Classification and Biology

• What are the two main plant groups in classification?

  Flowering plants and non-flowering plants (e.g. mosses, ferns).
• What are the two main animal groups in classification?

  Invertebrates (no backbone) and vertebrates (with backbone).
• Why do scientists classify organisms?

  To group them by similarities, avoid confusion with common names, and enable accurate identification.
• What is binomial nomenclature?

  The scientific naming system using *Genus species* (e.g. *Homo sapiens*).
• What is a morphological adaptation?

  A physical feature that helps an organism survive (e.g. thick fur in polar bears).
• What is a behavioural adaptation?

  An action or habit that helps an organism survive (e.g. birds migrating in winter).
• Name 3 resources that animals compete for.

  Food, water, mates (also shelter).
• Name 3 factors that affect population size.

  Competition, predation, disease, pollution.
• Define biodiversity.

  The variety of different species and the number of individuals in an area.
• Why is biodiversity important?

  It supports stable ecosystems, provides resources like food and medicine, and maintains ecological balance.
• How can biodiversity be protected?

  Legislation, conservation, breeding programmes, protected habitats.
• What is a quadrat used for?

  To estimate the abundance of plant species or in a habitat.
• What is the importance of random sampling?

  It avoids bias and gives a more accurate picture of the whole habitat.
• What is the purpose of repeating samples?

  To increase reliability and accuracy of results.
• What is the capture–recapture formula for estimating population size?

  Number in first sample × Number in second sample ÷ Number of marked recaptures
• Name one assumption made when using capture–recapture.

  No births, deaths, immigration/emigration, and marks don’t affect survival or behaviour.
• What is biological control?

  Using a natural predator or disease to control pest populations.
• What is a risk of biological control?

  The control species might harm non-target species or become invasive.
• What is an alien species?

  A species introduced to a new area where it does not naturally occur.
• Why are alien species sometimes a problem?

  They can outcompete native species, spread disease, or disrupt ecosystems.
• Classification system

  • Kingdom
  • Phylum
  • Class
  • Order
  • Family
  • Genus
  • Species
• Predator

  An animal that hunts and eats another for food.
• Prey

  An animal that is eaten by a predator.
• Pest

  An organism that eats a crop plant.
• Native species

  An organism that lives in the country.
• Invasive species

  An alien organism that has had a negative effect on the native species.
• Quadrat sampling steps

  1. Randomly throw a quadrat.
  2. Count the different species and the number of each in each quadrat.
  3. Take a mean number of each species of plants from all the quadrats collected.
  4. Multiply up to estimate how many in the whole area.
• Capture/recapture steps

  1. Carefully collect organisms found in 1 area without trampling habitat or leaving litter.
  2. Mark the organisms and return them to the same area they were collected from.
  3. Leave time for organisms to reintegrate into their community.
  4. Return and again collect as many organisms as found, collect as those already marked and unmarked samples.
  5. Use an equation to calculate the estimated population size.