Problem 7 - Biology: The Dynamic Science

Question

According to the logistic model of population growth, the absolute number of individuals by which a population grows during a given time period: a. gets steadily larger as the population size increases. b. gets steadily smaller as the population size increases. c. remains constant as the population size increases. d. is highest when the population is at an intermediate size. e. fluctuates on a regular cycle.

Step-by-Step Solution

Answer

The correct option is d) the absolute number of individuals by which a population grows during a given time period is highest when the population is at an intermediate size.

Step 1: Understanding the Factors

In the logistic model of population growth, the factors that matter include the size of the population and the availability of resources (carrying capacity). As the population increases, there are changes in the rate at which it grows.

Step 2: Looking at the Options

Among the options a) to e), we need to identify which one correctly describes how the absolute number of individuals by which a population grows changes as the population size increases. This inherently means we're looking at rate of change, not the actual population size at any given moment.

Step 3: Choosing the Correct Option

In logistic growth, the rate of population growth gets larger when population size initially increases from a small number (option a)), but it doesn't steadily get larger. It eventually slows down and gets reduced due to resource constraints (opposite of option b)). The growth does not remain constant as population size increases (option c)) nor does it fluctuate on a regular cycle (option e)). This leaves us with option d), suggesting that the population growth is highest at an intermediate size. This best describes the nature of logistic growth, which follows an S-shaped curve with the steepest slope (fastest rate of population growth) typically in the middle.