Tài liệu Khoa Học Tự Nhiên

Interspecific competition: resources are in short supply Species interaction is -/- Competitive exclusion principle: Two species cannot coexist in a community if their niches are identical. The one with the slight reproductive advantage will eliminate the other Resource partitioning: differences in niches that enable similar species to coexist

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Clumped – most common; near required resource Uniform – usually antagonistic interactions Random – unpredictable spacing, not common in nature

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cell body: contains nucleus & organelles dendrites: receive incoming messages axons: transmit messages away to other cells myelin sheath: fatty insulation covering axon, speeds up nerve impulses synapse: junction between 2 neurons neurotransmitter: chemical messengers sent across synapse Glia: cells that support neurons Eg. Schwann cells (fo...

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The components of a virus. The differences between lytic and lysogenic cycles. How viruses can introduce genetic variation into host organisms. Mechanisms that introduce genetic variation into viral populations.

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Restriction enzymes (restriction endonucleases): used to cut strands of DNA at specific locations (restriction sites) Restriction Fragments: have at least 1 sticky end (single-stranded end) DNA ligase: joins DNA fragments Cloning vector: carries the DNA sequence to be cloned (eg. bacterial plasmid)

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Make up 75% of repetitive DNA Stretches of DNA that can be moved from one location to another in genome Discovered by Barbara McClintock – corn breeding experiments 2 Types: Transposons Retrotransposons

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Linnaeus: founder of taxonomy; binomial nomenclature Domain – Kingdom – Phylum – Class – Order – Family - Genus – Species (Dear King Philip Came Over For Good Spaghetti) Domains = Bacteria, Archaea, Eukarya Classification based on anatomy & morphology

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Evolution is change in species over time. There is overproduction of offspring, which leads to competition for resources. Heritable variations exist within a population. These variations can result in differential reproductive success. Over generations, this can result in changes in the genetic composition of the population. Remember: Individ...

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Point mutations: changes in one base (eg. sickle cell) Chromosomal mutations: delete, duplicate, disrupt, rearrange  usually harmful Sexual recombination: contributes to most of genetic variation in a population Crossing Over (Meiosis – Prophase I) Independent Assortment of Chromosomes (during meiosis) Random Fertilization (sperm + egg)

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Many new species arise from a single common ancestor Occurs when: A few organisms make way to new, distant areas (allopatric speciation) Environmental change  extinctions  new niches for survivors Eg. Hawaiian archepelago

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