Module 8 Populations and Communities Flashcards
Density can have effects on interactions within a population such as competition for food and the ability of individuals to find a mate.
true
Mark and recapture is a method used to determine population size in mobile organisms.
true
Life tables were initially developed by life insurance companies to set insurance rates.
true
Death rate is the number of deaths within a population at a specific point in time.
true
Population rate is the number of births within a population at a specific point in time.
false
The population size of a species capable of being supported by the environment is called its ________.
carrying capacity
Competitive exclusion principle states that two species cannot occupy the same niche in a habitat.
true
A symbiotic relationship where both of the coexisting species benefit from the interaction is called ________.
mutualism
___________________ may physically modify the environment to produce and maintain habitats that benefit the other organisms that use them.
foundation species
The one-child policy was a policy in China that limited population growth by allowing urban couples to have only one child or face a fine.
true
All countries have attempted to reduce the human impact on climate change by increasing their emission of greenhouse gases.
false
Fossil fuels are responsible for dramatically increasing the resources available for human population growth through agriculture (mechanization, pesticides, and fertilizers) and harvesting wild populations.
true
What is true about the organisms found in the yellow region of the cladogram below?
they evolved from a shared ancestor
Using the phylogenetic tree below, choose the species that is most closely related to the gray wolf.
dog
Based on the phylogenetic tree below, what can you conclude about jackals?
The golden jackal does not share the most recent common ancestor with the black-backed jackal.
Based on the phylogenetic tree below, what can you conclude about the use of common names here instead of scientific names?
Common names are not an accurate depiction of phylogenetic relationships.
Which is an accurate way to rewrite the following statement so that it reflects the process of natural selection?
“Horses decided to grow longer legs so they could outrun predators.”
Horses with longer legs were able to outrun predators and, therefore, had higher fitness.
Albinism is a mutation that occurs in a wide range of species and results in organisms with a lack of pigment, so they appear completely white. For which population would you predict an increase in the number of animals with albinism?
a population of arctic foxes that feed on rabbits in the snow
Birds with long, narrow beaks are able to reach insects burrowed in trees but they cannot crush seeds. Birds with short, strong beaks are able to crush seeds but they cannot reach insects. All birds are able to eat plants. If all of these birds are placed on an island with abundant seeds, insects, and plants, what would happen?
Specialization will likely not occur.
Birds with long, narrow beaks are able to reach insects burrowed in trees but they cannot crush seeds. Birds with short, strong beaks are able to crush seeds but they cannot reach insects. All birds are able to eat plants. If these birds are placed on an island with a large amount of insects and a few plants, but no seeds, what would happen?
Over time, there would be an increase in the number of birds with longer beaks.
Birds with long, narrow beaks are able to reach insects burrowed in trees but they cannot crush seeds. Birds with short, strong beaks are able to crush seeds but they cannot reach insects. You arrive on a new island and find that all of the birds have strong, short beaks. What should you expect the food supply to be on this island?
mostly seeds with some plants and a few insects
A flood has occurred and caused a river to move slightly. The river is now separating a population of field mice, as they cannot swim across. Over time, the mice undergo a speciation event. What type of speciation occurred?
allopatric
You are interested in causing a speciation event so that you can see how the process works. Which type of speciation should you choose in order to have the process occur the fastest?
allopatric
During a severe storm, five sandpiper birds were blown to an uninhabited island. You go to study these birds and find that the frequency of genes is changing in every ensuing generation. Why does this occur?
The population size is very small and therefore does not meet the requirements of the Hardy-Weinberg equilibrium.
In a population of sandpiper birds in California, there are two alleles for feather color. The darker allele is found in about 70% of the population. A severe storm moved in, and five sandpipers were blown to an uninhabited island. Over time, they reproduce and form a new population of 250 birds. You go to study these birds and find that in the new population, the darker feather allele is found in only 10% of the population. What is the most likely cause?
genetic drift following a bottleneck event
A species of turtle contains a gene for the presence of spots on the shell, which is the dominant trait. The allele ‘A’ denotes a spotted shell, while ‘a’ denotes a uniform shell. At Hardy-Weinberg Equilibrium, how many turtles have a spotted shell if the frequency of ‘A’ is 0.8?
0.96
__________ will lead to a change in the allelic frequency of a population.
a mutation
Antibiotic resistance occurs when a bacterium is not killed by a specific antibiotic. This usually happens when the bacterium has a plasmid containing a gene for resistance to that antibiotic. Over time, antibiotic resistance has become a significant problem, with many populations of bacteria now resistant to specific antibiotics. By overprescribing antibiotics, humans have increased the rate of what process in bacteria?
natural selection
In a volcanic lake in Nicaragua, there are two species of a small fish called cichlids. Although they are very similar in size, they are slightly different in color and they do not interbreed. Researchers know they are closely related and share a common ancestor. They hypothesize that the fish have speciated recently. Which process of speciation would have caused this?
sympatric
The process of natural selection is often also called “survival of the fittest.” Based on the principles underlying natural selection, which of these would have the highest fitness?
a woman with six kids
Sickle-cell anemia is a disease that causes a change in the shape of red blood cells and causes them to be less effective at carrying oxygen. However, individuals with sickle-cell anemia are resistant to malaria, a parasitic disease carried by mosquitoes that causes severe illness and even death. A global survey of human populations finds higher rates of sickle-cell anemia in countries where the malaria-carrying mosquito is more common. What has caused this increase in sickle-cell anemia in these areas?
natural selection
When analyzing the phylogenetic trees of vertebrates, it is clear that lizards and snakes are older and more ancestral than birds. Based on what you know about how phylogenetic trees work, which came first: the chicken or the egg?
the egg
Which of the following is best at showing the life expectancy of an individual within a population?
life table
Human populations have which type of survivorship curve?
type I
The statistical study of populations is called _____________.
demography
The number of individuals in a population is the…
population size
A ___________________ is the distribution of individuals within a habitat at a particular point in time.
species distribution pattern
Species with limited resources usually exhibit a(n) ________ growth curve.
logistic
The maximum growth rate characteristic of a species is called its ________.
biotic potential
Species that have many offspring at one time are usually…
r-selected
A forest fire is an example of ________ regulation.
density-independent
An accelerating growth pattern seen in populations where resources are not limiting is known as…
exponential growth
A species whose presence is key to maintaining biodiversity in an ecosystem and to disproportionately upholding an ecological community’s structure is called a ________.
keystone species
When an invasive species alters the community structure it is introduced to, what can the consequence be?
extinction of economically important species
reduced predation on some native species
increased predation on some native species
A symbiotic relationship where an organism feeds off another without immediately killing the organism it is feeding on is called…
parasitism
An adaptation in which an organism looks like another organism that is dangerous, toxic, or distasteful to its predators is known as…
mimicry
What is the term used to describe the number of species living in a habitat or other unit?
species richness
A country with zero population growth is likely to be ________.
economically developed
Which type of country has the greatest proportion of young individuals?
countries that are economically underdeveloped
Which of the following is not a way that humans have increased the carrying capacity of the environment?
decreasing use of fossil fuels
Long-term exponential growth carries with it the potential risks of _______.
famine
disease
large-scale death
Human population growth exhibits ______. -
exponential growth
Which of the following is not a property of Hardy-Weinberg Equilibrium?
a small, limited population
When male gorillas reach sexual maturity, they leave their families. This can alter the allele frequencies of the population through which of the following?
gene flow
__________ leads to evolutionary change as it is the reproduction of organisms with traits that allow them to survive environmental change.
natural selection
Would genetic drift happen more quickly on an island or on the mainland?
island
A species is a group of individual organisms that can…
interbreed.
produce fertile, viable offspring.
__________ share a similar embryonic and evolutionary origin.
homologous structures
Which type of speciation involves the geographic separation of populations?
allopatric selection
In sickle-cell anemia, normal homozygous individuals (SS) have normal blood cells that are easily infected with the malarial parasite. Thus, many of these individuals become very ill from the parasite, and many die. Individuals homozygous for the sickle-cell trait (ss) have red blood cells that readily collapse when deoxygenated. Although malaria cannot grow in these red blood cells, individuals often die because of the genetic defect. However, individuals with the heterozygous condition (Ss) have some sickling of red blood cells, but generally not enough to cause mortality. In addition, malaria cannot survive well within these “partially defective” red blood cells. Thus, heterozygotes tend to survive better than either of the homozygous conditions. If 9% of an African population is born with a severe form of sickle-cell anemia (ss), what percentage of the population will be more resistant to malaria because they are heterozygous (Ss) for the sickle-cell gene? (Remember p + q = 1 and p2+ 2pq + q2 = 1)
42%
You have sampled a population in which you know that the percentage of the homozygous recessive genotype (aa) is 36%. Using that 36%, calculate the frequency of the “A” allele. (Remember p + q = 1 and p2+ 2pq + q2 = 1)
0.4
Natural events, such as earthquakes, that kill a large portion of the population refer to the __________ and can magnify the genetic drift in a population.
bottleneck effect
A __________ describes the relationships surrounding an organism, such as from which organisms it is thought to have evolved, to which species it is most closely related, and so forth.
phylogeny
According to Charles Darwin, __________ is the only mechanism known for adaptive evolution.
natural selection
On a phylogenetic tree, a __________ is a group of organisms that descended from a single ancestor.
clade
Differences in breeding schedules can act as a form of reproductive isolation. This is called…
temporal isolation
When similar traits evolve independently in species that do not share a common ancestry, this is called…
convergent evolution
Scientists desire to increase the genetic variance in the cheetah population because it helps reduce the risk of __________, or the mating of genetically similar or related individuals.
inbreeding
Natural selection is limited because it works at the level of the…
individual
Which of the following can cause phenotypic variations in a population?
genetic factors
environmental factors
Which of the following is true about phylogenetic relationships and phylogenetic trees?
They provide information on shared ancestry and evolutionary relationships.
Which of the following is not a way to introduce new genetic variation into a population?
lethal genes
Populations in nature are constantly changing in genetic makeup due to…
genetic drift.
random mutations.
natural selection.
Peppered moths are a great example of natural selection. Prior to the Industrial Revolution, the moths were predominantly light in color, which allowed them to blend in with the light-colored trees and lichens in their environment. But, as soot began spewing from factories, the trees became darker, the light-colored moths became easier for predatory birds to spot, and the darker moths increased in frequency because they had a higher survival rate. In recent years, factories have become cleaner, and less soot is released into the environment. What impact do you think this has had on the distribution of moth color in the population?
moths have shifted to a lighter color
population genetics is the study of…
how selective forces change allele frequencies in a population over time.
One of the original Amish colonies rose from a ship of colonists that came from Europe. The ship’s captain, who had polydactyly, a rare dominant trait, was one of the original colonists. Today, we see a much higher frequency of polydactyly in the Amish population. This is an example of…
genetic drift
founder effect
The __________ is the rate at which a specific allele appears within a population.
allelic frequency
__________ refer to changes to an organism’s DNA and are important in driving diversity and evolution.
mutations
Many evolutionary relationships in the modern tree have only recently been determined due to molecular evidence from…
nucleic analyses
protein analyses
Charles Darwin’s book, __________, outlined in considerable detail his arguments for evolution by natural selection.
On the Origin of Species
__________ occurs when the probability that two individuals in a population will mate is not the same for all possible pairs of individuals in that same population.
non-random mating
Which of the following involves reproductive isolation, but not geographical barriers?
sympatric speciation
