A-LevelBiologyBiodiversity and conservation9700/42 · Feb/Mar 2025 · Q713 Marks

The Sumatran tiger, Panthera tigris sumatrae, is classified as critically endangered on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species™™. [Figure 7.1] shows a Sumatran tiger. (a) Fig. 7.2 shows the number of wild Sumatran tigers in the world between 1970 and 2020. [Figure 7.2] (c) Captive breeding programmes sometimes use IVF. Table 7.1 shows some of the events that occur during an IVF procedure. They are not listed in the correct order. Table 7.1 letter event A sperm added to oocyte B embryo formed C female given hormones to stimulate ovulation D zygote placed in culture medium E embryo placed in uterus of female F zygote formed G oocyte harvested with a fine needle Complete Table 7.2 to show the correct order of the events. One of the events has already been added in the correct position. Table 7.2 correct order letter 1 2 3 4 F 5 6 7

(a)(i)Calculate the mean rate of decrease in the Sumatran tiger population between 1970 and 2020. mean rate of decrease =[2]
(a)(ii)There are a number of different ways to help conserve Sumatran tigers. For example, some zoos have captive breeding programmes. Outline ways in which Sumatran tigers may be conserved, other than captive breeding programmes.[3]
(b)Outline reasons for maintaining animal biodiversity.[4]
(c)Complete Table 7.2 to show the correct order of the events. One of the events has already been added in the correct position.[4]

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Mark scheme

Marking points from the official mark scheme (Feb/Mar 2025). The mark or mark type is shown in brackets.

[2] 10.8 (year-1);; if value for rate is incorrect allow 1 mark for: 1010-470 or 50 540 50
[3] any three from: 1 ban, hunting / poaching / trade ; 2 enforcement / strict penalties ; 3 national parks / protected reserves / habitat protection / AW ; 4 tracking devices / monitoring; 5 raise awareness / education; 6 AVP; e.g. veterinary care
[4] any four from: 1 maintain, gene pool/genetic diversity ; 2 ecotourism; 3 ethical / moral, reasons; 4 reference to effect on, ecosystems / food chains / food webs; 5 aesthetic reasons; 6 idea of research; 7 cultural significance ; 8 pollination; 9 AVP; e.g. keystone species
[4] correct order 1 C 2 G 3 A 4 F 5 D 6 B 7 E CGA in correct order ; ignore intervening letters CGA above F; DBE in correct order ;ignore intervening letters DBE below F;

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