Question

Calculate the number of cells in a hummingbird assuming it weighs 10-2 kg

Answer 1

A hummingbird weighing 10^-2 kg contains approximately one trillion cells, assuming the average cell is ten times the mass of a bacterium. For a human weighing 70 kg with the same assumption, it would contain around 7 quadrillion cells.

Step-by-step explanation:

To calculate the number of cells in a hummingbird assuming it weighs 10-2 kg and considering the mass of an average cell is ten times the mass of a bacterium, we first need to establish the average mass of a bacterium. From the reference information given, we understand that the mass of a bacterium is on the order of 10-15 kg. Therefore, the average cell mass would be 10 times this, which is 10-14 kg.

Next, we divide the total mass of the hummingbird by the mass of one of its cells to determine the number of cells:

Number of cells = Mass of hummingbird / Mass of one cell
Number of cells = 10-2 kg / 10-14 kg
Number of cells = 1012

Therefore, a hummingbird that weighs 10-2 kg contains approximately one trillion (1012) cells.

To address part (b) of the question, assuming a human weighs about 70 kg and also assuming the mass of a human cell is ten times the mass of a bacterium (10-14 kg), we can perform a similar calculation:

Number of cells in a human = Mass of human / Mass of one cell
Number of cells in a human = 70 kg / 10-14 kg
Number of cells in a human = 7 x 1015

This suggests that a human has around 7 quadrillion (7 x 1015) cells.

Answer 2

A popular assumption is that the mass of a cell s 10 times the mass of a bacterium, which is about 10⁻¹² g.
Therefore, one cell of the humming bird has a mass of about 10⁻¹¹ g.

The number of cells in a hummingbird weighing 10⁻² g is
10⁻²/10⁻¹¹ = 10⁹

Answer: 10⁹ or a billion.