Ecology Population Growth Models 3

Question 1

Which type of survivorship curve is characterized by high survival throughout life followed by rapid die-off in old age?

Accepted Answer

Type I

Answer

Type I survivorship curves (e.g., humans, elephants) show most individuals surviving to old age before experiencing a steep decline in numbers.

Question 2

A population modeled with discrete time steps uses the geometric growth equation N(t+1) = λN(t). When is this population declining?

Accepted Answer

λ < 1

Answer

When λ (the finite rate of increase) is less than 1, each time step produces fewer individuals, so the population shrinks toward extinction.

Question 3

Stochastic models of population growth are most important for predicting extinction risk in:

Accepted Answer

Very small populations where chance events matter greatly

Answer

In small populations, random variation in birth, death, and environmental conditions can drive extinction even when deterministic models predict persistence.

Question 4

The net reproductive rate R₀ = 1 means a population is:

Accepted Answer

Exactly replacing itself each generation

Answer

R₀ = 1 indicates each individual replaces itself exactly once per generation, meaning the population is stable (neither growing nor shrinking).

Question 5

Which of the following is a density-independent factor affecting population growth?

Accepted Answer

A sudden volcanic eruption

Answer

Volcanic eruptions (and other natural disasters) affect populations regardless of their density, making them density-independent limiting factors.

Ecology Practice Test

Ecology Practice Test

Ecology Population Growth Models 3