Unit 4.2a Natural Selection Study Guide 7.11 Organisms and environments. The student knows that populations and species demonstrate variation and inherit many of their unique traits through gradual processes over many generations. The student is expected to: 7.11C identify some changes in genetic traits that have occurred over several generations through natural selection and selective breeding such as the Galapagos Medium Ground Finch (Geospiza fortis) or domestic animals Natural selection changes in genetic traits over many generations based on organism fitness (ability to survive and reproduce) Survival of the Fittest o Changes in genetic traits due to natural selection. (e.g.: claws and beaks of birds, counter-shading in fish, evolution of the wild horse, etc.) Galapagos Medium Ground Finch traits (change in food sources change in bill size) o You do not need to memorize beak types. Page 1 of 7
Selective breeding the breeding of parent organisms by man to produce desired traits in the next generation. Also called Artificial Selection. o Changes in genetic traits due to selective breeding. (e.g.: dog breeds, food crops, bees, livestock) o Undesirable traits can sometimes appear when trying to produce desirable traits in selective breeding. (e.g.: killer bees, hip dysplasia in dogs, white deaf Great Danes and other breed of dogs) Page 2 of 7
7.11B explain variation within a population or species by comparing external features, behaviors, or physiology of organisms that enhance their survival such as migration, hibernation, or storage of food in a bulb Adaptations structural or behavioral features necessary for survival in different environments o Adaptations help organisms survive or reproduce o Includes animal and plant adaptations for movement, getting energy, responding to internal or external stimuli, reproducing You do not need to memorize adaptation images. Examples only Animal External Structural Adaptations o Compare feet/beaks of different types of birds o Compare appendage adaptations for movement and/or feeding o Endoskeletons and Exoskeletons o Body coverings o Scales, skin, feathers, hair Page 3 of 7
Animal Behavioral Adaptations o Mating behaviors o Care of young o Response to danger hiding, fight or flight, etc. o Migration, hibernation, periods of dormancy o Burrowing Hibernation Plant External Structural Adaptations o Autotrophs plants make their own food through photosynthesis o Reproduction - Plants reproduce sexually by seed production from flowers or cones or asexually by budding as with potato plants o Different types of roots and leaves o Seed dispersal o Bulbs - Storage of food in a bulb so that the plant can use it to grow a new stem and leaves in Spring o Attracting pollinators through scent, color, structures for landing Page 4 of 7
Plant Behavioral Adaptations Examples Only This information will be tested in Unit 4.2b so you don t need to memorize for this test. Tropism Stimulus Response Geotropism Gravity Positive roots move toward pull of gravity Negative stems and leaves move against the pull of gravity Hydrotropism Water Positive Roots move toward water source Thigmotropism Touch Positive vines move toward touch of a pole Negative Touch-me-nots plants move away from touch Phototropism Light Positive Plants move toward a light source Page 5 of 7
7.11A examine organisms or their structures such as insects or leaves and use dichotomous keys for identification Plant Dichotomous Keys - Plant parts (roots, stems, leaves, flowers, seeds) are used to classify plants using dichotomous keys. o Plant examples: Trees Leaf descriptions used in dichotomous keys. Study these! Animal Dichotomous Keys - Animal structures (appendages, beaks, etc.) are used to classify animals using dichotomous keys. o Animal examples: Insects, fish, birds Page 6 of 7
7.12 Organisms and environments. The student knows that living systems at all levels of organization demonstrate the complementary nature of structure and function. The student is expected to: 7.12A investigate and explain how internal structures of organisms have adaptations that allow specific functions such as gills in fish, hollow bones in birds, or xylem in plants Plant Internal Structural Adaptations Xylem transport water from the roots to the stems and leaves ONE-WAY ONLY Phloem transports water and food throughout the plant TWO-WAY FLOW Animal Internal Structural Adaptations Gills in fish allow them to obtain oxygen under water Human Eagle Hollow bird bones have less density and help make flight possible. Page 7 of 7