Science

• Evolution refers to a change in the characteristics of organisms over time
• Fossil records are the remains of organisms preserved in different ways
• Petrification occurs when minerals in groundwater are absorbed by tissues of dead organisms, causing them to harden as rock
• A paleontologist is a scientist who studies fossils
• Anatomical evidence supports evolution by comparing body structures of different organisms
• Homologous evidence shows similarities in body structures of different organisms with different functions
• Vestigial organs are parts of organisms significantly reduced in size over time
• Embryological evidence shows similarities in the embryonic stages of closely related organisms
• Molecular evidence supports the idea that related organisms have more similarities in their DNA
• Amino acid sequencing is used to compare proteins and determine the sequence of amino acids in a polypeptide
• The theory of the inheritance of acquired traits by Jean-Baptiste Lamarck suggests organisms change to survive and can pass on modified traits to offspring
• The theory of evolution by natural selection by Charles Darwin states organisms must be fit to survive and reproduce successfully
• Microevolution occurs when allele frequencies in a group undergo changes
• Non-random mating occurs when organisms choose to reproduce based on certain characteristics
• Gene flow is the migration of organisms to and from a population, affecting its gene pool
• Genetic drift is when changes in the gene pool occur due to random chances
• Mutation is abnormalities or mistakes in DNA typically made during DNA replication
• Natural selection is the process by which nature selects certain traits over others in a population to better adapt organisms to their habitat
• Directional selection shifts allele frequencies caused by changes in the environment
• Stabilizing selection happens when a middle form of trait is chosen and extreme forms are eliminated
• Disruptive selection occurs when extreme forms of traits are favored more than others
• Macroevolution refers to large-scale changes leading to the evolution of organisms from simple to complex
• Adaptive radiation refers to the evolution of organisms into several new ones living differently from the original population
• Divergent evolution happens when two isolated populations evolve separately
• Speciation is a process where a new species is created
• Convergent evolution happens when unrelated organisms appear similar
• Coevolution occurs when two different interacting organisms evolve jointly due to changes in the other organisms
• Biodiversity refers to the variety of life found in an area
• Biological levels of organization include organism, population, community, ecosystem, biome, and biosphere
• A niche is the set of requirements each species needs to grow and reproduce
• Food chain is a linear sequence of how energy and nutrients pass from one organism to another
• Primary productivity is the amount of energy produced by photosynthetic organisms in a community
• The littoral zone is the region of a lake with rooted vegetation
• The limnetic zone is the region of a lake with no rooted vegetation
• Diversity maintenance optimizes food production in agriculture, water purification, and the production of biofuels and wood in forests
• Natural ecosystems are composed of biotic and abiotic components
• Terrestrial ecosystems are land-based interactions of biotic and abiotic factors in a given geographic area
• Aquatic ecosystems are water-based and can be freshwater or marine ecosystems
• Levels of salinity are higher in marine ecosystems than in freshwater systems
• An artificial ecosystem is a system of organisms within a given area that is not self-sustaining and can be destroyed without human intervention