PAPER 2 REVISION

• What does interdependence mean in an ecosystem?

  Organisms rely on each other for resources
• What are abiotic factors in an ecosystem?

  Non-living aspects like light and temperature
• What are biotic factors in an ecosystem?

  Factors due to organisms like food and predators
• How can quadrats be used in ecology?

  To estimate population size in an area
• What is a food chain?

  A sequence showing energy flow between organisms
• What are producers in an ecosystem?

  Organisms that produce biomass using sunlight
• What are primary consumers?

  Herbivores that eat producers
• What are apex predators?

  Top predators with no natural enemies
• What does the Pyramid of biomass represent?

  Mass entering the next trophic level
• How do you calculate the percentage of biomass absorbed?

  Percentage = part divided by whole times 100
• Why is food security important?

  Due to increasing population and changing diets
• What is a sustainable fishing method?

  Nets that allow young fish to escape
• What is the carbon cycle?

  The recycling of carbon in ecosystems
• What does biodiversity refer to?

  The variety of different organisms in an ecosystem
• How does human development affect biodiversity?

  It usually results in lower biodiversity
• What is a consequence of deforestation?

  Reduction in biodiversity
• What is the role of carbon dioxide and methane in global warming?

  They contribute to the greenhouse effect
• What is a gene?

  A section of DNA coding for a protein
• What is the Human Genome Project?

  Mapping all human genes and their functions
• What is the difference between genotype and phenotype?

  Genotype is genetic code; phenotype is expression
• How do mutations affect proteins?

  They can result in non-functional proteins
• What are nucleotides?

  Monomers that make up DNA strands
• What is epigenetics?

  Study of gene expression regulation
• What are alleles?

  Different versions of the same gene
• What is a Punnett square used for?

  To predict genetic outcomes of offspring
• What is the probability of a child having blue eyes from two heterozygous parents?

  25% chance of blue eyes
• What is the significance of sex chromosomes?

  They determine the biological sex of an individual
• What is Charles Darwin's theory of evolution?

  Random variation leads to survival and reproduction
• How does epigenetics relate to evolution?

  It shows DNA can respond to environmental changes
• What is bacterial resistance?

  Resistance developed through mutations in bacteria
• Why is it important to complete a course of antibiotics?

  To prevent the development of resistant bacteria
• How does DNA respond to the environment?


  It turns genes on and off as needed
• Who asserted that adaptation is guided by DNA?

  Jean Baptist Lamarck
• What is bacterial resistance evidence of?

  Darwinian evolution
• Why should antibiotics be used sparingly?

  To prevent resistant bacteria from reproducing
• What defines organisms as the same species?

  They can produce fertile offspring
• What did Gregor Mendel discover about characteristics?

  They are determined by units passed to offspring
• What is genetic modification used for?

  To enhance traits without selective breeding
• How is insulin produced using genetic modification?

  Bacteria are modified to produce insulin
• What is golden rice modified to produce?

  Vitamin A