Skip over navigation
Biology Measurement Challenge
Age 14 to 16
Challenge Level 
The average dimension for each of the following objects is given in the table below:
| Length | Cross - Sectional Area | Volume | Modelling by which solid? | |
| Mitochondria | 1 $\mu$m | 0.79 $\mu$m$^2$ | 0.79 $\mu$m$^3$ | Cylinder |
| Arabis voch pollen | 30 $\mu$m | 706.9 $\mu$m$^2$ | 14137 $\mu$m$^3$ | Sphere |
| Ring stage of Plasmodium falciparum | 1.5 $\mu$m | 0.79 $\mu$m$^2$ | 0.03 $\mu$m$^3$ | Ring |
| Tuberculosis bacterium | 2 $\mu$m | 0.12 $\mu$m$^2$ | 0.24 $\mu$m$^3$ | Cylinder |
| Human red blood cell | 8 $\mu$m | 50 $\mu$m$^2$ | 100 $\mu$m$^3$ | Disc |
| Human nerve cell | 2 $\mu$m | 3 $\mu$m$^2$ | 0.3 $\mu$m$^3$ | Disc |
| The eye of a needle | 1 mm | 1 mm$^2$ | 0.1 mm$^3$ | Cuboid |
| Cat hair | 3 cm | 0.3 mm$^2$ | 9 mm$^3$ | Cylinder |
| Snowflake crystal | 1 cm | 0.79 cm$^2$ | 0.17 cm$^3$ | Sphere |
Therefore, we can roughly rank these objects by length, volume and cross - sectional area.
You may also like
Ladder and Cube
A 1 metre cube has one face on the ground and one face against a wall. A 4 metre ladder leans against the wall and just touches the cube. How high is the top of the ladder above the ground?
Archimedes and Numerical Roots
The problem is how did Archimedes calculate the lengths of the sides of the polygons which needed him to be able to calculate square roots?
