paper 2

• What is the focus of OCR GCSE biology paper 2?

  Community level systems, genes, inheritance, and selection
• What does interdependence mean in ecology?

  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 does a food chain illustrate?

  The direction of energy flow in an ecosystem
• What are producers in an ecosystem?

  Organisms that use sunlight to produce biomass
• What are primary consumers?

  Herbivores that eat producers
• What are apex predators?

  Predators with no natural predators above them
• What is the Pyramid of biomass?

  A representation of mass entering trophic levels
• How do you calculate the percentage absorbed by the next trophic level?

  Percentage = (part/whole) × 100
• Why is food security important?

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

  Nets with holes to let young fish escape
• What does biodiversity refer to?

  The variety of different organisms in an ecosystem
• What is a consequence of human development on biodiversity?

  It usually results in lower biodiversity
• What is the impact of deforestation?

  It reduces biodiversity and habitats
• What is the role of carbon dioxide in global warming?

  It contributes to the greenhouse effect
• What is a gene?

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

  It mapped all human genes by 2003
• What is the difference between genotype and phenotype?

  Genotype is the genetic code; phenotype is expression
• What are nucleotides?

  Monomers that make up DNA strands
• How do mutations affect proteins?

  They can result in non-functional proteins
• What is epigenetics?

  The study of gene expression regulation
• What are dominant alleles?

  Alleles that express traits even with others present
• What is a Punnett square used for?

  To predict probabilities of traits in offspring
• What is the significance of the XX and XY chromosomes?

  They determine the sex of an individual
• How does Darwin's theory of evolution explain variation?

  Random variation leads to survival advantages
• What is the role of antibiotics in bacterial resistance?

  They can lead to resistant bacteria if misused
• How does DNA respond to environmental changes?

  It turns genes on and off as needed
• What happened to blind mackerel bred in sunlight?

  They regained fully working eyes and opaque skin
• 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 stronger resistant bacteria from developing
• 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
• How can organisms be genetically modified?

  By altering their DNA directly
• What is golden rice modified to produce?

  Vitamin A
• What is the process of genetic engineering?

  A gene is cut, inserted into a vector, and transferred
• Why must genetic modification occur early in development?

  To ensure the gene is in every cell
• What is cloning?

  Making exact copies of organisms