 species.

The stem asks for a numerical or quantitative judgment: "Two forest plots are surveyed. Species richness is the number of species present. Which plot has greater richness,...". The safe route is to identify the counted event, use the full denominator, and then interpret the number biologically. Here the worked reasoning is Plot A has 4 species, and Plot B has 6 species, so choices based on Plot A by 2 species, because repeated shared species are counted twice or Plot B by 10 species, because 6 plus 4 equals 10 lose the required setup.

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Last reviewed 2026-08-28. Topic and unit names follow the College Board course framework. Question counts describe the PrepScore practice bank, not the exam.
Same unit
Population Ecology39 questionsCommunity Ecology33 questionsEnergy Flow Through Ecosystems24 questions

Work biodiversity until the reasoning is automatic.

Real AP questions with a full explanation on every answer, and a mistake bank that only clears when you get it right.

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