Grade 012 IEB Life Science Revised TEST EXAM Questions & Answers 2023/2024

Grade 012 IEB Life Science Revised TEST EXAM Questions & Answers 2023/2024 Ecology correct answers The study of the interactions of organisms with their physical and biological environments. Population ecology correct answers The fluctuations in the size of a population and the factors (physical and social) that regulates these fluctuations. Population size correct answers The total number of individuals Natality correct answers birth rate Mortality correct answers death rate Immigration correct answers Individuals moving into a population and staying Emigration correct answers Individuals leaving a population and not returning Closed population correct answers a population that has no immigration and emigration with other populations Environmental resistance correct answers The total number of factors that stop a population from reproducing at its maximum rate. Limiting factors build up this. carrying capacity correct answers The population density that the environment can support. The pop fluctuates around the carrying capacity. Limiting factors correct answers Help to regulate the growth of a population. Density independent factors correct answers Limit growth pop. Results natural factors, not bcuz of no. of organisms. PHYSICAL FACTORS (temp, humidity, rainfall) CATASTROPHIC EVENTS (flood, fire, earthquake) Density dependent factors correct answers Greater effect pop density is high. More crowded: COMPETE (resources-food,water,light,oxygen,space,shelter) PREDATORS (more easily found) DISEASE (spread easily) stable population correct answers Numbers decrease-size exceeds cc Increase-fall below cc FLUCTUATES Unstable population correct answers Pop far exceeds cc Habitat: deteriorating rapidly, low cc, not being able to support pop, decrease, extinct Direct method correct answers Counting every single individual in pop. CENSUS. Organisms=large. Area=not too large. Individuals=slow, stationary, stay in fixed position. Area too large=aerial pics, helicopters.