Scottish Highers · Higher Biology

Ecology, Evolution and Immunity

35 practice questions, each with the answer and an explanation.

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Random questions from this topic, one at a time. You see the answer and the explanation straight after each one.

All 35 questions

  1. Why is the energy transfer between trophic levels in a food chain usually low?
  2. A producer fixes 12000 kJ of energy. The primary consumer receives 1200 kJ. What is the percentage efficiency of energy transfer?
  3. Which of the following is a density-dependent factor affecting a population?
  4. What is meant by biodiversity?
  5. Isolation of populations can lead to speciation. What is the term for speciation caused by a geographical barrier?
  6. Which statement describes stabilising selection?
  7. What is a monoclonal antibody?
  8. A new vaccine gives long-term protection. Which cells make this possible?
  9. What is the effect of the Hardy-Weinberg conditions being met?
  10. In a pedigree, two unaffected parents have an affected daughter. Which pattern of inheritance does this show?
  11. A plant breeder crosses two plants that are heterozygous for a gene (Tt x Tt). What proportion of the offspring is expected to be homozygous?
  12. Which type of mutation changes only one amino acid in a protein?
  13. Two species live together and both benefit. What is this relationship called?
  14. Which statement describes interspecific competition?
  15. A student counts species with a pitfall trap and calculates a diversity index. Why should she use random sampling?
  16. Which process increases genetic variation in a population by producing new alleles?
  17. A small group of birds colonise an island and their population differs genetically from the mainland population. What term best describes this effect?
  18. What is allopatric speciation?
  19. What is a sympatric speciation mechanism that occurs in plants?
  20. A phagocyte engulfs a bacterium. Which type of immune response is this?
  21. What is the role of memory lymphocytes?
  22. How does a vaccine give protection?
  23. What is herd immunity?
  24. A restriction enzyme cuts DNA at the sequence GAATTC. A DNA fragment contains this sequence in 3 places. How many pieces does it produce when the fragment is linear?
  25. What is the purpose of a plasmid vector in genetic engineering?
  26. Why is it useful to include an antibiotic resistance gene in a plasmid vector?
  27. A student calculates a sample standard deviation to describe variation in leaf length. What does a small standard deviation show?
  28. In a sampling investigation the mean number of daisies per quadrat in a field is 4.5. The field is 600 m² and each quadrat is 1 m². What is the estimated total number of daisies?
  29. A population of bacteria doubles every 30 minutes. Starting with 100 bacteria, how many will there be after 3 hours?
  30. A gene has two alleles. A cross between two heterozygous individuals gives 120 offspring. How many would you expect to be homozygous recessive?
  31. Which structure carries out the major part of the control of blood glucose by storing glucose as glycogen?
  32. What is meant by a 'sink' in the transport of sugars in a plant?
  33. A pesticide is applied to a population of aphids and 95% die. After several generations the pesticide has little effect. Which factor best explains this?
  34. Which of the following is a density-independent factor affecting a population?
  35. A herbivore population has 5000 individuals and the carrying capacity of the habitat is 5000. What is likely to happen to the population?

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