Page 09 13. Inbreeding depression is a result of A an increase in heterozygotes B a genetically variable population C crossbreeding for improved characteristics D an accumulation of recessive deleterious alleles. 14. Livestock production generates less food per unit area of land than crop production because A energy is gained between trophic levels of the food chain B livestock production degrades natural resources C energy is lost between trophic levels of the food chain D it is easier to grow crops than raise livestock in difficult habitats. 15. The table shows optimum, maximum and minimum temperatures for the growth of some crop plants. Temperature (°C) Crop Optimum Maximum Minimum Maize 22–26 32–34 20–22 Wheat 20–25 36–38 5–7 Rice 30–33 37–40 18–22 Potato 15–20 28–34 12–14 Soyabean 25–28 37–40 10–14 Which of the following predictions is supported by the evidence in the table? A Maize will grow at lower temperatures than soyabean. B Rice will grow at higher temperatures than soyabean. C Rice will grow in a narrower range of temperatures than maize. D Wheat will grow in a wider range of temperatures than potato. [Turn over