Ecology Population Growth and Regulation 2

Question 1

Which equation correctly represents the net reproductive rate (R0) in a population?

Accepted Answer

R0 = Σ(lx × mx)

Answer

R0 is calculated by summing the products of age-specific survivorship (lx) and fecundity (mx) across all age classes.

Question 2

A population grows from 500 to 550 individuals in one year. What is the per capita growth rate (r) approximately?

Accepted Answer

0.095

Answer

r ≈ ln(550/500) = ln(1.1) ≈ 0.095 per year using the continuous growth formula.

Question 3

What does a survivorship curve Type II indicate about a population?

Accepted Answer

Constant mortality rate at all ages

Answer

Type II survivorship curves are linear on a log scale, indicating a constant probability of dying at any age regardless of age class.

Question 4

Scramble competition occurs when limited resources are divided among all competitors such that:

Accepted Answer

Everyone gets an insufficient share and many die

Answer

In scramble competition, resources are shared equally but often below the threshold needed for survival, leading to widespread mortality.

Question 5

Which demographic concept describes the time it takes a population to double in size under exponential growth?

Accepted Answer

Doubling time (td = ln2 / r)

Answer

Doubling time is calculated as ln(2) divided by the intrinsic rate of increase (r), approximately 0.693/r.

Ecology Practice Test