Ecology and Evolutionary Biology: Key Concepts and Q&A
Ecology and Evolutionary Biology: Key Concepts
Ecosystems and Biomes
9.1.2
What is the name for a system formed by the interaction of living organisms with the nonliving physical environment?
Ecosystem.
What is the name for a place where a particular organism lives?
Habitat.
What is the name for a large region with consistent organisms and weather?
Biome.
Which type of biome is the most productive?
Tropical rain forest.
Which type of biome is the least productive?
Tundra.
Which biome is highly productive all year long?
Tropical rain forest.
What is an estuary?
An area where fresh water and salt water mix.
What is upwelling?
Water moving up from the benthic zone.
What is a thermocline?
A line where temperature changes.
A grassland area has many different populations that all live together and interact. What is the name for a group of interacting populations?
Community.
What is the term for a group of mice that all live in the same place?
Population.
A rabbit lives in a wooded area with a small stream running through it. What is the name for this wooded area and the stream?
The rabbit’s habitat.
A fern lives alongside a river and is given water by frequent flooding. What is the name for the area that the fern lives in?
The fern’s habitat.
A deer lives in a forest. It feeds on plants and drinks from a lake. What is the name for the forest that the deer lives in?
The deer’s habitat
Which is a biotic element found in the tropical rain forest biome?
Plants.
Which is an abiotic factor that affects a freshwater ecosystem?
The amount of light.
Which is an abiotic element found in a marine ecosystem?
Water.
Why are marshes more productive than bogs?
Marshes have more water flow.
Why are swamps more productive than streams?
Streams have too much water flow.
Why are rivers less productive than swamps?
The water flow in rivers is too high.
Which part of a lake is most likely to be aphotic?
Benthic zone.
What determines whether a benthic zone in a lake will sustain photosynthesis?
How deep the lake is.
Which part of a lake is most likely to have no photosynthesis?
Benthic zone.
A dam built upriver from a wetland reduces the amount of freshwater that reaches the wetland. What types of species in the wetland would be most negatively affected by this change?
Species that are intolerant of high salinity.
Species Interactions and Succession
9.1.4
What is a nonnative species?
A species that does not normally live in an area.
What is an introduced species?
A species that does not normally live in an area.
What are invasive species?
Nonnative species that are superior competitors.
What is the process of succession?
When a community is replaced by another community.
What is a climax community?
A stable community formed after succession.
Which best describes a climax community?
A very stable community.
What is a cyclical disturbance?
A disturbance that repeats over and over.
What is the name for a disturbance that removes most of the organisms and damages the soil?
Primary disturbance.
What is the name for a disturbance that harms some organisms, but does not hurt the ecosystem?
Secondary disturbance.
What happens when two species occupy the exact same niche?
Only one will survive.
An overlap in their niches.
Two species have the same niche. What is the most likely outcome when one species is the superior competitor?
The other species will become extinct.
As the snow melts from atop mountains in the spring, the rivers below begin to flood. What type of disturbance is this?
Cyclical.
Each winter, ice covers a lake. During this time, fish in the lake have a smaller food supply. What kind of disturbance is this?
Cyclical.
Certain forests in dry climates periodically catch fire, which enables some seeds to germinate. What kind of disturbance is this?
Cyclical.
What type of organisms first move into an area after a primary disturbance?
Small organisms.
What type of organisms first move into an area after a primary disturbance?
Organisms that reproduce quickly.
What type of organisms first move into an area after a primary disturbance?
Small animals that can live in severe conditions.
Why are the tropics the most diverse areas?
They have stable temperatures.
Why are the tropics the most diverse areas?
They have stable levels of moisture.
Which causes the biodiversity of rainforests?
Stable ecosystems.
An extreme disturbance happens in an ecosystem. How does an ecosystem change as succession happens after this disturbance?
Biodiversity in the ecosystem increases.
How does an ecosystem change during succession?
It has more biodiversity.
After a major forest fire, the process of succession begins in an ecosystem. Which best describes how succession changes the ecosystem?
The ecosystem becomes more stable and diverse.
It prevents populations from getting too high.
Population Dynamics
9.2.2
What is one effect of immigration on a population living in an ecosystem?
The population will increase.
What is one effect of immigration on a population living in an ecosystem?
The competition for resources will increase.
A wildfire destroys part of a forest. How will squirrels that live in the forest and depend on trees most likely respond?
Squirrels will emigrate and leave the population.
Which is a density-dependent factor?
Space.
Which is a density-dependent factor?
Water supplies.
Which is a density-independent factor?
Hurricanes.
What is the carrying capacity of an ecosystem?
The largest population that can be supported.
Where does population level off in logistical growth?
At the carrying capacity.
What is the largest population that an ecosystem can support over time?
Carrying capacity.
When can exponential growth happen?
When there are unlimited resources.
When can exponential growth happen?
When there is no competition.
When can exponential growth happen?
When there is unlimited food and space.
What causes populations to compete?
Limited resources.
Why does competition happen?
There are limited resources in an ecosystem.
What causes competition in an ecosystem?
Organisms all want the same resources.
Why did the removal of wolves affect the entire Yellowstone ecosystem?
The ecosystem has a complicated series of interactions.
Why can the removal of one important species affect an entire ecosystem?
All the organisms in an ecosystem interact with each other.
Why did the removal of wolves affect the entire Yellowstone ecosystem?
It changed the balance of many different interactions.
In a certain ecosystem, owls are predators for mice. The owl population increases, and they eat more mice. This causes the mouse population to decrease. What happens next?
The population of owls decreases.
Wolves are predators for hares. The wolf population increases. What happens next?
The death rate of hares increases.
In an ecosystem in Africa, lions are predators for zebras. The lion population increases, and they eat more zebras. This decreases the zebra population. What happens next?
The death rate of lions increases.
Hardy-Weinberg Principle
9.2.4
What idea did Hardy and Weinberg disprove?
Dominant alleles become more common in each generation.
What question did Hardy and Weinberg want to answer?
How does allele frequency change between generations?
What was the purpose of Hardy and Weinberg’s work?
To determine how allele frequency changes.
What is the allele frequency?
The distribution of alleles in a population.
What is the term for all the types of alleles that exist in a population?
Gene pool.
What is the phenotype frequency?
The distribution of traits in a population.
In the Hardy-Weinberg equation shown below, p is the frequency of the dominant allele, and q is the recessive allele. What does p2 represent in the equation?
The frequency of the homozygous dominant genotype.
In the Hardy-Weinberg equation shown below, p is the frequency of the dominant allele, and q is the recessive allele. What does q2 represent in the equation?
The frequency of the homozygous recessive genotype.
In the Hardy-Weinberg equation shown below, p is the frequency of the dominant allele, and q is the recessive allele. What does 2pq represent in the equation?
The frequency of the heterozygous genotype.
Which of these is one of the conditions for Hardy-Weinberg equilibrium?
The population must be infinitely large.
In order to use the Hardy-Weinberg equation to calculate genetic variation in a population, which of the following conditions must exist in the population?
All organisms must reproduce.
Which of these is one of the conditions for Hardy-Weinberg equilibrium?
Mutation cannot occur.
What happens when a population is in Hardy-Weinberg equilibrium?
Allele frequency is stable.
What happens when a population is in Hardy-Weinberg equilibrium?
The distribution of alleles does not change from one generation to the next.
What happens when a population is in Hardy-Weinberg equilibrium?
The phenotype frequency does not change.
The phenotype frequency in a population changes after each generation. Which would most likely be causing this?
Competition between organisms.
The phenotype frequency in a population changes after each generation. Which would most likely be causing this?
Some traits give an advantage.
The phenotype frequency in a population changes after each generation. Which would most likely be causing this?
Organisms compete for shelter.
A trait has two alleles, represented by p and q. If p = 0.35, what is q?
0.65.
A trait has two alleles, represented by p and q. If p = 0.22, what is q?
0.78.
A trait has two alleles, represented by p and q. If p = 0.89, what is q?
0.11.
A plant has two alleles for color. The red allele is recessive, and is represented by q. The purple allele is dominant, and is represented by p. If 30 of 100 organisms are red, what is q?
0.55.
A plant has two alleles for color. The red allele is recessive, and is represented by q. The purple allele is dominant, and is represented by p. If 59 of 100 organisms are red, what is q?
0.77.
A plant has two alleles for color. The red allele is recessive, and is represented by q. The purple allele is dominant, and is represented by p. If 76 of 100 organisms are red, what is q?
0.87.
Adaptation and Natural Selection
9.3.2
What question did Charles Darwin attempt to answer?
Why do organisms in different places have different traits?
What question did Charles Darwin attempt to answer?
Why do different organisms live in different places?
What question did Charles Darwin attempt to answer?
Why do different regions have different organisms?
What is a reproductive strategy?
The method an organism uses to produce offspring.
What is a reproductive strategy?
The way that a species creates offspring.
What is a reproductive strategy?
The way a species produces offspring.
Which is true about adaptations?
They are genetically acquired traits.
They are passed along to offspring.
Which is true about adaptations?
Organisms are born with them.
Why are certain traits adaptations in one environment, but not in another?
Different environments have different abiotic conditions.
Why are certain traits adaptations in one environment, but not in another?
An adaptation must fit the environment.
Why are certain traits adaptations in one ecosystem, but not in another?
Ecosystems can have different conditions.
How are finches in the Galápagos Islands a good example of adaptation?
They have adapted to be able to get different types of food.
How are finches in the Galápagos Islands a good example of adaptation?
Finches have developed many different adaptations.
How are finches in the Galápagos Islands a good example of adaptation?
Each species has a special beak adaptation.
Which is an adaptation?
A rabbit has fur that blends in with snow.
Which is an adaptation?
A camel has humps that store fat.
Which is an adaptation?
A bird has feathers that help it fly farther.
In what way do adaptations help the survival of a species?
It increases the biodiversity of the species.
How do adaptations affect a species?
They make the species more likely to survive.
How do adaptations affect a species?
They make the species more genetically diverse.
Which adaptation would help a plant live in a desert?
Leaves that hold water.
Why are small leaves an adaptation in a desert environment?
They minimize water loss.
Why is night vision an adaptation for owls in a desert environment?
It allows them to hunt when it is cooler.
Natural Selection and Fitness
9.3.4
What is the fitness of an organism?
The ability to survive and reproduce.
What is the term for an organism’s ability to survive and reproduce?
Fitness.
What term is used to describe how well an organism functions in its environment?
Fitness.
What is the name for the process that causes a species to evolve?
Natural selection.
What does natural selection cause?
Evolution.
New generations are better suited to their environment than the first generation. What is this called?
Descent with modification.
Which best summarizes the concept of natural selection?
Organisms best adapted to their environments survive.
Which best summarizes the concept of natural selection?
The fittest organisms survive and reproduce.
Which best summarizes the concept of natural selection?
The fittest organisms are selected for.
How does natural selection lead to evolution?
Small changes add up over time.
How does natural selection lead to evolution?
A species can gradually change into a new species.
How does natural selection lead to evolution?
Many small changes can create a whole new species.
Which best summarizes the peppered moths in England after the Industrial Revolution?
The black color became an adaptation.
Which best summarizes the peppered moths in England after the Industrial Revolution?
The phenotype frequency changed.
Which best summarizes the peppered moths in England after the Industrial Revolution?
The allele frequency changed.
How do peppered moths after the Industrial Revolution show the process of natural selection?
The black moths were more fit for survival, so their phenotype frequency increased.
How do peppered moths after the Industrial Revolution show the process of natural selection?
Black moths were selected for when the trees turned black.
How do peppered moths after the Industrial Revolution show the process of natural selection?
The moths with the highest fitness were selected for.
What must be true for natural selection to happen?
There must be genetic variation in the population.
What must be true for natural selection to happen?
Resources must be limited in the ecosystem.
Which causes natural selection to occur?
The presence of predators.
Mechanisms of Evolution
10.1.2
Which best describes genetic drift?
Random changes in allele frequency.
What causes genetic drift?
Random chance.
Which of the following would cause gene flow?
Individuals moving into a population.
Which of the following would cause gene flow?
Individuals moving out of a population.
What causes gene flow?
Movement of gametes.
What is artificial selection?
When humans breed an animal for a certain trait.
What is it called when a high percentage of the species on Earth dies off?
Mass extinction.
What is a trait called when it is controlled by more than one gene?
Polygenic.
When is genetic drift a major factor in evolution?
When there is low gene flow.
When is genetic drift a major factor in evolution?
When there is no selective pressure.
When is genetic drift a major factor in evolution?
When there is a bottleneck.
Which feature would you expect to find in a population in which sexual selection depends on female choice?
Bright-colored males.
Which feature would you expect to find in a population in which sexual selection depends on male competition?
Large males.
In a species of bird, the males compete to try to fertilize the females. Which trait would you expect these birds to have?
Males that are much larger than females.
Under which condition would a mutation have the most impact on allele frequency?
When the population is small.
Under which condition would a mutation have the most impact on allele frequency?
There is no gene flow.
A flood kills most of the population of ants that live near a river. After the flood, the ant population increases, but its allele frequency is different. What type of situation is this?
Bottleneck.
A large mouse population lives in a forest. A small number of mice are separated from the population during a forest fire. This small group forms their own population with a different allele frequency. What type of situation is this?
Founder.
The number of trout in a lake drops when the lake is polluted. The trout population later increases, but the allele frequency is different than it was before the pollution. What type of situation is this?
Bottleneck.
Which tends to increase genetic variation in a population?
Mutation.
Which will make a population have more genetic variation?
Mutation.
Which increases genetic variation?
Mutations.
Evidence for Evolution
10.1.4
What is an index fossil?
A fossil found in rocks from one time period.
What is an index fossil?
A fossil found in rocks from one time period.
What makes a fossil an index fossil?
The fossil was formed only during a certain short time period.
What is a homologous structure?
A structure with similar shape but a different use.
What is a vestigial structure?
A structure that has no use in the organism.
What is the term for a structure that has no use in an organism?
Vestigial.
What is the term for the remains of a once-living organism?
Fossil.
What is a fossil?
The remains of a dead organism.
What is the term for a preserved footprint left behind by an animal?
Fossil.
Which would be a homologous structure to a human arm bone?
A bird’s wing bone.
Which is a homologous structure to the human forearm?
The wing of a bat.
Which is a homologous structure to the human forearm?
The leg of a horse.
Why is evolution considered a theory?
It is backed up by scientific evidence.
Which best describes evolution?
It is a theory backed up by scientific evidence.
Which best describes the theory of evolution?
A theory supported by evidence.
How is radioactive dating important for providing evidence for evolution?
It tells you how old fossils are.
How is radioactive dating important for providing evidence for evolution?
It allows scientists to organize the fossil record.
How is radioactive dating important for providing evidence for evolution?
It tells you when the animal that made a fossil was alive.
How is the fossil record evidence for evolution?
It shows how organisms change over time.
How can embryonic development be used as evidence for evolution?
Related species have similar embryos.
How is DNA used as evidence for evolution?
All species have the same genetic code.
Why are vestigial structures not removed by natural selection?
They do not harm the organism.
Why are vestigial structures not removed by natural selection?
Natural selection removes only harmful traits.
Why are vestigial structures not removed by natural selection?
Nature selects against only harmful traits.
Speciation and Adaptive Radiation
10.2.2
What is speciation?
The formation of species.
Which must be true for two organisms to be considered the same species?
They can produce fertile offspring.
What is speciation?
The formation of two or more species from a common ancestor.
What is adaptive radiation?
When many species share a single ancestor.
Which best describes adaptive radiation?
Biodiversity resulting from few ancestors.
What is the term for biodiversity that results from few ancestral species?
Adaptive radiation.
What is a hominid?
Any bipedal primate.
What is the term for any primate that walks on two feet?
Hominid.
What is the term for any bipedal primate?
Hominid.
How does reproductive isolation cause speciation?
It reduces gene flow.
How does reducing gene flow cause speciation?
It allows divergence to occur.
How does reducing gene flow cause speciation?
It allows populations to become genetically different.
When a population is split into smaller groups, why do these groups develop different traits?
Evolutionary mechanisms work on the two subgroups independently.
When a population is split into smaller groups, why do these groups develop different traits?
Forces like natural selection and genetic drift affect the genes of the two subgroups differently.
When a population is split into smaller groups, why do these groups develop different traits?
Mutations that arise in one group are not passed to the other group through reproduction.
Why does geographic isolation cause speciation?
It prevents gene flow between populations.
Why does geographic isolation cause speciation?
It allows two populations to evolve separately.
Why does geographic isolation cause speciation?
It prevents the two populations from interbreeding.
When is speciation complete?
When the two populations can no longer interbreed.
Which is a part of the process of speciation?
Divergence.
What must happen for speciation to occur?
A population must be isolated in some way.
Taxonomy and Classification
10.2.4
What is taxonomy based on?
Evolutionary relationships.
Which statement is true about living things that share a recent common ancestor?
They will probably be classified in the same family or genus.
Two species are classified in the same genus. How does this classification reflect the evolutionary relationship between the two species?
It means the species shared a common ancestor in the recent past.
What is a clade?
A group of organisms with a shared ancestor.
What is a cladogram?
A diagram showing evolutionary relationships.
What is cladistics?
A system that groups organisms by ancestry.
Which of these groups is the smallest level of classification?
Genus.
Which of these groups is the smallest level of classification?
Family.
Which of these groups is the smallest level of classification?
Order.
What genus are humans in?
Homo.
What is the species name for humans?
Sapiens.
What is the scientific name for humans?
Homo sapiens.
Which organisms are most closely related? Remember, the name of an organism is in the torm Genus species.?
Aythya affinis and Aythya marila.
Which organisms are most closely related? Remember, the name of an organism is in the form Genus species.?
Rana capito and Rana clamitans.
Which of these organisms are the most closely related? Remember, the name of an organism is in the form Genus species.?
Nerodia sipedon and Nerodia Irasciala.
Which organisms would share the most characteristics?
Organisms in the same order.
Which organisms would look most alike?
Organisms in the same family.
Which organisms would have the most similar traits?
Organisms in the same order.
What causes a branch in a cladogram?
A derived trait.
What causes a branch in a cladogram?
A new trait.
What dos each branch in a cladogram represent?
A different derived trait.
When is cladistics more useful than Linnaean taxonomy?
When you want to know ancestral relationships.
When is cladistics more useful than Linnaean taxonomy?
When you are analyzing DNA of organisms.
When is cladistics more useful than Linnaean taxonomy?
When you want to determine the order of evolution.
10.3.2
What was the purpose of Miller and Urey’s experiment?
To find out howbiological molecules could have first
formed.
What was the purpose of Miller and Urey’s experiment?
To see if biologicalcompounds could form spontaneously on early Earth.
What was the purpose of Miller and Urey’s experiment?
To see if simple molecules can combine spontaneously.
Which is a characteristic of something in the domain Archaea?
Unicellular.
Which is a characteristic of something in the domain Bacteria?
Unicellular.
Which is a characteristic of something in the domain Archaea?
No cell nucleus.
Which is not a kingdom in the Eukarya domain?
Archaea.
Which is not a kingdom in the Eukarya domain?
Bacteria.
Which is a kingdom in the Eukarya domain?
Protista.
How are organisms in the domains Bacteria and Archaea similar?
They are unicellular.
How are organisms in the domains Bacteria and Archaea similar?
They are prokaryotes.
How are organisms in the domains Bacteria and Archaea similar?
They lack a nucleus.
How do scientists think protobionts formed?
Biological molecules were trapped in molecular
bubbles.
What was formed when biological material became trapped in a molecular bubble?
Protobionts.
How do scientists think protobionts formed?
Cell-like structures formed from molecular bubbles.
How are organisms in the domain Eukarya different from those in the domain Archaea?
Eukaryotes have more than one cell.
How are organisms in the domain Eukarya different from those in the domain Archaea?
Eukaryotes have organelles in membranes.
How are organisms in the domain Eukarya different from those in the domain Archaea?
Eukaryotes have a nucleus.
Why are archaea in a different domain from bacteria?
They are thought to have separate paths of evolutionary development.
Why are archaea in a different domain from bacteria?
They developed along different evolutionary paths.
Why are archaea in a different domain from bacteria?
Thev had independent evolutionary development.
Which is used as evidence for the idea that eukaryotes formed from prokaryotes?
Mitochondria and Chloroplasts have their own DNA.
Which is used as evidence for the idea that the domain Eukarya evolved from unicelular
organisms?
Mitochondria and chloroplasts have their own DNA.
Which is used as evidence for the idea that multicelular organisms evolved from prokaryotes?
Mitochondria and chloroplasts have their own DNA.
10.3.4
What is the term for a plant that produces a seed with a protective cover?
Angiosperm.
What is the term for a plant that produces a seed without a protective Cover?
Gymnosperm.
What is an angiosperm?
A plant that produces seeds with protective covers.
What is a gametophyte?
A haploid form of a plant.
What is a sporophyte?
A diploid form of a plant.
What is the term for the haploid form of a plant?
Gametophyte.
What is a vertebrate?
A deuterostome with a backbone.
Which are deuterostomes?
Humans.
Which are protostomes?
Worms.
Which best describes the earliest land plants?
Thin leaves.
Which best describes the earliest land plants?
Did not grow very tall.
Which best describes the earliest land plants?
Lived in close contact with water.
Which animal adaptation happened before the others?
Bilateral symmetry.
Which animal adaptation happened before the others?
Development of a caelom.
Which animal adaptation happened before the others?
Tissue development.
Why do fungi need to live in moist areas?
Their large surface areas make them dry out easily.
How are fungi helped by the high surface areas of their filaments?
They help them absorb nutrients.
Why are fungi unable to live in dry areas?
They cannot trap moisture.
Which is an adaptation that helped plants survive
on land?
Vascular systems.
Which is an adaptation that helped plants survive on land?
Production of seeds.
Which is an adaptation that helped plants survive on land?
Formation of cuticles.
What happened after plants first became able to live on land?
Adaptive radiation spread them into many land niches.
How did adaptive radiation affect plants after they first moved to land?
They evolved to fill the niches found on land.
After plants first moved to land, what happened?
Adaptive radiation formed many I new land plant species.