Question

check your understanding

1. which of these abiotic factors would contribute

to a clumped dispersion pattern in an ecosystem?
select all correct answers.
□ a. unlimited water
□ b. limited water
□ c. high temperatures
□ d. moderate temperatures
□ e. ample rainfall
□ f. limited rainfall

1. an antelope population has a negative population

growth rate. which of the following conditions
must also be true for the population growth rate
to be negative?
o a. births + deaths < immigrations + emigrations
o b. births + deaths > immigrations + emigrations
o c. births + immigrations < deaths + emigrations
o d. births + immigrations > deaths + emigrations

1. a population of yellow warblers, a type of

songbird, experiences a period of exponential
growth. which of these factors would be a density-
dependent limiting factor that could decrease
the carrying capacity of the ecosystem for this
population of songbirds?
o a. a competing species moves into the forest
o b. a period of lower than normal rainfall
o c. a developer fills in a wetland to build an
office park
o d. high winds knock down a quarter of
the trees

Explanation:

1.

Clumped dispersion occurs when resources are limited. Limited water (\(b\)) and limited rainfall (\(f\)) mean organisms cluster around the available water sources. Unlimited water (\(a\)) and ample rainfall (\(e\)) would not cause clumping as resources are abundant. High (\(c\)) and moderate (\(d\)) temperatures are not directly related to clumped dispersion in the context of resource - based clumping.

The formula for population growth rate is \(Population\ growth\ rate=(Births + Immigrations)-(Deaths + Emigrations)\). If \(Births+Immigrations

A competing species (\(a\)) is a density - dependent factor. As the population of yellow warblers grows, competition with the new species for resources (like food, nesting sites) will increase. Lower rainfall (\(b\)), filling a wetland (\(c\)), and high winds (\(d\)) are density - independent factors as they do not depend on the size of the yellow warbler population.

Answer:

B. limited water, F. limited rainfall

2.