Question 1

The definition of an area,relative to a population study,

Accepted Answer

The definition of an area relative to a population study depends on the questions being asked and specific characteristics of the species forming the population. For example, the area for a study on a small bird species may be smaller than the area for a study on a large mammal species. It may also vary depending on the habitat type and distribution of the species within it. Therefore, it is not constant or always a fixed measurement like 1 square meter, and it is not based on whether the area is terrestrial or aquatic.

Question 2

The decrease in the availability of food,access to water,or access to cover that accompanies increasing population size illustrates the concept of a(n)

Accepted Answer

Density-dependent factors are those that become more intense or significant as population density increases, such as competition for resources (like food and water) and increased exposure to diseases. The decrease in availability of food, access to water or cover is an example of density-dependent factor because as the population increases, more individuals will be competing for the same resources, which will become less available.

Question 3

Which of the following is likely to make the smallest contribution to annual changes in the size of a population?

Accepted Answer

Global climate change may have long-term effects on a population, but on an annual basis, its impact is likely to be smaller than the other options listed. Extreme weather events, introduced predator species, and disease outbreaks can have more immediate and direct effects on population size.

Question 4

The change in size of a given population of organisms may have a direct impact on humans.The 1993 outbreak of hantavirus in the southwestern United States was partly due to a(n)

Accepted Answer

The increase in the deer mouse population size would have provided more opportunities for human exposure to hantavirus, as this species is a known host for the virus. The other options are less likely to have directly caused the hantavirus outbreak.

Question 5

A population is counted at 100 individuals in 1998.In 2006,a new count found 1,600 individuals.What is the doubling time for the population?

Accepted Answer

To calculate the doubling time, we can use the formula:
doubling time = (time taken for population to double * log2)

Let's start by finding out the growth rate of the population:
growth rate = (final population/initial population)^(1/time) - 1
growth rate = (1600/100)^(1/8) - 1
growth rate = 1.405 - 1
growth rate = 0.405 or 40.5%

Now we can use the formula for doubling time:
doubling time = (ln2/growth rate)
doubling time = (0.693/0.405)
doubling time = 1.71 years or approximately 2 years (rounded to the nearest year)

Therefore, the answer is D) 2 years.

Question 6

Nene,the Hawaiian goose,live in the wild on Hawaii,Maui,Kauai,and Molokai.The population density on Maui is 0.227 birds per square kilometer,and the island is 1,830 square kilometers in size.Approximately how many nene live on Maui?

Accepted Answer

To find the number of nene on Maui, we can multiply the population density by the size of the island:
0.227 birds per square kilometer * 1,830 square kilometers = 415 nene

Therefore, the best choice is C) 415.

Question 7

A population of 100 individuals has a doubling time of 25 years.What size will this population be in 100 years?

Accepted Answer

The population will double every 25 years, so in 100 years, it will double 4 times. 100 x 2^4 = 1,600.

Question 8

Which of the following has the highest population density?

Accepted Answer

Population density is calculated by dividing the number of individuals by the area they occupy. Therefore, the highest population density is seen in 1,500 oysters living in an area of 1,500 square meters.

Question 9

Which of the following populations would be most vulnerable to an outbreak of a communicable disease?

Accepted Answer

The population of 250,000 people living in an area of 100,000 square meters would be most vulnerable to an outbreak of a communicable disease due to the high population density, making it easier for the disease to spread quickly among individuals.

Question 10

Which density-dependent process contributed most significantly to the recovery of the North American monarch butterfly population after the severe winter losses of 2002?

Accepted Answer

Density-dependent factors such as competition for resources and disease can limit population growth, but in the case of monarch butterflies, egg production is inversely proportional to density. With ample resources, the surviving monarchs were able to maximize their reproduction, leading to a significant population recovery. Mild weather and reduced predation may have also played a role, but egg production is likely the most significant factor.

Question 11

The term population density describes the

Accepted Answer

Population density refers to the number of individuals of a particular species present per unit area. It is a measure of the abundance of a species in a given area. Therefore, the correct choice is B, which states the number of individuals per unit area. Choice A refers to body size, choice C refers to the number of different populations in an area, and choice D refers to the number of species in an area, none of which are measures of population density.

Question 12

Which of the following choices best explains why some introduced species experience an initial period of exponential growth?

Accepted Answer

Introduced species often experience exponential growth because they lack natural predators and/or parasites in their new habitat. This allows them to grow quickly until a critical resource becomes limiting, at which point their growth rate slows down.

Question 13

The size of a population can be decreased by

Accepted Answer

Emigration is the movement of individuals out of a population and can lead to a decrease in population size. Higher birth rates and reduced death rates will lead to an increase in population size, while immigration will also increase the size of the population.

Question 14

A population will remain at a constant size when emigration equals immigration and

Accepted Answer

A constant population size requires that the number of individuals leaving the population is equal to the number of individuals entering the population. Therefore, emigration equaling immigration is necessary, but not sufficient. Additionally, births must equal deaths in order to maintain a constant population size. The other choices - food availability, predator presence, and available space - may affect population growth or decline, but are not necessary for a population to remain at a constant size.

Question 15

A population of 100 individuals is undergoing exponential growth,with a constant growth rate of 0.2 per year.What size will this population be in 2 years?

Accepted Answer

We can use the formula for exponential growth to find the size of the population after 2 years:
N = N₀e^(rt)
where:
N₀ = initial population = 100
r = growth rate = 0.2
t = time period = 2 years
e = Euler's number (approximately 2.718)

Plugging in the values, we get:
N = 100e^(0.2*2)
N = 100e^0.4
N ≈ 144.2

Therefore, the size of the population after 2 years is approximately 144, which corresponds to choice C).

Question 16

Which of the following populations would be most likely to experience an S-shaped growth pattern?

Accepted Answer

A wolf population that has been reintroduced to an area where they once lived but were locally extinct will initially have a slow population growth due to small population size and limited resources. As the population increases, competition for resources will increase, leading to a slowing growth rate and eventually a stable population size, forming an S-shaped growth curve.

Question 17

The population explosion that occurred shortly after the Opuntia cactus was introduced to Australia is an example of

Accepted Answer

The term "population explosion" signifies exponential growth, which refers to a rapid increase in the size of a population due to the availability of abundant resources. The introduction of the Opuntia cactus in Australia provided a new food source for herbivores, which led to an increase in their population numbers. As a result, the predator population also increased, leading to a further surge in the herbivore population. This cycle of growth continued until the available resources could no longer sustain the population, resulting in a drastic decrease in their numbers.

Question 18

A new species is introduced into a given area.The population size begins to grow slowly,then at a very rapid rate,and finally levels off at a stable number.This growth pattern is best represented by a(n)

Accepted Answer

The growth pattern described is typical of an S-shaped population curve, where the population grows slowly at first, experiences exponential growth, and then levels off as it reaches the carrying capacity of the environment. The other options do not accurately describe this type of growth pattern.

Question 19

The maximum population size that can be supported by its habitat is known as

Accepted Answer

Carrying capacity is the maximum number of individuals that an environment can sustainably support. Option A (maximum increase) refers to the highest rate of population growth, option C (exponential growth) refers to a rapid increase in population size, and option D (population balance) is not a commonly used term in ecology.

Question 20

A flock of geese (Flock A)has 100 individuals and an annual growth rate,r,of 1.5.Another flock (Flock B)has 200 individuals and an r of .7.Flock C has a population of 75 and an r of 2.Flock D has a population of 50 and an r of 4.Assuming no other factors are involved,which herd will be largest next year?

Accepted Answer

Flock D has the highest annual growth rate, which means their population will increase at the greatest rate compared to the other flocks. Even though their initial population is smaller than Flocks A and B, their rate of growth will allow them to surpass the other flocks in size next year.

Quiz 21: Growth of Populations