1. Many
species of birds form large flocks. What dispersion pattern describes this
behavior? Clumped.
2. Organisms
that produce all of their offspring in a single event are semelparous.
3. In
the graph below, the top line (with the triangles) represents the fastest
growth rate of the three curves.
4. K-selected
populations tend to reproduce quickly. False
5. Dispersion
is the spatial distribution of individuals.
6. Random
dispersion is rare compared to clumped dispersion. True
7. Changes
that occurred in the growth of the iguana population over time.
·
In the first few years on their new
island, an iguana population had abundant food supplies, allowing all
individuals to survive and reproduce.
·
Due to the unlimited resources, the
population grew exponentially.
·
As generations went by, however, the
population’s growth rate slowed down because food supplies became more limited.
·
Females that were poorer competitors
produced lower-quality eggs, many of which never hatched. The population
reached its carrying capacity, and the growth rate decreased to zero.
·
As the population grew in size and
resources became limited, the population grew logistically.
8. What
is true of exponential growth?
·
It can be seen in nature when a
population arrives in a new area without natural enemies.
·
A population’s resources must be
unlimited for it to occur
9. For
each of the following, indicate the idealized survivorship curve being
described.
·
Type 1 survivorship curve
(a) Asian
elephants, which exhibit the highest death rate late in life
(b) Primate
species that have few offspring and high levels of parental care
·
Type 2 survivorship curve
(a) A
songbird species for which the chance of death is approximately equal
throughout its lifespan
·
Type 3 survivorship curve
(a) A plant species for which the majority of
seedlings do not survive more than a few days
(b) A frog species that lays massive numbers of
eggs in the water, most of which will not survive to sexual maturity
10. What
factors are examined by the field of demography?
·
Birth and death rates in a population; Population
size; Distribution of ages in a population
11. A
survivorship curve with uniform death rates over time is most likely to be a
type 2 curve.
12. Based
on the demographic transition model, where and when would you expect the see
the highest rate of population increase? Mexico; 1925-1975
13. A
survivorship curve in which most individuals die late in life is a type 1
curve.
14. Worldwide
human population growth has been exponential since the Industrial Revolution.
true
15. You
are inspired by your professor's lecture on human demography to decrease your
ecological footprint. What steps would help you accomplish this goal?
·
Carpool, walk, and bike more often; Eat
at least one meat-free meal per day
16. Life
history strategies differ along a continuum from what is referred to as
“r-selected species” to “K-selected species”.
·
r-selected
¨ high
annual per capita population growth
¨ poor
competitive ability
¨ large
number of offspring produced at one time
¨ reproductive
age reached early
¨ short
life-span
·
K-selected
¨ Stable
population size at or near carrying capacity
¨ Long
life-span
¨ Outcompetes
other species for resources
17. A
mark-recapture program marked 10 individuals in the first catch. The second catch
has a total of 8 individuals, 4 of which were recaptures. What is the estimate
of total population size? 20
18. Exponential
growth is rare because resources are usually limiting. true
19. A
plot of population size vs time that displays a J-shape is indicative of
exponential growth.
20. A
fisheries biologist tells you she is studying a cohort of salmon returning to
their birth river. What does this tell you about these salmon? They are the
same age.
21. A
population would be most likely to likely have a low growth rate under what
condition? At or near carrying capacity.
22. Lions,
leopards and other large terrestrial predators that maintain well-defined
territories. What kind of dispersion pattern would this produce? Uniform.
23. Setting
their offspring adrift is a very important survival mechanism for invertebrate
coastal species because it allows the offspring to populate new areas. True
24. Offspring
drifting away from their parents provides no genetic benefit to the species
that practice this method of parenting. False
25. A
scientist studying a particular species of microorganism in the plankton finds
that its distance from the water’s surface changes in response to changing
light levels, water clarity, and plankton density. Which of the following is
the most likely reason the microorganism changes its depth? It is photosynthetic and must insure
that it gets enough light.
26. Most
organisms that practice the method of parenting shown in the video produce
large numbers of offspring each breeding cycle. What is the most likely reason
that these organisms produce such large numbers of offspring? Predation of the
offspring of these organisms is extremely high.
27. If
the water column did not promote the dispersal of the plankton to new areas,
what are the possible outcomes of this event?
§ Increased
competition among related individuals
§ Loss
of diversity among the populations due to inbreeding
28. Drought
and floods are considered to be density-dependent factors potentially affecting
population size. False
29. Complete
the sentences with the appropriate words to explain the concept of an
ecological footprint.
§ An
individual’s ecological footprint is the total amount of productive land needed
for survival in a sustainable manner.
§ The
primary demands contributing to the ecological footprint in developed countries
are for energy (electricity and gas) and then food.
§ In
addition to using more energy to power their cars and light their homes,
developed countries also tend to eat more meat, which requires more land to
produce than does the production of plants.
§ Globally,
humans have exceeded the Earth’s carrying capacity because some populations are
living in an unsustainable manner, using up resources that are not renewable.
30. Classify
each situation as a density dependent, inverse density dependent, or density
independent mortality factor.
§ Density
dependent
·
As a heron population grows, competition
for food and nesting sites reduces offspring survival
·
Death rates from avian malaria decline a
tropical bird species lose habitat
§ Inverse
density dependent
·
A jaguar kills 4 antelope per week,
regardless of the size of the antelope herd
§ Density
independent
·
A forest fire kills 80% of the lodgepole
pine trees found in a state park
·
An unusual cold spell in April resutis
in very high mortality for Florida manatees
31. r-selected
species tend to have type III survivorship curves. True
32. In
a growing population, the youngest age classes have the most individuals.
33. The
ecological footprint of an average Egyptian is greater than that of an average
American. False
34. If
the age structure of a country's population is balanced, what prediction can be
made about the near future? The
population will not increase rapidly.
35. A
group of interbreeding individuals occupying the same habitat at the same time
is a(n) population.
36. Humans
are iteroparous. False
37. Indicate
if the following statements are true or false concerning human population
growth.
§ High
birth rates were offset by high death rates due to wars, famines, and epidemics
prior to 1750. True
§ Women
marrying later in life tend to reduce the birth rate in a population. True
§ The
birth and death rates, while changing over the years, have been fairly
consistent across populations within a given time period, even comparing
developed vs. developing countries. False
§ Improvements
in public health decreased the overall death rates in populations. True
§ Human
global population growth is beginning to level off as it has now hit the
Earth’s carrying capacity. False
§ As
total fertility rates go down, the birth rates in all countries will decrease,
regardless of the age structure of the population. False
§ The
total fertility rate varies between regions, and in most regions has decreased
over the last 30 years. True
§ If
the average fertility rate globally drops to around 2.0, the global human
population size will begin decreasing. False
38. The
difference between the two lines on the graph below is the carrying capacity.
39. Modern
humans show a type I survivorship curve. True
40. Select
all of the following that are true of the intrinsic rate of population growth.
§ It
is the rate of population growth under optimal conditions
§ It
is not often seen in nature
§ It
is most commonly seen in new, expanding populations.
41. Organisms
that reproduce repeatedly are said to be iteroparous.
42. You
are studying a population of plants that need ample rainfall and soil nitrogen
to reach maturity. Reproduction in mature plants is dependent upon having high
densities of pollinators in the area. Your experiment involves providing
supplemental water and nitrogen-containing fertilizer to the plants for several
years. Do you think these two steps will increase the carrying capacity of the
population? No, because even if more plants reach maturity, the number of
pollinators will still be a limiting resource.
43. Parasitism
usually affects populations in a density-dependent manner.
44. Why
is a random dispersal pattern quite rare in nature? Because resources in nature
are rarely randomly spaced.
45. Indicate
the pattern of dispersion that is being described.
§ Uniform
spacing
·
A mature stand of pine trees in
competition for water and space
·
A species of lizards in which males
defend territories of roughly the same size
§ Random
spacing
·
Seedlings of a wind-dispersed plant on a
fertile forest floor
§ Clumped
spacing
·
A group of surgeon fish that remain
together as they forage on a reef
·
A high density of Sycamore trees growing
along a stream bank
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