paper 2

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

  Topics four to six of biology
• 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 is a food chain?

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

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

  Herbivores that eat producers like plants
• What are apex predators?

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

  A diagram showing mass at each trophic level
• How do you calculate the percentage absorbed by the next trophic level?

  Percentage = (bit / lot) × 100
• What is food security?

  Ensuring sufficient food availability for populations
• What is a sustainable fishing method?

  Nets that allow young fish to escape
• 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 levels
• What is the impact of deforestation?

  It reduces biodiversity and habitat availability
• What gases contribute to global warming?

  Carbon dioxide and methane
• What is the role of carbon in ecosystems?

  It is recycled when organisms die
• What is the human genome?

  The complete set of genetic material in humans
• What is a gene?

  A section of DNA coding for a protein
• What is a genotype?

  The genetic code stored in DNA
• What is a phenotype?

  How genetic code is expressed in characteristics
• What are nucleotides?

  Monomers that make up DNA strands
• How do base pairs in DNA match?

  A pairs with T, C pairs with G
• What is the role of mRNA in protein synthesis?

  It carries the genetic code to ribosomes
• What can harmful mutations cause?

  Proteins that do not function properly
• What is epigenetics?

  The study of gene expression regulation
• What are alleles?

  Different versions of the same gene
• How do dominant and recessive alleles differ?

  Dominant alleles express traits over recessive ones
• What does a Punnett square predict?

  The probability of offspring traits
• 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 environmental change affect gene expression?

  It can turn genes on and off as needed
• What evidence supports Darwinian evolution in bacteria?

  Bacterial resistance to antibiotics shows adaptation
• Why is it important to complete a course of antibiotics?

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

  It turns genes on and off as needed
• What type of fish regained eyes and skin color?

  Blind translucent skin mackerel
• What did Jean Baptiste Lamarck's theory assert?

  Adaptation is guided by DNA in response to environment
• What is bacterial resistance evidence of?

  Darwinian evolution
• Why should antibiotics be used sparingly?

  To prevent resistant bacteria from reproducing