Deck 16: Populations, Communities, and Change

Question 1

Imagine an ecosystem rich in panda's. What are the factors that might limit the population growth of these cuddly animals? Identify the source of these limitations; i.e., the hydrosphere, atmosphere, biosphere, anthroposphere, or a combination of spheres.

Answer 1

There are several factors that could limit the population growth of pandas in their ecosystem. One factor could be the availability of their primary food source, bamboo. If there is a shortage of bamboo due to environmental factors or human activities such as deforestation, it could limit the pandas' ability to find enough food to support a growing population. This limitation would be sourced from the biosphere, as it directly impacts the availability of resources within the pandas' natural habitat.

Another factor could be the loss of habitat due to human encroachment and development. This could lead to a reduction in the available space for pandas to live and reproduce, ultimately limiting their population growth. This limitation would be sourced from the anthroposphere, as it is driven by human activities and their impact on the pandas' environment.

Additionally, changes in the climate and weather patterns, sourced from the atmosphere and hydrosphere, could also impact the pandas' ability to thrive and reproduce. For example, extreme weather events or shifts in temperature and rainfall patterns could disrupt their natural behaviors and negatively affect their population growth.

Overall, the limitations on the population growth of pandas could be sourced from a combination of the biosphere, anthroposphere, atmosphere, and hydrosphere, as they are all interconnected and can impact the pandas' ecosystem in different ways.

Question 2

Allopatric speciation can occur when part of a population becomes geographically isolated. Causes of geographic isolation could be a river or a lava flow. What other ways can part of a population become separated or isolated from the rest?

Answer 2

Other ways a population can become separated or isolated from the rest include:

1. Mountain Ranges: The formation of new mountain ranges can separate populations, preventing them from interbreeding.

2. Oceans and Seas: The rise of sea levels can create islands, isolating populations. Similarly, populations can be separated by large bodies of water.

3. Glaciation: During ice ages, glaciation can isolate populations.

4. Human Activity: Construction of roads, cities, dams, and other human-made structures can create barriers that separate populations.

5. Climate Change: Changes in climate can create new habitats or destroy existing ones, leading to the isolation of populations.

6. Dispersal: Some species may disperse or migrate to new areas, leading to isolation.

7. Plate Tectonics: The movement of Earth's crust can lead to the formation of new landforms, separating populations.

8. Changes in Habitat: Changes in the availability of food, predators, or other environmental factors can lead to the isolation of populations.

9. Biological Factors: Differences in mating seasons or behaviors can lead to reproductive isolation, even without physical separation.

10. Wind and Water Currents: These can carry organisms to new locations, leading to geographic isolation.

Each of these factors can lead to allopatric speciation, as they prevent gene flow between the separated populations. Over time, the populations may evolve different traits and become distinct species.

Question 3

A __________ is a group of individuals of the same species, which interbreed and share genetic information.

Answer 3

population

Question 4

The change in the number of individuals in a population over time is called its __________ rate.

Question 5

As the population ___________ , or number of individuals per unit area increases, the environment becomes more crowded.

Question 6

A ___________ is a group of interacting, interdependent organisms of different species that share the same environment.

Question 7

The __________ rate in a population represents the individuals that have died during a certain period of time.

Question 8

A relationship in which one partner benefits while the other is harmed is called __________.

Question 9

___________ refers to relationships that are beneficial to both of the interacting organisms.

Question 10

The physical environment in which a population or an organism lives or could live is its __________.

Question 11

Another way to think about competition for resources within a given habitat is to consider the competitive __________ principle, which states that two species that have exactly the same requirements cannot coexist in exactly the same habitat or niche.

Question 12

__________ are species that have a wide range of tolerance that occupy large, broadly defined niches.

Question 13

When a new species arises through complete geographic isolation, it is called __________ speciation.

Question 14

High __________ makes communities more resilient, more able to adapt to change, and more likely to withstand major environmental upheavals.

Question 15

__________ diversity refers to the variety of habitat types available in an ecosystem.

Question 16

A species in imminent danger of extinction is called an ___________ species.

Question 17

A species that has shown a significant decrease in population or range is a __________ species.

Question 18

Genetic __________ refers to the variability or heterogeneity that is available among the DNA of individuals within a population or species.

Question 19

Environments such as zoos, aquaria, and botanical gardens are examples of __________ ecosystems.

Question 20

Since 1990, over __________ new species of mammals have been identified and named.

Question 21

A community is a group of individuals of the same species that interbreed and share genetic information.

Question 22

A typical biological population will grow until it is limited by environmental factors.

Question 23

Factors that limit or control population growth in the real world include limitations to food.

Question 24

If the population undershoots the carrying capacity, deaths will exceed births and the population will decline.

Question 25

K-strategists tend to be smaller with shorter life spans and early maturity.

Question 26

Interactions between individuals in communities have no influence on populations and on ecosystems as a whole.

Question 27

In competition, individuals vie for scarce resources.

Question 28

Carnivores eat only plants, herbivores eat only animals, and omnivores eat both.

Question 29

A mutualistic relationship is beneficial to both interacting organisms.

Question 30

A keystone species plays a minimal role in an ecosystem.

Question 31

The physical environment in which a population or an organism lives or could live is its habitat.

Question 32

The greater the complexity of the environment, the less niche opportunities there may be, and the less opportunity for organisms to specialize.

Question 33

Generalists have a wide range of tolerance and occupy large, broadly defined niches.

Question 34

In the case of sympatric speciation, reproductive isolation and speciation may take place as a result of behavioral specialization and differentiation.

Question 35

If genetic diversity is too limited, a species population will be less adaptable to environmental change.

Question 36

Scientists presently know the exact number of species on Earth, and new species are being discovered all the time.

Question 37

Human activity does not damage ecosystems and does not endanger biodiversity.

Question 38

When the natural population of an endangered species drops too low, it may require ex situ conservation, such as in a zoo or aquarium.

Question 39

Utilitarian arguments for the value of biodiversity are based on the usefulness of a species to humans.

Question 40

A tube worm is a creature that lives within the dark, hot, and mineral-rich conditions of a hydrothermal vent. Deep-sea bacteria use chemosynthesis to convert energy into a chemical form. Of the follow, which is the most likely way that a tubeworm living in a hydrothermal vent environment acquires its energy?

A) Mutualism with hydrothermal vent bacteria.
B) Commensalism with hydrothermal vent bacteria.
C) Parasitism with hydrothermal vent bacteria.

Question 41

The death of the dinosaurs opened up the door for what species to dominate (and fill in the newly empty niche)?

A) Fish.
B) Mammals.
C) Reptiles.
D) Birds.

Question 42

Which of the following is not a result of high population density?

A) Mortality will increase.
B) There will be waste accumulation.
C) Predators will ignore prey that is abundant.
D) None of these.

Question 43

A community plus the nonliving factors and variables which it interacts with is called a(n)

A) Biome.
B) Ecosystem.
C) Population.
D) Community.

Question 44

Which of the following populations is most like to go extinct?

A) Small population in a stable environment.
B) Large population with large amounts of genetic variability.
C) Moderate-sized population with large amounts of genetic variability.
D) Small population in an unstable environment.

Question 45

is the number of individuals per unit area.

A) "Niche".
B) "Population density".
C) "Distribution".
D) "Mortality".

Question 46

In the mathematical equation that describes exponential growth (dN/dt = rN), what does the N stand for?

A) Unit of time.
B) Number of individuals.
C) Growth rate.
D) None of these.

Question 47

What occurs during exponential growth?

A) The number of individuals in a population increases rapidly.
B) The number of individuals in a population decreases rapidly.
C) The number of individuals in a population increases slowly.
D) The number of individuals in a population fluctuates.

Question 48

The realized niche of an organism is

A) The life pattern that the organism would like to assume, but cannot.
B) The life pattern that the organism actually assumes. The fundamental niche is a subset of the realized niche.
C) The idealized niche of nature rather than the actual niche of nature.
D) The life pattern that the organism actually assumes. It is a subset of the fundamental niche.

Question 49

The number of species in a community is

A) Speciation.
B) Species diversity.
C) Species evenness.
D) Species richness.

Question 50

With which of the following is "character displacement" associated?

A) Allopatric species.
B) Sympatric species.
C) Species richness.
D) Species diversity.

Question 51

What is the evolution of two interacting species in a community?

A) Allopatric speciation.
B) Coevolution.
C) Sympatric speciation.
D) Species diversity.

Question 52

Removal of which of the following from a community will have the greatest effect to the community structure?

A) Predator.
B) Competitor.
C) Keystone species.
D) None of these. They are all equally important to the community structure.

Question 53

Of the following types of interactions, which one is most likely to limit population size?

A) Parasitism.
B) Commensalism.
C) Competition.
D) Predation.

Question 54

will result when two or more organisms attempt to utilize the same resource.

A) Mutualism.
B) Commensalism.
C) Competition.
D) Parasitism.

Question 55

The lack of allele variation in the Northern elephant seal population is an example of

A) Niche differentiation.
B) Genetic diversity.
C) Habitat diversity.
D) The bottleneck effect.

Question 56

Biodiversity is basically a measure of

A) The amount of non-living entities within an ecosystem.
B) The variety of species within an ecosystem.
C) The amount of shared resources within an ecosystem.
D) The variety of insects within an ecosystem.

Question 57

An animal that eats only plants is a(n)

A) Carnivore.
B) Herbivore.
C) Omnivore.

Question 58

Which of the following terms defines the following: Two organisms try to get the same thing.

A) Niche.
B) Mutualism.
C) Parasitism.
D) Habitat.
E) Competition.

Question 59

Which of the following terms defines the following: Two organisms benefit in a relationship.

A) Niche.
B) Competition.
C) Parasitism.
D) Habitat.
E) Mutualism.

Question 60

Which of the following terms defines the following: The role a species fills within a habitat.

A) Niche.
B) Mutualism.
C) Competition.
D) Parasitism.
E) Habitat.

Question 61

When members of a population move out of a given area, it is called

A) Immigration.
B) Emigration.
C) Death rate.
D) Birth rate.

Question 62

Approximately how much of the world is protected by international agreement?

A) 0.02 percent.
B) 10 percent.
C) 15 percent.
D) 2 percent.

Question 63

How many total condors are known to be left in the world?

A) 18
B) 10,003
C) 384
D) 24

Question 64

Which island fragment will support the lowest number of species?

A) Small and isolated.
B) Large and close to the mainland.
C) Small and close to the mainland.
D) Large and isolated.

Question 65

According to the Species-Area Relationship graph, if there is a location that has an area of about 30 square meters, what is the total number of species it can approximately support?

A) 5 species.
B) 50 species.
C) 25 species.
D) 10 species.

Question 66

The number of mosquito genera varies as a function of what variable?

A) Altitude.
B) Latitude.
C) Continental versus coastal.
D) None of these.

Question 67

What occurs in peripatric and parapatric speciation?

A) Part of the population colonizes an adjacent but slightly different habitat.
B) A portion of the population becomes reproductively isolated as a result of a geographic barrier.
C) Part of the population migrates away, never to return.
D) Part of the population dies, providing more nutrients for the remaining population.

Question 68

Due to the eastern gray squirrel being introduced into the British Isles, the British red squirrel population is

A) Growing.
B) Declining.
C) Staying the same.

Question 69

Which of the below is generally a safer strategy for survival?

A) Generalist.
B) Specialist.

Question 70

If there are variations in environmental conditions, what can happen when niches of species overlap?

A) The niche can split.
B) One species will definitely dominate the niche.
C) One species will get eaten by the other.
D) One species will demise rapidly.

Question 71

Calculate the growth rate (r) based on the following data: Population at end of period equals 1,000; Population at beginning of period equals 100.

A) 0.9 during the period.
B) 900 during the period.
C) 9,000 during the period.
D) 9 during the period.

Question 72

From the list below, which is a benefit of wetlands to the environment?

A) Protect shorelines from storms.
B) Cleansing of toxins from soils and water.
C) Provides an enormous storage reserve for carbon.
D) Pollination of many crops.

Question 73

When will the growth rate of a natural population equal zero? Note: N = population at the end of a period - population at the beginning of a period; K = carry capacity.

A) When N/K equals 0.
B) When N/K equals 1.
C) When N is much greater than K.
D) When birth is greater than death.