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A-Level Edexcel Biology Units in Calculations

Review A-Level Edexcel Biology units in calculations through mass, volume, length, energy, temperature and rate conversions in biological contexts.

Syllabus
Pearson Edexcel International Advanced Subsidiary/Advanced Level
Course
Biology XBI11/YBI11
Level
AS

Exam points

  • convert biological measurements between cm, µm, cm^3 and dm^3 before calculating
  • use correct compound rate units such as nmol mg^-1 min^-1 in data questions
  • convert energy, mass or temperature values and round answers to stated precision

A.0.1—Units in calculations question 1

[Maximum number: 1]

An abdominal aortic aneurysm (AAA) is a swelling of the aorta in the abdomen due to weakening of the wall of the aorta. Patients with an AAA frequently have atherosclerosis. An AAA can be fatal if the aorta bursts causing internal bleeding. The diagram shows an AAA.

Figure for Question A.0.1—Units in calculations question 1 — Edexcel A-Level Biology AS

The presence of an AAA can be detected by scanning the abdomen. The image shows a scan of a healthy abdominal aorta.

Figure for Question A.0.1—Units in calculations question 1 — Edexcel A-Level Biology AS

An aorta with a diameter greater than 5.5 cm is classed as a large AAA. Calculate how many times wider this large AAA is than the aorta with a diameter of 17.3 mm . Give your answer to three significant figures.

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