YIJC [H2] ETB_Impact of Climate Change (N) Part 2 (Vetted)

9744 H2 BIOLOGY LECTURE NOTES | JC 2 Impact of Climate Change on Animals & Plants 30 Extension Topic B Impact of Climate Change on Animals and Plants Part 2 Learning Outcomes (e) Explain how temperature changes impact insects, including increased temperature leading to increased metabolism and the narrow temperature tolerance of insects. (f) Outline the life cycle of Aedes aegypti as an example of a typical mosquito vector. (g) Outline the development of viral dengue disease in humans, including host -pathogen interactions, human susceptibility to the virus, pathogen virulence, transmission, and drug resistance. (h) Explain how global warming affects the spread of mosquito -borne infectious diseases, including malaria and dengue, beyond the tropics. (i) Discuss the effects of increased environmental stress (including increased temperatures and more extreme weather conditions) as a result of global climate change, on habitats, organisms, food chains and niche occupation. (j) Discuss how climate change affects the rich biodiversity of the tropics including the potential loss of this rich reservoir for biomedicines and genetic diversity for food. Lecture Outline 1) Impact of Temperature Change on Insects 1.1 Effect on Insects Growth, Development & Activity 2) Life cycle of a Mosquito Vector 2.1 The Aedes aegypti mosquito 2.2 Life cycle of Aedes aegypti 3) Viral Dengue Disease 3.1 Transmission 3.2 Pathogenesis 3.3 Treatment 3.4 Prevention 4) Effect of Global Warming on Mosquito-borne Diseases 4.1 Effect on Insect Distribution 4.2 Spread of Mosquito-borne Diseases 5) Effects of Environmental Stress 5.1 Impact on Distribution of Animals and Plants 5.2 Impact on Breeding Success of Animals and Plants 6) Effect on Biodiversity 6.1 Loss of Biomedicines 6.2 Loss of Genetic Diversity of Foods

31 Learning Outcome (e): Explain how temperature changes impact insects, including increased temperature leading to increased metabolism and the narrow temperature tolerance of insects. 1 IMPACT OF TEMPERATURE CHANGE ON INSECTS 1.1 Effect on Insect Growth, Development & Activity The body temperature of ectotherms1 fluctuates with environmental temperatures, and basic physiological functions such as locomotion, growth and reproduction are strongly influenced by environmental temperature. Growth and development are fuelled by metabolism. Metabolic rate is the result of many different biological reactions which are catalysed by enzymes. Thus, temperature controls metabolism through its effect on the rates of these enzyme-catalysed biochemical reactions. Fig. 1.1 Global changes in temperature and corresponding changes in metabolic rates of ectotherms In ectotherms, rates of both somatic growth and ontogenic development 2 increase with increasing temperature. A 10°C temperature increase results in approximately 2.5 -fold increase in