Edexcel IGCSE Biology Standard-form Numbers

Edexcel IGCSE Biology Standard-form Numbers
Edexcel IGCSE Biology syllabusBiology 4BI1Issue 3 (2024)

Practise Edexcel IGCSE Biology standard-form numbers by converting biological quantities into powers of ten for cells, nitrogen and nerve impulses.

How this is tested

  • Calculate red blood cell totals and express the result in standard form.
  • Add or convert large biological quantities such as nitrogen masses using powers of ten.
  • Calculate nerve impulse time and write the answer in standard form seconds.

Question 4(c)

[Maximum number: 2]

The diagram shows two samples of blood seen using a high power microscope.
One sample is of normal blood and the other sample is from a patient with a blood condition.

Figure for Question 4(c) — Edexcel IGCSE Biology

In a healthy person 1 cm31 \mathrm{~cm}^{3} of blood contains 5.0×1095.0 \times 10^{9} red blood cells.

An adult has 5.0 litres (5.0dm3)\left(5.0 \mathrm{dm}^{3}\right) of blood in their body.
Calculate the number of red blood cells in the body of a healthy adult.
Give your answer in standard form.
[1dm3=1000 cm3]\left[1 \mathrm{dm}^{3}=1000 \mathrm{~cm}^{3}\right]
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