Question

which situation shows a population with a positive growth rate?

• a fish population increases from 100 to 130 individuals in one year.
• a population is spread across a wide mountain range.
• a population has equal numbers of births and deaths.

Explanation:

🆕 New Concept Discovered: Population Growth Dynamics
How populations change in size over time

Step 1: Define positive growth rate

A positive growth rate means that the size of a population is increasing over time. This happens when the number of individuals added to the population (through births and immigration) is greater than the number of individuals leaving the population (through deaths and emigration).

Step 2: Analyze the options

• Option 1: "A fish population increases from 100 to 130 individuals in one year."
• The population size goes up (from 100 to 130). An increase in size indicates a positive growth rate.
• Option 2: "A population is spread across a wide mountain range."
• This describes the geographic distribution (dispersion) of the population, not how its size is changing over time.
• Option 3: "A population has equal numbers of births and deaths."
• If births equal deaths (and assuming no migration), the population size remains constant. This represents a growth rate of zero.

Step 3: Identify the correct situation

The only scenario where the population size is actively increasing is the first option.

Answer:

A fish population increases from 100 to 130 individuals in one year.