Question

how to calculate average growth rate:
work out the increase/decrease in number of gerbils in that timeframe. for this question, look at how many gerbils there were at week 4 and how many there were at week 8. what is the difference?
then divide that number by the number of weeks (how many weeks are between weeks 4 and 8?).
pop. growth: growth curves
the size of a population of gerbils was measured over a period of 16 weeks. the data collected was used to draw this graph. use it to answer the questions:

1. look at the of this gerbil population. wh of population growth occurre this time period?
2. what is the carrying capacity of the gerbil population?
3. when was the carrying capacity for this population first reached?
4. what was the average growth rate per week bet s 4 - 8?

Explanation:

1. The graph shows a sigmoid (S - shaped) curve. This type of curve represents logistic population growth. Logistic growth occurs when a population grows rapidly at first (exponential - like phase) but then slows down as it approaches the carrying capacity of the environment.
2. The carrying capacity is the maximum number of individuals of a population that an environment can support. On the graph, when the population size stops increasing and levels off, that value is the carrying capacity. Looking at the y - axis (number of gerbils), the value where the curve levels off is 85.
3. The carrying capacity is first reached when the population stops its rapid increase. Looking at the x - axis (time in weeks), the population stops increasing and starts to level off at week 12.

Answer:

1. Logistic population growth.
2. 85 gerbils.
3. Week 12.