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| Question | Answer |
| BIOLOGY: BLUEPRINT OF LIFE: FOCUS 1 > outline the impact on the evolution of plants and animals of changes: in physical conditions in the environment, in chemical conditions in the environment and competition for resources. | :D |
| What is evolution? | Evolution is the change in a population over time. |
| What is the mechanism for evolution? | Natural selection |
| In a population, individuals are characterised by _______ _________. | Inherited traits |
| What happens in a changing environment? | The species experiences the change in an environment which can be physical or chemical; in such a situation, certain traits have an advantage: these survive, breed and pass on these inherited traits to their offspring and over time, this trait becomes common = population evolves. |
| List three reasons for evolution: | - Change in the physical conditions of environment - Change in chemical conditions of environment - Competition for resources |
| Provide examples of physical changes in the environment. | - Change in wind, slope, water availability, temperature, availability of light, tides, rainfall. |
| Provide examples of chemical changes in the environment. | - presence or absence of gases in the environment = oxygen, CO2, pH, concentration of salt etc |
| Provide examples of competition for resources. | - In plants: competition for light, water, soil nutrients. - In animals: compete for breeding territory, food, water, shelter, mates. |
| Describe the nature of adaptions in environmental changes and evolution. | - Individuals do not develop adaptions in response to environmental change. - They already possess the inherited random variation = advantage under new conditions. |
| What is an adaption? | Adaptation: enables organism to cope better with the selective pressure conferred by a changed environment and out compete those organisms that do not possess it. |
| Provide a case example of evolution caused in an animal by a physical change in the environment. | - Plate tectonics: Australia has been moving north for 25 million years, therefore = hotter, drier, increased woodland + grassland. - Effect on kangaroo species: The ancient kangaroo was small with generalised molars. - Evolution of kangaroos: large with specialised high crested molars for eating grass. - Fewer but longer toes for hopping instead of galloping (faster escape from predators) |
| Provide an example of evolution occurring in an insect caused by a physical change in the environment. | - Peppered Moth in England - Industrialised time in 19th century = pollution - pepper moth with dark colours = survive longer because they can camouflage in dark, sooty environment - Gene for darker colour passed on = common - Lighter coloured months: eaten by birds. - However, once population decreased, light coloured moths predominated. |
| Provide a case example of a plant evolving due to a physical change in the environment. | -Bushfires in Australia due to lightning strikes - Only plants adapted to fire can survive, i.e. eucalyptus. |
| Provide examples of chemical change cases in plants causing evolution: | - Soil ph change = significant effect on plant life. - Mining = evolution of plant types which are tolerant to heavy mineral wastes. - Increase in soil salinity = more soil tolerant plants. - Erosion and leeching caused by change in composition of soil due to high temperatures in Australia = eucalyptus survives. |
| Provide an example of a case in which chemical change caused evolution in an insect. | - Insecticide DDT killed mosquitos. - However, some survived as they had a DDT resistant gene --> passed onto offspring = common - Now, DDT has to be used in high concentrations to kill mosquitos. |
| Describe how chemical changes can cause resistant organisms in antibiotics. | - Herbicides, insecticides and antibiotics lead to the evolution of resistant organisms. = staphylococcus bacteria = resistant to penicillin. |
| Competition for resources can occur between ______ or _______ species. | Competition for resources can occur between SAME or DIFFERENT species. |
| Provide an example of competition for resources causing evolution. | - In Australia, introduction of non-native species such as fox, rabbit, feral cats, cane toads lead to the extinction of native species such as the burrowing bettong. |
| Describe how giraffes evolved due to competition for resources. | - Ancestral giraffes had to compete for higher leaves on trees as the environment changes - Longer neck = advantageous - Passed on 'long neck' gene = lead to the long necked species of giraffes. |
| Describe the case study: Evolution of kangaroos | - Small kangaroos (size of rabbits) in Central Australia, 25 million years ago. - Environment then: cool, moderate rainfall, freshwater lakes, rivers, heavily forested. - Middle of the Miocene (10-12million years ago), Australia moved north = heated up = drier. - Forests = eucalyptus + grassland. - Kangaroos increased = evolved into larger kangaroos. - Fewer but longer toes for hopping instead of galloping to escape predators. - Specialised high crested Molars adapted to grazing. |
| What are the different types of evidence for evolution. | - Palaeontology - Comparative anatomy - Comparative embryology - Biochemical similarities - Biogeography |
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