Biology 9700 · AS & A Level · Conservation

Conservation — practice question

(a)[3]

List three reasons that make it important to conserve endangered plant species.

(b)

The tree $\textit{Vatica guangxiensis}$ is an endangered species. There are only three wild populations, and all of them are in south-western China. Conservation work for this species started in the 1980s. The conservation approaches used included efforts to protect the habitat of the wild populations and the creation of a fourth population at the Xishuangbanna Tropical Botanical Garden. In 2002, the genetic diversity of all four populations was measured. This involved analysing DNA samples from several individuals. • Twenty different regions of DNA were examined using electrophoresis. • For each population, the proportion of samples showing differences in DNA structure, seen as different bands on the DNA ‘fingerprint’, was calculated. • This value was written down as the percentage of polymorphic bands. A greater percentage of polymorphic bands indicates greater genetic diversity within the population. Table 4.1 presents the results.

(b(i))[2]

Using Table 4.1, compare the genetic diversity of $\textit{V. guangxiensis}$ in the botanic garden with that in the wild populations.

(b(ii))[2]

Suggest reasons for the comparatively low percentage of polymorphic bands measured in wild population C.

(b(iii))[2]

Explain why it matters for a species to have high genetic diversity.

(a(i))[2]

Using Table 4.1, compare the genetic diversity of \textit{V. guangxiensis} in the botanic garden with that in the wild populations.

(a(ii))[2]

Suggest reasons for the comparatively low percentage of polymorphic bands measured in wild population C.

(a(iii))[2]

Explain why high genetic diversity matters for a species.

(a(iv))[2]

The Xishuangbanna Tropical Botanical Garden is only tens of kilometres from the habitats of the wild populations of $\textit{V. guangxiensis}$. Suggest how this may aid the long-term conservation of this species.

(c(i))[2]

Explain why storing seeds may conserve the species more successfully than maintaining a population of growing plants.

(c(ii))[2]

Suggest why a sample of each seed type kept in a seed bank is germinated every few years.

Worked solution & mark scheme

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