Biodiversity and its measurementEdexcel A-Level Biology A: Mind map

Exam questions on Biodiversity and its measurement

1. A botanist surveys the forest on a remote island. She records 42 plant species in total. Nine of these grow naturally on the island and nowhere else in the world; the other 33 also occur on the nearby mainland.
   Suggest why endemic species are more at risk of extinction from human activity than species that also occur elsewhere.2 marks
2. A conservation geneticist studies one gene locus in two populations of a rare orchid. In population A, 35 of the 50 plants sampled are heterozygous at the locus. In population B, 6 of the 40 plants sampled are heterozygous at the locus.
   Calculate the heterozygosity index for population B and state which population has the greater genetic diversity at this locus.2 marks
3. A student compares the beetles living in two habitats using pitfall traps. In the meadow she catches 50 beetles belonging to 5 species, in numbers of 20, 15, 10, 4 and 1. In the hedge bank she catches 50 beetles belonging to 3 species, in numbers of 40, 8 and 2. She uses the index of diversity, D = N(N − 1) / Σn(n − 1), where N is the total number of individuals and n is the number of individuals of each species.
   Calculate the index of diversity for the meadow. Show your working.3 marks