In a culture medium, there were 50 Euglena. Within 24 hours, 20 were added through the process of reproduction and mean while 8 were died. What is the growth rate of Euglena (in per individual per day) in that medium?

Solution:

The initial population of Euglena (N) = 50.

Number of Euglena added through reproduction (births, B) = 20.

Number of Euglena that died (deaths, D) = 8.

Time period (t) = 24 hours = 1 day.

The net increase in population (ΔN) = Births - Deaths = 20 - 8 = 12 individuals.

Growth rate (r) is defined as the change in population size per unit time per initial individual. It can be calculated as:

r = (ΔN / N) / t

Substituting the values:

r = (12 / 50) / 1

r = 0.24 / 1

r = 0.24 per individual per day.

Therefore, the growth rate of Euglena in that medium is 0.24.