Biodiversity and its measurementEdexcel International A Level Biology: Mind map

Exam questions on Biodiversity and its measurement

1. A conservation team surveyed a cloud forest on a tropical mountain. Many of the species they recorded, including a tree frog and an orchid, are found nowhere else in the world.
   Explain why endemic species are particularly vulnerable to extinction when their habitat is destroyed.2 marks
2. Researchers studied one gene with two alleles in lizards. On a small island, a population of 60 lizards contained 15 heterozygotes. On the mainland, a population of 200 lizards of the same species contained 82 heterozygotes.
   Suggest two reasons why the island population has a lower heterozygosity index than the mainland population.2 marks
3. Students estimated the biodiversity of two meadows, A and B, by counting the individuals of each plant species in random quadrats. Meadow A contained 5 species, with 20, 15, 10, 4 and 1 individuals. Meadow B contained 4 species, with 38, 8, 3 and 1 individuals. Meadow B had been treated with a herbicide the previous year, but meadow A had not. The index of diversity is D = N(N − 1) / Σn(n − 1), where N is the total number of individuals of all species and n is the number of individuals of each species.
   Calculate the index of diversity D for meadow A. Show your working.3 marks