Back to 课程

Biology AS OCR

0% Complete
0/0 Steps
  1. 1-1-practical-skills-written-assessment AS
    7 主题
  2. 1-2-practical-skills-endorsement-assessment AS
    16 主题
  3. 2-1-cell-structure AS
    9 主题
  4. 2-2-biological-molecules AS
    17 主题
  5. 2-3-nucleotides-and-nucleic-acids AS
    8 主题
  6. 2-4-enzymes AS
    9 主题
  7. 2-5-biological-membranes AS
    9 主题
  8. 2-6-cell-division-cell-diversity-and-cellular-organisation AS
    11 主题
  9. 3-1-exchange-surfaces AS
    7 主题
  10. 3-2-transport-in-animals AS
    12 主题
  11. 3-3-transport-in-plants AS
    11 主题
  12. 4-1-communicable-diseases-disease-prevention-and-the-immune-system AS
    16 主题
  13. 4-2-biodiversity AS
    10 主题
  14. 4-3-classification-and-evolution AS
    15 主题
课 Progress
0% Complete

Exam code:H020

Types of adaptations

  • The term adaptation can be defined as:

A characteristics that aids an organism’s survival in its environment

  • Adaptations can be:

    • anatomical

      • Physical features of an organism

      • E.g. the white fur of a polar bear provides camouflage in the snow so it has less chance of being detected by prey

    • physiological

      • Biological processes within an organism

      • E.g. mosquitos produce chemicals that stoa host’s blood from clotting when they bite so that they can feed more easily

    • behavioural

      • The way an organism behaves

      • E.g. reptiles bask in the sun to absorb heat

Types of adaptations table

Types of adaptations table, downloadable AS & A Level Biology revision notes

Convergent evolution

  • Organisms from different taxonomic groups may show similar adaptations even though they do not share a recent common ancestor

  • Shared adaptations between unrelated organisms arise due to convergent evolution

  • Convergent evolution occurs by natural selection as follows:

    • two species live in different parts of the world with similar environments

    • the species deal with the same selection pressures

    • the same characteristics are advantageous in the two environments, so individuals with these characteristics are more likely to survive and reproduce

    • over time the advantageous characteristics become widespread in both populations

Examiner Tips and Tricks

You may be asked to identify whether an adaptation is anatomical, physiological or behavioural so make sure you have a good grasp of the differences between them. Learning an example for each can sometimes help you, as you then have them for comparison in an exam.

Responses

您的邮箱地址不会被公开。 必填项已用 * 标注