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• Outline the theory of evolution by natural selection.

  Variation, survival, reproduction, inheritance
• Individuals of a species show a wide range of variation for a characteristic
• Individuals with traits most suited to their environment are more likely to survive and breed.
• Steps in the process of natural selection

  1️⃣ Variation in a species

  2️⃣ Traits suited to the environment increase survival

  3️⃣ Successful breeding

  4️⃣ Inheritance of desirable traits
• The desirable characteristic that enables survival is passed onto offspring through inheritance
• Why was Darwin’s theory of evolution not accepted initially?

  Belief in creationism
• Darwin’s theory lacked sufficient evidence to prove the mechanism of inheritance.
• What was Jean-Baptiste Lamarck’s theory of inheritance?

  Inheritance of acquired characteristics
• Lamarck’s theory proposed that changes during an organism’s lifetime can be inherited.
• Speciation occurs when two populations become so varied that they cannot interbreed to produce fertile offspring.
• What is the definition of a species?

  Organisms producing fertile offspring
• A species is defined as a group of organisms that can interbreed to produce fertile offspring.
• Steps in speciation through geographic isolation

  1️⃣ Populations are geographically separated

  2️⃣ Interbreeding is prevented

  3️⃣ Different mutations occur due to selection pressures

  4️⃣ Populations evolve and cannot interbreed
• Genetic variation is important in speciation because it produces phenotypic variation.
• How did Mendel study inheritance?

  Pea breeding experiments
• Mendel analyzed the ratios of traits in offspring to understand inheritance.
• Mendel’s work was not recognized until after his death because he could not explain the mechanism of inheritance.
• State two kinds of evidence used to show evolution.

  Fossils and antibiotic resistance
• Fossils are formed when organisms decay completely in the presence of oxygen.

  False
• Steps in the formation of fossils

  1️⃣ Lack of decay due to specific conditions

  2️⃣ Replacement of organic parts by minerals

  3️⃣ Preservation of traces in sediment
• How do fossils act as evidence for evolution?

  Show changes over time
• Branches in evolutionary trees indicate where speciation has occurred.
• Extinction occurs when there are no remaining individuals of a species alive.
• State two factors that may lead to extinctions.

  New disease and predation
• Bacteria evolve quickly due to their fast reproduction rate.
• Steps in the development of antibiotic resistance in bacteria

  1️⃣ Mutations in bacteria produce genetic variation

  2️⃣ Resistant strains survive antibiotic treatment

  3️⃣ Resistant strains reproduce

  4️⃣ Population of resistant strains increases
• Why are resistant strains of bacteria dangerous?

  No effective treatment
• An example of a resistant strain of bacteria is MRSA.
• Inappropriate use of antibiotics, such as for viral diseases, contributes to antibiotic resistance.
• Why is it difficult to keep up with emerging resistant strains of bacteria?

  High cost and time