Biology - Chapter 56 - Connect
Which of the following would be the most likely method used by ecologists to determine density of clonal individuals?
Estimating the amount of ground covered by clonal plants.
The mist net technique would be a good way to find out how many:
bats live in a cave
Clumped dispersion is the most common dispersion pattern in nature:
because resources tend to be aggregated into one area
A mark-recapture study would be a good way to find out how many:
fish live in a lake
In a life table, nx refers to the number of individuals alive at the start of the year, where n is the ____ and x is the particular ___ ___
number; age class
Visual counts of organisms is a good way to estimate population density of:
relatively large organisms in small areas.
The number of offspring born to all females of all ages represents:
the overall growth rate per generation
In a ____ dispersion pattern, organisms are distributed with about equal distance between them across the landscape
uniform
An ecologist would estimate population density by:
using sampling techniques
Which of the following best illustrates a population?
A group of antelope jackrabbits found inhabiting south-central Arizona
What is a population?
A group of individuals of the same species interacting with each other in the same area
____ dispersion occurs when individuals are found in clusters and the clusters are often separated by some distance.
Clumped
What type of dispersion pattern results from uneven or clustered distribution of resources?
Clumped dispersion
True or false: A population is a fluid entity with individuals migrating in and out of an area
True
To measure the population of lake trout in a 1000 hectare lake, 100 individuals were netted and marked with a fin clip, and then returned to the lake. The next week, the lake was netted again, and out of the 100 lake trout that were caught, 10 had fin clips. Using the capture-recapture estimate, the lake trout population size would be closest to which of the following?
1,000 (b/c: Total population size, N = Number of marked individuals in 1st catch x total # of 2nd catch / # of marked recaptures in 2nd catch) So, N = 100*100/10 = 10,000/10 = 1,000, the answer is 1,000
A population ecologist is sampling a population of spiders. She is using a quadrat that measures 50 cm x 50 cm and encloses an area of 0.25 m2. She counted densities of 30, 46, 27, and 9 individuals in four different quadrats. The average density of this species of spiders is
28
o measure the population density of monarch butterflies in a park, 100 butterflies were captured, marked with a small dot on a wing, and then released. The next day, another 100 butterflies were captured, including 20 recaptured marked butterflies. Based on these data, the population size is approximately:
500
Which of the following organisms are semelparous?
Agave and Salmon
Which of the following would be used by an ecologist to estimate the density of a population?
An ecologist would use mark-recapture techniques.
What type of dispersion pattern involves individuals found in groups that are often found some distance from one another?
Clumped
Demography is the study of which of the following?
Birth and death rates, age distribution, and population sizes
How can clonal vegetation density be estimated?
By measuring the amount of ground covered by clonal plants
Which of the following definitions is the best description of clonal organisms?
Clonal organisms are patches of genetically identical individuals
Which of the following statements correctly defines Murie's hypothesis about the Dall mountain sheep in Denali National Park?
Controlling the wolf population would protect reproductively active sheep.
Which of the following statements is the correct definition of demography?
Demography is the study of the vital statistics of populations and how they change over time.
Use the quadrat method to estimate plant density given the following information: quadrat sample 1 has 65 plants, quadrat sample 2 has 40, quadrat sample 3 has 85, and quadrat sample 4 has 30. Assume the quadrat measures 50 cm x 50 cm and encloses an area of 0.25 m2.
Density is 220 individuals per m2
Use the quadrat method to estimate plant density given the following information: quadrat sample 1 has 65 plants, quadrat sample 2 has 40, quadrat sample 3 has 85, and quadrat sample 4 has 30. Assume the quadrat measures 50 cm x 50 cm and encloses an area of 0.25 m2:
Density is 220 individuals per m^2
What is density in terms of populations?
Density is the numbers of organisms in a given unit of area or volume.
_____ refers to the spatial distribution of organisms within a populations
Dispersion
Which of the following best exemplifies the use of line transect to determine population density?
Stretching a long line through a forest, counting all the individuals of a species found within a certain distance of that line.
Which of the following factors contribute to clumped spacing patterns?
Flocking or herding behaviors; Uneven distribution of resources
Which of the following describes the mark-recapture technique for determining density?
It is the marking, releasing, and re-sampling of the population to determine the number of marked versus unmarked individuals.
Which of the following methods are most often employed by ecologists to estimate density of plants?
Line transects; quadrats
The capture-recapture method can be used to estimate estimate population size, but only after making these assumptions. Choose all that apply:
Marked individuals mix thoroughly with the rest of the population after being marked Marked and unmarked individuals have the same probability of being trapped During the course of the estimate, no individuals have entered or left the population.
Which of the following assumptions are usually made by ecologists when using the mark-recapture technique to estimate density?
No births or deaths have occurred in the population; No immigration or emigration has occurred within the population
Which of the following accurately summarize how predation can act as a density dependent factor in a population?
Predators may kill a larger proportion of prey when the prey is common.
____ and ___ ___ are two common sampling methods used by plant ecologists to determine vegetation density
Quadrat; line transect
Correctly pair the species with the sampling method used to determine population density: Quadrats = Pitfall traps = Mist nets = Baited live traps =
Quadrats = Plants Pitfall traps = Beetles Mist nets = Birds Baited live traps = Lion Tamarin
What dispersion pattern is the rarest and may result when resources are common and abundant?
Random dispersion
Why is clumped dispersion the most common dispersion pattern observed in nature?
Resources in nature tend to be clustered
______ is a reproductive strategy in which organisms reproduce during one single even, whereas, ______ is a reproductive strategy in which organisms reproduce throughout their lifetime.
Semelparity; iteroparity
Which of the following statements about semelparity are correct?
Semelparous organisms invest most of their energy in reproduction; Semelparous organisms have a single reproductive event in their lifetime; Semelparity is favored in a stable environment
Which of the following sampling methods is the most effective method used by ecologists to estimate the density of large plants?
The line transect method
What is population ecology?
The study of how populations grow and what factors promote and limit population growth.
Which of the following describes the function of radio-collars and telemetry for population ecologists?
They can be used to determine home ranges large animals and based on area of available habitat estimate density They can be used to determine dispersion patterns based on home ranges of large animals
Which of the following techniques uses string stretched between two points, and any organism along its length is counted for estimating density?
Transect lines
Which of the following include methods used by population ecologists to estimate density?
Trapping animals in a small area; Capturing animals, tagging and then releasing them
Murie's data are organized in the form of a life table, and a survivorship curve is constructed as shown in the graph. What type of survivorship is depicted in the graph?
Type I (because they were of older age and were being eaten- not Type II or Type III, because they are not being eaten at young ages)
A female preying mantis lays several hundred eggs in a foam mass in the fall. The young are most vulnerable when they emerge in the spring, but the few that survive spread out over the countryside and, if they find a mate, lay eggs the following fall. What type of survivorship curve is this?
Type III
A spacing pattern where the organisms are spaced at about equal distance throughout the landscape is called which of the following?
Uniform
Which of the following methods would most accurately measure the population density of a large tree species on a large island?
Using the line transect method, count all the trees of a given species within 1 m on either side of the transect
Select all of the following that are the drawbacks of the mark-recapture technique:
When animals become trap-happy, the population size is underestimated When animals learn to avoid the traps, the population size overestimated
How can predation act as a density-dependent factor in a population?
When prey are rare, predators ignore the prey and kill few individuals.
Use the mark-capture equation to estimate population size given the following information: You caught 50 blue jays and marked them. One week later you caught 100 blue jays and 10 were marked.
You estimate population size to be 500 blue jays
In commercial fisheries the relative population density of fishes in an area of the ocean is estimated:
by examining catch per unit effort
In order to estimate population density over a large area, population ecologists:
calculate density of organisms in a small area and use this number to estimate total abundance over a large area.
Which of the following would be a common and valuable tool for population ecologists working in the commercial fisheries industry?
catch per unit effort
Organisms that grow in patches of genetically identical individuals are called:
clonal
Which of the following dispersion patterns is the most common pattern observed in nature?
clumped
Which of the following are the three types of dispersion patterns?
clumped, random, uniform
The three types of dispersion patterns are:
clumped, uniform, and random
Select all of the following that would result in random spacing patterns within a population:
common and abundant resources; moist fertile soil
Uniform dispersion often results from:
competition for resources among individuals
Population ___ is the number of organisms in a given unit area or volume
density
When making decisions about species management:
ecologists must gather knowledge of both population growth and population density
A population is a:
fluid entity composed of individuals that migrate into and out of the given area
A quadrat is used to count the number of individuals ____, and a line transect is used to count the number of individuals ____.
found within a square plot; within a specific unit of measurement along a long piece of string
Organisms living in unpredictable environments that are unstable, with unpredictable juvenile survival rates would favor ___ as their reproductive strategy.
iteroparity
Murie's hypothesis about the Dall mountain sheep in Denali Nation Park was that:
limiting the wolf population would protect reproductively active adult sheep in the population
A ____ ____ is a sampling technique in which a string is stretched along the ground in a straight line between two poles and any organism along its length is counted.
line transect
To estimate the density of large plants, the most effective sampling method is the ___ ____ technique
line transect
The ____ _____ technique is a sampling method in which animals are captured, tagged, released, and recaptured to estimate population density
mark-recapture
The ratio of marked to unmarked individuals in the second sample is the same as the ratio of marked individuals in the first sample to total population size. This is one assumption that has to be made by ecologists using the
mark-recapture method
The leg tag on this bird is a key element of the ___ ____ ____ used to estimate population size
mark-recapture technique
A group of individuals of the same species occupying the same area at the same time is called a(n):
population
A pond represents an ecosystem, whereas a species of fish in the pond represent a(n):
population
In sexually-reproducing species, a(n) ____ can be defined as a group of interbreeding individuals of the same species occupying the same area at the same time.
population
For animals with valuable pelts, ecologists can use pelt records from trading stations to determine ____ over time.
population densities
The study of factors affecting population size and how these factors change over space and time is called:
population ecology
To make more precise decisions about species management, ecologists particularly need to collect data on:
population growth and population density
A square frame used to enclose an area in order to isolate a sample and determine population density is called a:
quadrat
Plant ecologists employ a sampling device called a(n) ___. It consists of a square frame which can be used to outline an area for population density estimates.
quadrat
When estimating population density an ecologist may use a(n) __, which is a square plot of land of an enclosed area to isolate a species, or a(n) ___ ____, which is a tape laid out in a straight line along two poles.
quadrat; line transect
When individuals are arbitrarily spaced within a population and resources are abundant and common, the dispersion pattern is said to be
random
When individuals are arbitrarily spaced within a population and resources are abundant and common, the dispersion pattern is said to be:
random
Common and abundant resources, as in moist, fertile soil can lead to:
random dispersion
The rarest dispersion pattern found in nature is ___ ____
random spacing
The population growth rate per generation is the net ______ rate.
reproductive
Why is clumped dispersion the most common dispersion pattern observed in nature?
resources in nature tend to be clustered
A reproductive strategy in which the organism produces all their offspring in a single reproductive event is called:
semelparity
K-selected species exhibit ______, whereas r-selected exhibit ______ (choose all that apply).
slow development, good competitive abilities; rapid development, poor competitive abilities low mortality rates of young, low reproductive rates; high mortality rates of young, high reproductive rates
Scientists using the mark-recapture technique assume that the ratio of marked to unmarked individuals in the second sample is:
the same as the ratio of marked individuals to total population size in the first sample
Dispersion patterns are:
the spatial arrangement of organisms within a population
The simplest method used to estimate population density of a relatively large species in a small area is __________________________
to visually count the number of organisms
The simplest method used to estimate population density of a relatively large species in a small area is:
to visually count the number of organisms
When estimating population density by the mark-recapture method, trap-happy animals result in an ______ whereas trap-shy animals result in an _______ of population size:
underestimate; overestimate
