Topic 4: Natural Selection & Genetic Modification

• Who independently proposed the idea of natural selection alongside Darwin?

  Alfred Russel Wallace
• What is the significance of Alfred Russel Wallace's observations?

  They provided further evidence to support the theory of natural selection.
• What are antibiotic-resistant bacteria?

  Bacteria that mutate to become resistant to an antibiotic.
• How do antibiotic-resistant bacteria survive and reproduce?

  They mutate and pass on their antibiotic resistance rapidly.
• What is Archaea?

  One of the three domains consisting of primitive bacteria in extreme environments.
• What is Ardi?

  A 4.4-million-year-old female hominid fossil.
• What phenotypic traits does Ardi exhibit?

  Characteristics of both humans and apes.
• What is Bacillus thuringiensis (Bt)?

  A soil-borne bacterium that secretes a toxin to kill insect larvae.
• How is the gene for toxin production in Bt used in agriculture?

  It can be introduced into the DNA of crop plants for insect resistance.
• What is the definition of biological control?

  The introduction of a new organism to control a pest or pathogen.
• What is carbon-14 dating used for?

  Estimating the age of carbon-containing material found alongside archaeological remains.
• Who developed the theory of evolution by natural selection?

  Charles Darwin
• What is classification in biology?

  The organization of organisms into groups based on characteristics and structure.
• What is competition in an ecosystem?

  When different organisms compete for the same resources.
• What is the role of competition in evolution?

  It limits population size and stimulates evolutionary change.
• What does the domain Eukarya consist of?

  All eukaryotic organisms.
• What is evolution?

  The gradual change in inherited traits within a population over time.
• What are fertilizers?

  Natural or artificial materials added to soils to improve plant growth.
• What is the five kingdom classification system?

  The classification of organisms into five major kingdoms: Animalia, Fungi, Plantae, Prokaryotae, and Protoctista.
• Who developed the theory of speciation and evolution by natural selection?

  Alfred Russel Wallace
• What are fossils?

  The remains of dead organisms found in rocks millions of years old.
• What idea did Wallace propose regarding individuals without survival characteristics?


  They would die out due to environmental changes.
• With whom did Wallace publish joint studies?

  Charles Darwin
• What is a genetically modified (GM) organism?

  An organism that has had its genome altered.
• What was the significance of the publication of 'On the Origin of Species'?

  Darwin received credit for the theory of evolution.
• What is genetic engineering?

  The modification of an organism's genome by inserting a desired gene from another organism.
• What was one of Wallace's important works related to animals?

  Warning coloration in animals
• What is a genome?

  The complete genetic material of an organism.
• What is ligase?

  An enzyme that joins the sticky ends of DNA and vector DNA.
• How has our understanding of evolution changed over time?

  It has been enhanced by much more evidence.
• Who is Lucy in the context of hominid fossils?

  A 3.2 million-year-old female hominid fossil.
• What phenotypic traits does Lucy exhibit?

  More human-like traits than Ardi.
• What are the steps in the process of speciation?

  1. Variation exists within a population due to genetic mutations.
  2. Alleles providing survival advantages are selected for.
  3. Populations can become isolated by physical barriers.
  4. Different alleles may be advantageous in the new environment.
  5. Selection of different alleles increases genetic variation.
  6. New species form when populations can no longer breed together.
• What is a mutation?

  A random change in the base sequence of DNA.
• What is the definition of 'survival of the fittest'?

  Organisms with characteristics suited to the environment are more likely to survive and reproduce.
• What happens to the frequency of advantageous alleles over generations?

  It increases within the population.
• What can mutations result in?

  Genetic variants that may be beneficial, damaging, or neutral.
• What was one reason for the controversy surrounding Darwin's ideas?

  It contradicted the belief that God created all species.
• Why was there not enough evidence for Darwin's ideas at the time?

  Few studies had been done on how organisms change over time.
• What is natural selection?

  The process by which advantageous traits increase in frequency over time.