bio exam 3: evolution and natural selection
food chain
is a linear representation of energy movement in a community. Energy moves from the producers, which convert solar energy into biomass, to each level in the community.
Acid rain
is one consequence of disrupting the sulfur cycle. Sulfur released by smokestacks mixes with water and rains down as sulfuric acid
The physical and biotic changes that people make to the land surface of Earth are referred to as _______
land transformation or land-use change
biotic
living organisms
A limitation of the morphological species concept is that some individuals of the same species can
look quite different
The total number of individuals of a species per unit area is referred to by ecologists as population
population density
Dr. Cherry monitors populations of the threatened plant species Boltonia decurrens, a species that only lives in the Illinois River Valley in Illinois. She visits each population annually to count the number of plants and monitor the populations. This type of study is known as
population ecology.
The total number of individuals in a population is the
population size
How is a species defined according to the biological species concept?
populations that can interbreed to produce fertile offspring
Phylum - Arthropoda
segmented body, exoskeleton for protection *****most species rich (most diverse) group of animals
Weather
short-term atmospheric conditions in a limited geographic area Today's temperature, precipitation, wind, humidity, and cloud cover
The term "sustainable" describes
an action or process that can continue indefinitely without using up resources or causing serious damage to the environment.
limiting factor
any factor that stops a population from growing and reaching carrying capacity
What determines carrying capacity for a population in a given environment?
any limiting resource
This biome is dominated by deciduous trees (trees that lose their leaves every winter) and have a higher species diversity than boreal forests. This biome has typically rich soil and the climate is characterized by snowy winters and warm, moist summers. Common trees include oak, maple, hickory, beech, and elm. Amphibians (frogs and salamanders) and reptiles (including turtles) are common. Also commonly observed are squirrel, rabbits, deer, raccoon, and beavers. Carnivores include bobcats, mountain lions, and bears. This biome is primarily located at the mid-latitudes.
temperate deciduous forest
Which of the following variables are abiotic factors that affect ecosystems?
temperature sunlight rocks
population size
total number of individuals in a population
species richness
total number of species living in a community
Biomagnification/Bioaccumulation
toxins accumulate in the fatty tissues of organisms and magnify as you move though the food chain Human-made chemicals can be ingested, inhaled, or absorbed by organisms; if a chemical binds to cells or tissues and stays there at a concentration higher than the surrounding environment, then we say it bioaccumulates in an individual.
terrestrial biomes
tundra (alpine and arctic) desert grassland taiga (boreal forest and coniferous forest) tropical rain forest temperate "deciduous" forest
trophic cascade
when you disturb the balance of the ecosystem to the point that it exceeds resilience of the system and it collapses
Individuals can leave their population through which two processes?
✔ death✔ emigration
Speciation is the process
by which one species splits to form two species or more. The evolution that occurs when there is a physical barrier between two populations and these two populations evolve away from one another is allopatric speciation. The two populations may continue to diverge, becoming more and more different because of their geographic isolation. Ecological isolation refers to two closely related species in the same territory being reproductively isolated by slight differences in habitat. The formation of new species in the absence of a physical barrier is called sympatric speciation. Sympatric speciation is a particularly important process in plants.
An ecosystem consists of
communities of organisms and the physical environment they share.
A ___ is a group of species that occupy the same area.
community
When both interacting species are negatively affected, this is called
competition
Eutrophication
introduction of nutrients into a system. Changes the quality of environment nutrients increase, algae increase, bacteria increase, oxygen decreases, diversity decreases
boreal forest
A forest biome made up primarily of coniferous evergreen trees that can tolerate cold winters and short growing seasons
Complete the following passage regarding biological diversity.
A(n) community is a group of species that occupy the same area. When studying the diversity of a group of species, ecologists use two measures: One is a count of the total number of species in the area, which is called species richness. The other is a measure of how common the species are, compared to each other, which is called relative species abundance.
estuary
Among the most productive on Earth, this biome is located in areas where rivers meet seas.
Kingdom: Plantae
Autotrophic, multicellular organisms that perform photosynthesis *Bryophytes (mosses and liverwarts) -Waterproof cuticle to hold in moisture, beginnings of roots *Ferns -vascular tissue, root systems *Gymnosperms Evolve specialized reproductive structures pollen, (structure that contains sperm), seeds *Angiosperms (flowering plants) -very diverse. Flower as reproductive organ with ovary to protect seed. -Fruit-eatable ovarty that helps disperse seeds
Prezygotic Reproductive Barriers:
Behavioral barriers -Differences in mating behavior may interfere with reproduction -Example: many birds have mating songs or dances Mechanical barriers -Incompatible sexual organs insects -"lock & key" Gamete Compatibility Isolation -Eggs and sperm of different species unable to fuse -Common among organisms that release gametes into the environment
Interspecific competition
Between different species
decomposers
Break down organic matter
taxonomy
Classifying organisms into groups based on morphological or genetic characteristics Classify= putting organisms into groups (taxa) Why? For Organization and communication
Speciation
Creation of new species rates differ among organisms When one species splits = 2 new species Genetic Divergence Increase biodiversity Caused by: REPRODUCTIVE ISOLATION
levels of classification
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
The fossil record
Enables biologists to reconstruct the history of life on Earth Provides some of the strongest evidence that species have evolved over time Contains examples of how new groups of organisms arose from previously existing organisms
Three Domains of Life
Every living organism on Earth fits into one of these 3 domains. 1. Bacteria 2. Archaea 3. Eukarya
Limitations of Biological Species Concept
Fossils -No record of reproduction Asexual reproduction -Bacteria Hybrids -Shrub oaks at different elevations: -Gray—lower -Gambel—higher -Hybrids—intermediate
grassland
Found in both temperate and tropical latitudes, this biome doesn't have enough precipitation to sustain tree growth, but it can sustain other plants.
tundra
Found near the poles or on mountaintops, this biome is devoid of trees due to short growing season.
Prezygotic Reproductive Barriers
Geographic or spatial barriers Species are separated by distance Temporal barriers Difference in reproductive timing flowers blooming @ different times
Which of the following is NOT considered a prezygotic reproductive barrier that could cause speciation without geographic isolation?
Hybrids produced by two species survive poorly FEEDBACK: Although all of these answers are reproductive barriers that isolate two species and lead to sympatric speciation, only the poor survival of hybrids is a postzygotic barrier, which occurs after a zygote is formed.
Which of the following is incapable of evolving?
Individuals cannot evolve. Only populations can evolve.
Individuals evolve over their lifetime.
Individuals do not evolve, but mutations can produce new alleles in the population.
Stabilizing Selection
Intermediate phenotype has advantage over both extremes.
monotremes
Monotremes lack a placenta. Offspring hatch from an egg.
abiotic
Non-living
What will happen in an ecosystem if the rate of primary productivity exceeds, or is greater than the rate of decomposition?
Organic matter will accumulate. If NPP exceeds the decomposition rate, organic matter will build up. Indeed this is what happens in some wetland ecosystems, where poorly decomposed plant material accumulates in the form of peat. Organic matter will take longer to degrade. If NPP exceeds the decomposition rate, organic matter will not turn over as quickly. Indeed this is what happens in some wetland ecosystems, where decomposition rates are slowed due to water saturation.
producers
Organisms that make their own food (convert sunlight to energy; autotrophs)
Charles Darwin's On the Origin of Species by Means of Natural Selection
Published November 24, 1859 Focused biologists' attention on the great diversity of organisms Challenged the notion that the Earth was relatively young and populated by unrelated species
class reptilia
Reptiles evolved as the first creatures that did not need to return to water to reproduce. -Internal fertilization -Epidermal Scales -Amniotic Egg-Major adaptation An egg with four membranes that allows an embryo to develop away from water
Convergent evolution:
Results in organisms that appear very much alike despite vastly dissimilar genetics Not common descent from common ancestor The characteristics that result are called analogous traits (not homologous).
logistic growth
S curve limited resource
Special cases of natural selection
Sexual Selection Artificial selection
Mutations can be...
Silent Harmful Beneficial Sometimes it Depends on Environment
A population experiencing a genetic bottleneck would have which of the following characteristics?
Small population size
Which of the following explains why 90 percent of the energy is not transferred from one trophic level to the next?
Some energy is lost as metabolic heat. Some energy is not fully consumed. Some energy is expelled as waste.
Climate Change Has Brought Many Species to the Brink
Temperature increases have changed the biotic component of some ecosystems. Many northern ecosystems are shifting poleward and some are running out of room to migrate into. Pest species, from poison ivy to mosquitoes, may benefit because they are more adaptable Invasive species taking over.
transfer of energy
The conversion of one form of energy into another, or the movement of energy from one place to another.
The most important role that decomposers play in ecosystems is releasing energy from dead organisms, freeing it up to be used by living organisms.
The most important role that decomposers play in ecosystems is freeing up nutrients from dead organisms. Energy is constantly added to ecosystems in the form of sunlight.
what is ecology
The study of interactions between organisms and their environment
Secondary consumers:
Wolves eat elk (primary consumers) that ate aspens (producers).
Gene flow can occur when
an organism travels to a new population and brings with it new alleles.
adaptations are
beneficial mutations. -they are complex, costly, -when the majority of the population has the desired population, you can say that natural selection has has taken place and the species is adapted
evolution is
change in allele frequencies over time
density dependent factors
competition, predation, parasitism, disease
Community Interactions:
competition, predation, symbiosis, mutualism, commensalism, parasitism
All populations
contain individuals of one species that interact in a defined area.
Factors that limit population growth
density dependent and density independent
When a population is held in check by factors not related to population density, this is referred to as __________ population change.
density-independent
What is the ultimate source of genetic variation?
mutation
adaptive evolution
over time
Water transformation refers to
refers to physical and biotic changes that people make to the waters of our planet. Aquatic ecosystems are severely threatened by urban development, sewage, nutrient runoff, pollution, and overfishing.
Interference (Direct) competition
species compete directly for shared resources (ecological niche)
Most human individuals harbor at least 500 different species of bacteria in their intestinal tracts, many of which are beneficial to human health. However, taking antibiotics kills not only the targeted disease-causing bacteria but also other beneficial bacteria located in your intestines. When antibiotics reduce the number of bacterial species in your intestine, they are reducing your bacterial _____. Taking antibiotics also lowers the total number of bacteria in your intestinal community, reducing the number of individuals of each species. By lowering the number of bacteria of each species, antibiotics are reducing _____.
species richness; relative species abundance
Increasing greenhouse gases
speeds global warming.
Ecological footprint is a measure of
sustainability
ecosystem services
the beneficial results that come from successful ecosystem interactions (both for nature and human needs)
Adaptation
the special characteristics that help an organism live and survive.
Terrestrial biomes are land biomes
usually named after the dominant vegetation in the area
eutrophic
well fed (many nutrients)
Sickle-cell disease
-Affects about one out of every 500 African Americans -Confers resistance to the disease malaria -Is adaptive in the African tropics where malaria is common
food webs
A complex diagram representing the many energy pathways in an ecosystem
temperate deciduous forest
A forest characterized by trees that shed their leaves in the fall. Range of the temperatures can be extreme. Vegetation changes with the seasons because of the temperature.
A conservation organization is looking to preserve highly productive habitats in the Amazon region of South America before developers destroy the biomes present. There are two parcels of land available for purchase: a 15 km2 (15,000,000 m2) area of tropical grassland, and a 9 km2 (9,000,000 m2) area of wetlands. The organization does not have enough funds to purchase both. Which parcel would preserve the greater amount of primary productivity?
Although TROPICAL GRASSLANDS produce less per square meter, the greater area results in more overall primary productivity as compared to the wetlands parcel: 26,550,000,000 grams versus 23,400,000,000 grams for the wetlands parcel.
convergent evolution
Evolution toward similar characteristics in unrelated species
Which of the following evolutionary mechanisms acts to slow down or prevent the evolution of reproductive isolation?
Gene flow is also called as migration. It describes any movement of genes from one population to another. Other options have a role to play in isolation
Which of the following must take place for speciation to occur? A.) Hybridization B.) Geographic isolation C.) Polyploidy D.) Genetic divergence
Genetic divergence FEEDBACK: Some of the other answers listed are frequently associated with speciation, but only genetic divergence is essential.
warmer habitat
More active sweat glands cool the horse more readily, keeping it from overheating.
Which of the following statements about genetic variation is true?
Mutation is the ultimate source of new alleles. Mutation is the only source of new alleles and a major source of genetic variation. Only mutations in gametes can be inherited.
_____ are the ultimate source of all genetic variety in the population and are RANDOM
Mutations
marsupial
Offspring are nourished by a simple placenta. Offspring are born less developed. Offspring complete development in an external pocket or pouch while nourished by milk.
Directional Selection
One extreme phenotype has advantage over other phenotypes.
Which of the following represents a scenario that could lead to sympatric speciation?
Some individuals in a population of mushrooms that reproduce in the summer begin to reproduce in the spring. This is an example of ecological isolation, where two populations become reproductively isolated because they are reproducing in different seasons. Some individuals in a population of flies begin to exhibit a different mating dance. This is an example of behavioral isolation, where two populations become reproductively isolated because they are practicing different courtship behaviors. Situations that lead to sympatric speciation prevent individuals that live in the same habitat from reproducing with one another.
Sexual selection occurs when
a characteristic or set of characteristics makes individuals better at finding mates. When one sex prefers certain traits in a mate, this can result in the evolution of sexual dimorphism, or a large difference in the appearance of males and females of the same species. However, some of the characteristics that allow for better mating potential may actually be detrimental to survival.
Species
a group of individuals that can breed with each other and produce fertile offspring Morphologically similar Ex: Bald eagles Alaska (top) Colorado (bottom)
keystone species
a species that has a disproportionately large effect on its environment relative to its abundance. it holds the community together (exaple" gray wolves in yellowstone)
tundra
a vast, flat, treeless Arctic region of Europe, Asia, and North America in which the subsoil is permanently frozen. alpine and artic
ecosystem
all of the organisms in an area and the physical surroundings in which they interact
two types of speciation
allopatric and sympatric
carnivores
meat eaters
Phylum - Echinodermata
sea stars water vacular system (beginning of cirulatory system)
tragedy of the commons
situation in which people acting individually and in their own interest use up commonly available but limited resources, creating disaster for the entire community
Prokaryotes
*Prokaryotes include both Bacteria and Archaea. -*Prokaryotes appeared on Earth about 3.5 billion years ago. *About 2.8 billion years ago, photosynthetic bacteria evolved and began producing oxygen as a waste by-product. *Archaea can withstand harsh environments
An _1___ is a group of communities interacting with one another and the physical environment. The factors that influence ecosystems include the interactions of organisms, which are called _2_ factors, and impacts from nonliving aspects of the environment, which are called _3_ factors. The combination of these factors produces distinct regions of different kinds of ecosystems across Earth, known as __4__. For example, a terrestrial habitat that receives little water, and therefore has few plants, is called a __5__.
1 communities 2 biotic 3 abiotic 4 biomes 5 desert
Single-celled organisms that reproduce rapidly are excellent models of population growth. Using laboratory growth media, a population of paramecia first experiences 1 growth, which occurs when a population increases by a constant proportion over a constant time interval. This type of growth is represented by a(n) 2 growth curve. However, as resources become limited, growth slows and levels off as the population reaches 3. This type of growth, in which the paramecia experience exponential growth at first but then stabilize at the maximum population size that can be sustained by the culture media, is called 4 growth and is represented by a(n) 5 growth curve.
1 exponential growth 2 j-shaped growth curve 3 carrying capacity 4 logistic 5 s-shaped growth curve
prezygotic barrier
1. If the reproductive anatomy of two populations is incompatible, mating cannot occur. 2. If the timing of mating of two populations is different, mating cannot occur.
4 conditions that explain why natural selection happens
1. Individuals within a population differ 2. The differences are, at least in some part, passed down from parents to offspring. 3. Some individuals are more successful at surviving and reproducing then others. 4. The successful individuals succeed because of variant traits they have inherited and will pass onto their offspring.
4 mechanisms that cause evolution
1. Mutation (random/rare) -silent, harmful, beneficial, (sometimes it depends on environment) 2. Gene flow 3. Genetic drift -founder effect -bottle neck effect 4. Natural selection -directional selection, stabilizing selection, disruptive selection -artificial selection
When a natural population is first established in a new habitat, it usually has a 1 population size. During the first few generations, the population growth rate is likely to be 2. After many generations, the population growth rate will likely begin 3 due to 4 resources. The maximum number of individuals that the habitat can support is called the 5, which is a feature of the 6.
1. Small 2. Increasing 3. Decreasing 4. Scarcity of 5. Carrying capacity 6. Habitat
Place the following events in the order they must occur for natural selection to lead to evolution.
1. Variation must exist first. 2. The rabbits' eating habits affect which alleles are the most adaptive, and the thorn-bearing shrubs survive to reproduce in greater number. 3. Since the thorn-bearing plants survive to reproduce more, their genes (and phenotypes) become more prominent.
The table below shows the size of a population of palm trees in a swamp over a 25-year period. What is the doubling time of this population in years?
10 years The doubling time is the amount of time it takes for a population to double in size. After 10 years, the palm tree population indeed doubles from 10 to 20 individuals. Therefore the doubling time of this population is 10 years.
The Arctic tundra has warmed ~3.5°C, resulting in soils thawing to greater depths and increased rates of decomposition. Scientists indicate the tundra has experienced a 20% increase in primary productivity as a result. If the tundra had averaged 240 g/m2/year productivity, what would the current productivity be?
288 g/m2/year As the Arctic tundra warms, the permafrost thaws and increased decomposition makes more nutrients available, boosting primary productivity.
A bear species is the only top predator in a mountain ecosystem. The primary productivity of the ecosystem is 10,000 calories per day. The bear species gains 100 calories of energy per day. Assuming that 90% of energy is lost as it is transferred to each new trophic level, what is the likely number of trophic levels in this ecosystem?
3 trophic levels Since the primary productivity of the ecosystem is 10,000 calories per day and 90% of the energy is lost at each trophic level, the bear is likely the third trophic level in this ecosystem. The first trophic level has a productivity of 10,000, the second would have a productivity of 1,000, and the third would have a productivity of 100.
Two populations of mice are geographically isolated from each other when a river forms. The two populations develop morphological differences. After 100 years, the river changes course and the two populations move into the same area. Which of the following would indicate the two populations most likely represent two separate species?
A DNA analysis indicates significant genetic differences between the two populations. Genetic divergence between the two populations is required for a single species to split into two. A significant difference in DNA indicates these two populations have already diverged and are most likely two separate species.
grassland
A biome found in the dry temperate interiors of continents. This biome is characterized by rich soil, moderate rainfall, a hot, dry climate, thick grasses, and herds of grazing animals.
Which of the following are examples of natural selection?
A hawk preys on the more visible mice in a farm field, leading to a higher rate of survival in less visible mice. Antibiotic resistance develops in a bacterial population as individuals share genetic information with each other and antibiotic-resistant cells reproduce more. Brown dragonflies living at the edge of a pond survive and reproduce more than bright yellow dragonflies living in the same area. The development of antibiotic resistance in bacteria occurs when bacteria that are resistant to antibiotics are the only ones that survive and reproduce in the presence of the antibiotic. When a hawk preys on the more-visible mice in the field, the less-visible mice and their more-advantageous coloring survive and reproduce at a higher rate. Brown dragonflies surviving and reproducing more than bright yellow dragonflies must have advantageous traits that help them survive. These are all examples of natural selection, that is, the process by which individuals with advantageous traits survive and reproduce at a higher rate than other individuals.
Quaternary consumer:
A killer whale that eats a leopard seal (tertiary consumer) that ate a sea bass (secondary consumer) that ate a krill (primary consumer) that ate a phytoplankton (producer)
Which population would be most likely to survive and evolve with a change in the selective environment?
A large population with high genetic diversity Large populations with high genetic diversity are the most likely to survive and evolve because they would be best able to respond to changes in selective pressure, such as a change in the environment. The greater the genetic diversity is, the more likely that individuals in the population have traits that help them to survive and reproduce more than other individuals in a changed environment.
Which of the following is a situation in which a population's size is controlled by a density-independent factor?
A late spring freeze kills young vegetation that a population of insects relies on as a food source.
natural selection acts upon
Acts upon natural variation that already exists among individuals in a population Most of the variation is heritable Better traits = better ability survive and leave fertile offspring
Which of the following is responsible for the nearly perfect match in color pattern between a species of praying mantis (an insect) and the leaves on which it rests?
Adaptation FEEDBACK: The color of the praying mantis represents an adaptive trait that leads to higher reproductive fitness because camouflaged insects are less likely to be seen and eaten.
Speciation is caused by Reproductive Isolation
Allopatric Species separated Sympatric Species together Plants Polyploidy Animals - Lake Victoria Cichlids Food; sex
desert
An extremely dry area with little water and few plants
By combining more than 100 years of data, Boyce and his research team noted that the phytoplankton appeared to have declined by approximately 1 percent each year. Consequently, total primary productivity from all phytoplankton in the ocean has decreased as well. How could the primary productivity from phytoplankton theoretically be increased? (Hint: How is NPP typically increased, and which mechanism(s) will work for phytoplankton?)
Availability of nutrients is one factor that has a large impact on primary productivity. Indeed, when the oceans are supplied with limiting nutrients such as nitrogen and iron, algal growth and primary productivity both increase.
Hybrids
Birds that are similar but are primarily in different areas If range overlaps, sometimes they will mate Offspring are then considered a subspecies Evolution, changing habitats, etc. can make it very difficult for scientists to come to a conclusion about certain organisms Polar bears/grizzly bears Grizzlies moving north, polar bears moving south. Able to mate & produce at least female fertile offspring Tigers/Lions = Liger or Tigon Produce offspring but males are sterile, females are not
mutualism
Both organisms benefit from their interactions (alligator and birds; zebra and birds; clown fish and sea anemone)
Some Predicted Consequences of Climate Change Are Now Being Seen
By the end of the century, summer sea ice in the Arctic will disappear, as will many glaciers; sea levels will rise at least 1 meter, and the oceans will be more acidic; rainfall patterns will change, and severe weather will be more common; many species will become extinct.
Which of the following examples indicates a cyclical fluctuation within a population?
Cat populations increase as rats become more abundant and decrease as rats become scarce. FEEDBACK: Cyclical fluctuations occur when the population size of one species is strongly influenced by a second species.
Which of the following is an example of natural selection?
Cheetahs invade a new habitat, chasing down gazelles that live there. The gazelle population becomes faster over time. (When predators eliminate some individuals in a population and leave others behind that then reproduce, the survivors' genes become more common in the population due to natural selection.) Climate change warms a coral reef. A population of reef fish becomes more heat tolerant over time. (When environmental conditions eliminate some individuals in a population and leave others behind that then reproduce, the survivors' genes become more common in the population due to natural selection.)
3 things used to identify/distinguish species
DNA sequence similarity biogeographical information morphology (physical characteristics)
A biologist receives seven new species of live insects from Brazil and is asked to determine their evolutionary relationships. Which method could help the biologist with this task?
DNA sequence similarity is an indication of evolutionary relatedness. Shared anatomical structures often indicate a shared ancestry. Embryos of animals often display traits that are similar to those found in their ancestral species.
Darwin made two main points in The Origin of Species
Descended from ancestral species/organism Descent with modification Process: Natural selection
Kingdom: Animalia
Domain - Eukarya Kingdom - Animalia Multicellular Heterotrophic Grouped based on derived characteristics Phylum - Porifera Phylum - Coelenterata (Cnidaria) Phylum - Ctenophora Phylum - Platyhelminthes Phylum - Aschelminthes (Nemotoda) Annelida Phylum - Arthropoda Phylum - Mollusca Phylum - Echinodermata Phylum - Hemichordata Phylum - Chordata
Which of the following are attributes of evolution?
Evolution can only occur in populations. Genetic changes must occur for evolution to happen.
The highest global primary productivity in oceans is near the equator.
FALSE In marine ecosystems, nutrients are more important than temperature in determining primary productivity. Because the concentration of nutrients in the ocean is highest near the land, coastal areas have the highest primary productivity in oceans.
The founder effect produces new alleles and phenotypes that were not present in the originating population. T/F
FALSE The founder effect describes a process in which a small number of individuals from a population establish a new population, containing only a subset of traits already present in the original population.
food web
Food webs are composed of many food chains that show one species eating another.
coniferous forest
Forest populated by cone-bearing evergreen trees; mostly found in northern latitudes
prezygotic barriers
Geographic isolation Temporal isolation (the mating season for different species may be different) Behavioral (one species may have special mating dances to which another will not respond) Mechanical (the "parts" necessary for mating may not be anatomical matches anymore between two different species) Gametic isolation (lack of appropriate recognition molecules on the gametes allowing them to fuse to form a zygote)
Warming due to climate change has resulted in the loss of permafrost in the tundra, and these areas are converting to wetlands. Do you predict that primary productivity will increase or decrease as a result of this biome change?
INCREASED PRODUCTIVITY The conversion of tundra to wetlands will result in an increase in productivity, as wetlands are one of the most productive biomes.
The State of California started experiencing drought conditions in 2011. The drought has continued and is getting worse, prompting the governor of California to declare a statewide water emergency in 2015. Is it correct to say that this is a change in climate for the state of California? Select all that apply.
No, there are not enough data at this point to support that this is a change in climate for California. No, it is a severe event but has not continued long enough to be considered a change in California's climate.
Do antibiotics create resistant strains of bacteria?
No, to become resistant to antibiotics, individual(s) in a population must randomly mutate, and that mutation, if heritable, causes the bacterial population to become resistant to antibiotics. Bacterial strains become resistant only because individuals in the bacterial population who are already resistant survive and reproduce more than other individuals. Antibiotics do not cause changes in cell membrane proteins, most antibiotics can work on multiple strains and species of bacteria, and antibiotics do not mutate the bacterial DNA to confer resistance. Mutations happen in the presence and absence of antibiotics.
eutherians
Offspring are nourished inside the mother's body through the placenta. Offspring are born in a relatively well-developed state.
Primary productivity on land is largely accomplished by ____, and in the sea, it is largely accomplished by _____. Primary productivity is influenced by the efficiency of _____, or the amount of solar energy acquired by the primary producers. But not all of the energy acquired by primary producers is available for use by consumers, as much of it is lost to _____. The fraction of energy in primary producers that is not used for respiration and maintenance is called ______
Plants; phytoplankton; energy capture; respiration; primary productivity
Which of the following is a good measure of how fast a population is growing?
Population doubling time
Postzygotic Barriers
Postfertilization barriers to reproduction: -Hybrid inviability -EX: sheep crossed with goat embryo embryo dies Hybrid sterility ex: horses x donkeys= mules
coevolution
Process by which two species evolve in response to changes in each other
The Eukarya is grouped into four distinct kingdoms:
Protista: a diverse, single-celled group that includes amoebas and algae Plantae: encompasses all plants Fungi: includes mushrooms, molds, and yeasts Animalia: encompasses all animals, including dinosaurs, birds, and humans
Which of the following factors influences the global patterns of primary productivity in terrestrial ecosystems much more than it does marine ecosystems?
RAINFALL is much more important to terrestrial than marine ecosystems because marine ecosystems are already adapted to their unlimited supply of water.
Stick insects got their common name because of how well they morphologically match their environment, which is typically wood branches. As a type of camouflage, their morphology enables them to avoid predators by appearing to be another stick (or sometimes a leaf) in the bush or tree in which they are living. Stick insects display a wide diversity of colors and shapes, with each species having evolved to closely match its host plant. If Congress were to repeal the Clean Air Act and we reverted to the days of smoggy air with significantly higher particulate matter that caused plants to darken from exposure, which statement would describe the likely evolution of the stick insect populations?
Stick insects that more closely match the darker color of the branches will be more likely to survive and reproduce, with the next generation of stick insects having a higher proportion of darker insects. Changes in environmental conditions can be a strong driver of natural selection, which is the mechanism for biological evolution. Because stick insects are specialized in matching their habitat very closely in color and shape, changes to their habitat, such as the darkening of branches, would significantly affect rates of predation within their populations. Insects that are darker would have the selective advantage of blending in better with their surroundings, making it more likely they will survive and reproduce.
In a forest, there is likely more total energy in the form of herbivore rabbits than carnivore mountain lions.
TRUE Energy is lost with each step up the food chain. Therefore, the amount of energy at each trophic level should be less than that of the trophic level below it.
It is common for as little as 10% of energy contained within on trophic level of a food chain (e.g., insect) to be transferred to the next (e.g., insect-eating bird). T/F
TRUE It is common for only 10% of energy in one trophic level to be transferred to the next; much of the energy is lost as heat or not absorbed by the next trophic level.
NPP (Net primary productivity)-
The amount of new growth that producers generate in a unit area per year. Humans control 30-35 percent of the NPP on land (this affects biodiversity because we are using resources that other species depend on) Net primary productivity relies on four things: sunlight, water, temperature, and the availability of nutrients.
Which of the following scenarios is likely to lead to allopatric speciation?
The formation of the Grand Canyon separates mouse populations on either side. A causeway road is built across a lake, isolating fish populations on either side.
geologic time scale
The history of life can be divided into 12 major geologic time periods, beginning with the Precambrian (4.6 bya to 540 mya) and extending to the Quaternary (2.6 mya to the present).
marine
The largest on the planet, this biome is characterized by salt water.
primary productivity
The primary productivity of an ecosystem is the energy, acquired through photosynthesis over a particular time period, available for the growth and reproduction of producers. Primary productivity is typically determined by estimating the amount of carbon captured during photosynthesis. This can be done by measuring the amount of new biomass produced by the photosynthetic organisms in a given area during a specified period of time.
Which of the following are examples of ecosystems?
a coral reef a temperate grassland
cystic fibrosis
a deletion (Δ signifying deletion) of three nucleotides that results in a loss of the amino acid phenylalanine
Using the definition of natural selection, identify which animal has been "chosen" by the environment to be the "winner."
a female mouse that averages three litters per year with 10 surviving pups in each litter Remember, natural selection is all about reproduction. "In other words, whoever has the most kids wins!" The female mouse with six litters had 24 pups (6 liters x 4 pups), while the female mouse with three litters had 30 (3 litters x 10 pups). The female mouse with five litters had 25 pups (5 litter x 5 pups).
A large island in the Pacific Ocean has two large mountain peaks formed from dormant volcanos. As a result of rising sea levels due to climate change, the island has now become two smaller islands separated by a channel of water. The mountain peaks are in the approximate center of both islands. Which of the following species with populations that have now been separated on each island will likely undergo allopatric speciation if sea levels do not drop again?
a frog species that lives in a narrow range at the lower elevations of the mountain peaks a baboon species that lived throughout the extensive forest of the original island and does not like to swim The key to allopatric speciation is a physical separation that prevents gene flow. In other words, gametes (sperm and eggs) from one population cannot migrate to the other population and promote gene flow. For plants, windblown pollen disperses the sperm (male gamete) and promotes gene flow between otherwise physically separated populations, and the same is true for plants with seeds that float. Animals that have the ability to move across barriers can also maintain gene flow between populations, such as a bird flying from island to island or an iguana swimming from island to island. Species with highly specialized habitats and narrow biogeographic ranges are more likely to undergo a speciation event when a new physical barrier arises.
A genetic bottleneck involves
a large reduction in population size, which can lead to genetic drift.
Climate change is
a large-scale and long-term alteration in Earth's climate, and it includes such phenomena as global warming, change in rainfall patterns, and increased frequency of violent storms.
Evolutionary tree
a model of evolutionary relationships among groups of organisms based similarities and differences in their DNA, physical features, biochemical characteristics, or some combination of these. Maps the relationships between ancestral groups and their descendants Clusters the most closely related groups on neighboring branches
Carbon sink:
a natural or artificial reservoir that absorbs more carbon than it releases Trees in the Amazon absorb approximately 1.5 billion tons of carbon dioxide. This helps slow climate change
Carbon source
a natural or artificial reservoir that releases more carbon than it absorbs After the 2005 drought, the Amazon trees died and rotted. The rainforest stopped absorbing more carbon dioxide than it gave off and released carbon into the atmosphere.
founder effect
a process where a small number of individuals from a population found a new population, containing only a subset of traits that were present in the original population.
A founder effect occurs when
a small group of individuals establishes a new population. In gene flow, alleles move into another pre-existing population.
Loss of a seasonal pool of water causes the extinction of a particular species. This is an example of
an abiotic factor (water) affecting a biotic factor (species)
The type of reproductive isolation represented by this figure is A.) ecological isolation B.) mechanical isolation C.) post-zygotic isolation D.) behavioral isolation FEEDBACK: This figure demonstrates a courtship behavior unique to this species. In behavioral isolation, mating is prevented because of differing courtship displays or other mating behaviors.
behavioral isolation FEEDBACK: This figure demonstrates a courtship behavior unique to this species. In behavioral isolation, mating is prevented because of differing courtship displays or other mating behaviors.
Mutualistic relationships
benefit both species in the relationship.
what is the most important factor in all ecosystems?
biodiversity
factors influencing population growth rate
birth rate (add) deaths (loss) immigration (add) emmigration (loss)
Scientists with the United States National Park Service estimate that food resources within Yellowstone National Park can support a herd of approximately 3,000 bison (also known as buffalo) without damaging the park's ecosystem. This number represents the park's _________ for bison.
carrying capacity
Coevolution has occurred when
changes in one organism, such as a parasite, lead to changes in the traits in another species, such as the host, as a response to the first set of changes.
who created the system of naming plants and animals
charles linnaeus
Aquatic biomes are found in water
classified on the basis of physical and chemical features salt content, nutrients, movement
A parasitic mite that lives on the feathers of certain birds has specially adapted parts that allow it to remain attached. In response, the structure of the birds' feathers changes to cause the mites to be shed regularly. This is considered
coevolution.
Match each species interaction to the correct example. Each answer is used only once.
competition- two grazers, such as rabbits and deer, feeding on the same grass patch (Both species are negatively affected by the other consuming their potential food.) mutualism- the interaction between humans and their intestinal bacteria (The bacteria are fed by the humans' meals and in turn help humans digest some of those foods.) exploitation- an eagle eating a fish (The eagle benefits by getting the nutrients in the fish, but the fish is killed in the process.) commensalism- a bird nesting in a tree (The bird benefits by keeping its eggs away from the ground, but the tree is usually unaffected.)
After wolves were eradicated from Yellowstone National Park, many of the large mammal species living in the park (such as elk and bison) experienced large increases in their populations. However, as their herds grew larger, it was clear there was not enough food to support these large herds. There was an increase in starvation over the winter months, increasing the death rate. What kind of population change is demonstrated by the elk and bison?
density-dependent
This biome has the lowest production on the planet, due to extremely low precipitation levels. Extremely low moisture levels also result in exceedingly high daytime temperatures with plunging nighttime temperatures. Plants in this biome are adapted to the low moisture levels, with most having spines instead of leaves and many storing water in their leaves and stems. Because of the intense daytime heat, most animals in this biome are nocturnal (active at night) and stay in their burrows during the day. This biome encompasses one-third of the Earth's land surface, an area that is increasing annually.
desert
ecology is studied at
different levels (individual, populations, communities, ecosystems, biome, biosphere)
communities
different species that live in the same area and interact with one another
Which of the following would be considered weather?
extreme flooding during a hurricane heavy spring rains and dry summers
Boyce and his research team leveraged Secchi disk data to estimate the average concentration of primary producers in the ocean over the last century. Considering this, determine whether the following statement is true or false. Secchi disk analyses would also be the ideal way to most rapidly and easily monitor current episodes of harmful algal blooms worldwide.
false Boyce and his team resorted to Secchi disk data since the satellite data have only been available for the last decade.
The biosphere includes only living (and no nonliving) components. T/F
false The biosphere does include all of the biological organisms on Earth, but it also includes all of the nonliving factors that affect biological processes.
class amphibia
females Deposit eggs in water and then males fertilize which produce tadpole (larva) First Tetrapods (4 legs on land) Notocord in young, but not in adult (This is a characteristic of all higher vertebrates)
The environment includes both biotic (living) and abiotic (nonliving) components. Which parts of the environment are biotic?
fish bacteria butterflies
Which of the following ecological communities contains the greatest species richness?
five wolves, six foxes, two elk
all evidence we have for evolution comes from the
fossil record. the fossil record is not complete and does not show reproductive success
Are fungi more closely related to plants or to animals?
fungi are more closely related to animals
A tourist brings home a small fish and releases it into a nearby lake. This fish is able to breed with fish already in the lake. The lake population is mainly orange and this fish is white. This is an example of
gene flow
Which of the following cannot occur when a population is in geographic isolation from others of its kind? A.) gene flow B.) mutation C.) natural selection D.) Nonrandom mating
gene flow FEEDBACK: When a population is geographically isolated from others, it means that there can be no flow of genes between the populations involved.
Since the supercontinent Pangaea broke up, millions of species of organisms have been geographically isolated from one another. Which of the following means of evolution have been occurring in those populations on the seven continents since then?
genetic drift natural selection sexual selection mutations In the millions of years since Pangaea separated, all means of evolution have been occurring on all continents, creating genetic divergence between the geographically isolated populations.
Speciation is the process by which one species splits to form two species or more. Which of the following describe the evolution that occurs when there is a physical barrier between two populations and these two populations evolve away from one another? Choose one or more: A.sympatric speciation B.geographic isolation C.allopatric speciation D.ecological isolation
geographic isolation allopatric speciation
Which of the following are results of climate change due to global warming?
glacial retreat species extinction
Kingdom: Fungi
heterotrophic- absorb nutrients grouped based on reproduction Reproduce via spores Can be dormant and will sprout under favorable conditions Fungi do not fossilize well, and much of their evolutionary history is unknown. Scientists have found fossils of terrestrial fungi that are 455-460 million years old.
tropical rain forest
hot, wet biome with year-round humidity; contains Earth's most diverse species of plants and animals
relative species abundance
how common one species is relative to another
postzygotic barrier
hybrid infertility If the hybrid offspring of individuals from two different populations is infertile, gene flow cannot occur between the populations, even though a zygote was produced.
postzygotic barriers
hybrid unviability, hybrid sterility
high abundance
if one species dominates, the community is less diverse
biosphere
includes all the organisms on Earth, together with the physical environments in which they live.
The term "species" describes
individuals living in a group that can mate with each other and produce fertile (able to reproduce) offspring. Hybrids are the result of reproduction by two different species; their offspring can be fertile or infertile (unable to reproduce). A "population" refers to a group of individuals of the same species living in the same general geographic area. "Chimera" refers to an organism made up of genetically distinct cells, named after a figure from Greek mythology that was a fire-breathing monster hybrid.
The biological species concept identifies a species as a group of individuals that
interbreed with one another and produce fertile offspring
exploitative competition
is an indirect interaction between two species that both compete for the same resource. In this case, the elk utilize all the aspen saplings, and other organisms, such as beavers, are harmed by the loss of aspen.
exponential growth curve
j shaped curve constant growth rate no limiting resource if given growth rate, calculate population total
Whenever a particular species has a disproportionately large effect on a community, ecologists refer to that species as a ______ species.
keystone species
Which statement best describes the population growth illustrated by this S-shaped curve?
logistic growth where the population grows exponentially at first and then stabilizes
On average, roughly 10% of the energy at one trophic level is transferred to the next trophic level. Which of the following may describe a possible fate of the other 90% of the energy?
lost as heat; consumed, but not absorbed by the next trophic level; not consumed by the next trophic level, so it remains at current level
high richness
many species are present. the community is more diverse
node
marks the moment in time when an ancestral group split, or diverged, into two separate lineages Represents the most recent common ancestor of the two lineages in question
Several generations into the future, a population of birds currently undergoing stabilizing selection will look
more like the current mean Stabilizing selection shifts the population extremes toward the mean, as individuals near the mean reproduce more than those toward the extremes, creating more individuals clustered around the mean.
aquatic biomes
named after salt content or physical features marine- ocean (salt water), estuaries (ocean meets freshwater), salt marsh freshwater- defined by nutrient content
Nutrients are transferred between organisms and the physical environment in cyclical patterns called ________
nutrient cycles or biogeochemical cycles.
Net primary productivity (NPP) of a system refers to the amount of energy that is
obtained through photosynthesis minus the amount lost through cellular respiration.
competition
occurs when two species share (fight for) a limited resource and the success of one species excludes another (food, shelter, water, mates, territory)
Kingdom: Protista
oldest eukaryotes both autotrophs and heterotrophs single-celled and multi-cellular artificial grouping
Consumers:
organisms that obtain energy by eating all or parts of other organisms or their remains
climate change is caused by
overpopulation and overconsumption
Which of the following resources, used by humans, are produced by the biosphere?
oxygen water wood
Mass extinctions
periods of time during which great numbers of species go extinct fossil record shows there have been 5 mass extinction events
Which of the following is a nutrient that must be recycled within ecosystems?
phosphorus nitrogen
The morphological species concept, on the other hand, identifies a species as a group of individuals that share a set of
physical characteristics
The abiotic portion of an ecosystem is the
physical environment that surrounds the biotic community
allopatric speciation
physically separated (geographically)
Which of the following policies could an official implement to increase the populations of higher trophic level fish in this region of the ocean?
prevent any fishing in these waters (Though this wouldn't meet the needs of human populations that rely on ocean fishes, this would likely lead to an increase in fish populations at higher trophic levels.) lower the catch limits (fewer metric tons allowed) (In general, the trend lines for the graph of trophic levels and fish catch show that lower fish catch levels are correlated with increased populations of higher trophic level organisms.) allow only lower trophic level fish to be caught (Historically, when lower trophic level fish are caught, the populations of higher trophic level fish increase.)
Which of the following is a factor that would influence ecosystems?
rainfall a viral disease a population of rabbits length of day
Which of the following is NOT a barrier that can lead to reproductive isolation between species living in the same geographic region?
random mating
diversity of a community is determined by
relative species abundance and species richness
A limitation of the biological species concept is that this system cannot be applied to species that
reproduce asexually
what causes speciation
reproductive isolation (causes genetic divergence)
Global warming is a
significant increase in the average surface temperature of Earth over decades or more Global warming describes the warming trend in Earth's climate, which increased an average of 0.75°C (33 degrees F) between 1906 and 2005. Most scientists agree global warming is the result of human-caused increases in the concentration of CO2 and other greenhouse gases in the atmosphere. -Not dependent on how sunlight strikes the Earth -Caused by an increase in greenhouse gases that absorb heat that radiates from Earth's surface and prevents it from escaping to space
If the two plants in the range of overlap (bottom picture) interbreed, and their offspring are able to reproduce with each other, then A.) allopatric speciation has occurred B.) sympatric speciation has occurred C.) speciation has not occured D.) the plant populations were not genetically isolated.
speciation has not occured FEEDBACK: Even though the plant populations were geographically isolated by a river, if they are still able to reproduce and create fertile offspring, they still belong to the same species. This means that speciation did not occur.
exploitative (indirect) competition
species compete indirectly for shared resources (ecological niche)
Which of the following actions would lead to a reduction in ecological footprint? Select all that apply.
switching from fossil fuels to solar power biking or walking instead of driving using geothermal heating and cooling instead of traditional heating and air reusing a cloth grocery bag instead of plastic
A tourist carries home a handful of seeds collected during a hiking trip. This species does not exist in the tourist's home area. These seeds germinate in the tourist's home area and establish a new population with traits that are uncommon in the plant's native area. This is an example of
the founder effect.
carrying capacity
the maximum population size that can be sustained in a given habitat.
Fossils
the mineralized remains or impressions of formerly living organisms
most recent common ancestor
the most immediate ancestor that both lineages share
Cyclical fluctuations occur when
the population size of one species is strongly influenced by a second species.
climate
the prevailing weather of a region over relatively long periods of time (30 years or more)
Predation
the preying of one animal on others *Predator-prey relationships are linked -cyclic *Play a large role in health of ecosystem -Apply selective pressure on organisms (natural selection) -Help to keep populations in check -Predators & prey are density dependent factors
population ecology
the study of the number of organisms in a particular place important for solving real-world problems protecting endangered species controlling pest species
gene pool
the sum of all the genetic information carried by all the individuals in a population.
The energy that fuels ecosystems ultimately comes from
the sun
biodiversity
the variety of life in the world or in a particular habitat or ecosystem.
species diversity
the variety of species within a given ecosystem
population doubling time
time it takes a population to double in size (how fast the population grows)
This biome is characterized by warm temperatures, 12 hours of sunlight daily, and either heavy, seasonal rains or daily rain. High rainfall leaches nutrients from soils very quickly, so most nutrients are rapidly recycled and locked up in the vegetation. This biome is dominated by trees, includes some of the most productive regions, and is the most diverse region on Earth.
tropical forest
terrestrial biome below that receives the most rainfall per year
tropical rainforest This is an image of a tropical forest, which receives abundant rainfall, making it able to sustain a high density of trees.
Identify the biome that is found at the poles and mountaintops, where trees are absent or scarce and the vegetation is dominated by low-growing plants like mosses and lichens. Because of the low productivity, very few large animals live in these areas, although rodents provide food for foxes and wolves.
tundra
applications of population biology
understanding the reasons behind a population's growth patterns can provide critical info for monitoring and managing species
Biomes
unique climatic and ecological features of each such region. Have characteristic plant and animal life. may encompass more than one ecosystem
ecosystem diversity
variety of habitats, ecosystems, communities
Which of the following would be considered climate?
warmer average air temperatures since 1910 increases in frequency of flooding in the past century
Which of the following factors influence the primary productivity of an ecosystem?
water nutrients sunlight temperature
Coevolution
when the interaction between two species so strongly influences their survival that they have evolved in tandem An adaptation in one species evolves alongside a complementary adaptation in another species. Examples: Algae and sea fan corals Hummingbirds and flowers
genetic diversity
diversity within and among species
darwins finches is an example of
example of natural selection and adaptive evolution
oligotrophic
poorly fed (few nutrients)
A ___ includes all interacting members of a species.
population
habitat with many predators
(duller colors) Better camouflage would help individuals avoid predation. The camouflaged colors allow the caterpillars to avoid detection from the birds.
Phylum - Chordata
(subphylum vertebrata) - means backbone
what influences climate?
* Incoming solar radiation -The angle at which the sun strikes Earth influences Earth's different climates. *Landscape features -Rain shadow *Wind currents and ocean currents -4 convection cells: In each convection cell, relatively warm, moist air rises, cools, and then releases moisture as rain or snow.
Eukaryotes
*As oxygen in the atmosphere increased, the first single-celled Eukaryotes evolved. *Roughly 650 million years ago, larger, more complex *Eukaryotes evolved. *Dinosaurs appeared about 230 million years ago, during the Triassic period. And they took over the Earth.
The Cretaceous extinction event:
-Occurred about 65 million years ago -Wiped out three-fourths of plant and animal species on Earth, including non-avian dinosaurs -Researchers suspect that a massive comet or asteroid slammed into the Gulf of Mexico: Blocked sunlight around the planet with debris Decreased the ability of plants to photosynthesize As the plants died, so, too, did animals further up the food chain.
Biological diversity, or biodiversity
-The variety of all the world's living things -Interactions of all the living things with each other and the ecosystems they inhabit -Can be described at the level of genes, species, or entire ecosystems
Scientist use the following to identify and distinguish species
-biogeographical information, -DNA sequence similarity - morphology (the form and structure of an organism or any of its parts)
For example, _1__ rival the productivity of tropical rainforests because they trap nutrient-rich sediments and organic matter, while __2__ have much lower productivity and species diversity and are characterized by stagnant, oxygen-poor water.
1 wetlands 2 bogs
Charles Darwin's Theory
1. All species descend from one or a few original types of life. 2. Environments puts pressures on organisms which limits populations growth. (stressors) How It Works: * Those that are best fit survive and are able to reproduce * Therefore their beneficial traits are passed on to their offspring through genes.
A person's ecological footprint depends on four main types of resource use:
1. Carbon footprint, or energy use 2. Food footprint, or the land, energy, and water it takes to grow what we eat and drink 3. Built-up land footprint, which includes building infrastructure (from schools to malls) that support our lifestyle 4. Goods-and-services footprint, which includes your use of everything from home appliances to paper products
Tertiary consumer:
A bird that eats a spider (secondary consumer) that ate a beetle (primary consumer) that ate a plant (producer)
habitat where seeds have very tough shells
A larger, stronger jaw would suit a mouse for eating harder seeds. Stronger beaks allow the birds to more easily crack the nut shells.
Intraspecific competition
Among individuals of the same species
Evolution
Change over time Change in allele frequencies of a gene pool Populations evolve, individuals do not.
Which of the following groups of organisms is most directly responsible for making available the nutrients contained within the bodies of other organisms for recycling in ecosystems?
DECOMPOSERS break down dead bodies of organisms, releasing the nutrients into the ecosystem where they are then available for incorporation into other organisms.
Primary consumers:
Elk eat aspens (producers).
Disruptive Selection
Extreme phenotypes have advantage over intermediate phenotypes.
While communities can be in close proximity and interact with one another, ecosystems are closed and cannot interact with one another.
FALSE An ecosystem can influence other ecosystems in many ways, including the use or production of resources used by other ecosystems.
Class Aves (Birds)
Feathers. High metabolism. A beak with no teeth. A lightweight but strong skeleton. Production of hard-shelled eggs. All birds have wings....but not all birds can fly air cavity
Greenhouse gases
Greenhouse gases: Carbon dioxide (CO2), water vapor (H2O), methane (CH4), and nitrous oxide (N2O) Function much as the walls of a greenhouse or the windows of a car do: they let in sunlight and trap heat Cause the greenhouse effect
Parasitism
Host is hurt while the organism benefits
Commensalism
Host is not harmed but the other organism gains
Transfer of Energy
In a food chain, energy is passed from one link to another. When a herbivore eats, only a fraction of the energy (that it gets from the plant food) becomes new body mass
Why are large predators rare in ecosystems?
Large predators are rare because energy is lost at as it passes through each level. The more trophic levels away from the first that a species is located in a food web, the lower the amount of energy that will be available to it.
Adaptations
Match an organism closely to its environment Are often complex Help the organism accomplish an important function ALL OF THE ABOVE
How We Affect the Evolution of Others
Modify habitat Complete destruction Partial destruction Creates patches Decrease # of individuals Overhunt Remove older, larger individuals Extinction
cladogram
Organisms are grouped together based on their shared derived characteristics (trait modified from the ancestral trait).
Natural Selection
Organisms can change over generations Heritable traits that increase reproduction & survival are passed down
mutations are
RANDOM and RARE
Convergent evolution
Results in organisms that appear very much alike despite vastly dissimilar genetics.
Binomial Nomenclature/Scientific Names
Unique to each organism Uniform when communicating Comes from Carl Linnaeus, "father of taxonomy" 2-part name = binomial Genus - first word of name Species - second word of name
Why must nutrients be recycled in Earth's ecosystems?
Unlike sunlight, nutrients must be recycled because new nutrients are not entering the planet each day.
bottleneck effect
When a small number of individuals from a population survive an event, leaving behind a population with lower genetic diversity than the original population, it is the __________ effect.
clade
a branch on the evolutionary tree A given ancestor and all its descendants make up a clade. Example: Archaeopteryx and all subsequent animals that evolved from it
Global change is
a broad concept, encompassing all types of worldwide environmental change, including large-scale pollution and loss of biodiversity.
silent mutation
a change in DNA, but nothing changes physically
Biological evolution is defined as
a change in the frequencies of inherited traits in a population of organisms over several generations.
Polyploidy
a condition in which an individual gains an extra full set or two (or three) of chromosomes Invariably fatal in people Not lethal, and even advantageous, in plants New plant species can form in a single generation.
resilience
ability of ecosystems to cope with and recover from damage
Sexual selection in a population
can lead to physical differences between the males and females of a species.
The maximum number of individuals that the habitat can support is called the
carrying capacity
____________ evolution results in organisms that appear very much alike despite vastly dissimilar genetics. Cacti found in North American deserts and distantly related plants (euphorbias) found in African and Asian deserts offer an excellent example of this type of evolution.
convergent evolution Convergent evolution results in organisms that appear very much alike despite vastly dissimilar genetics. Cacti found in North American deserts and distantly related plants (euphorbias) found in African and Asian deserts offer an excellent example of this type of evolution. These two types of desert plants have very different genetics, but they look similar and function in a similar manner. In another example, sharks and dolphins are only distantly related (sharks are fish, and dolphins are marine mammals), yet they both evolved for success as predators in the ocean and share common characteristics, such as a streamlined body. When species share characteristics due to convergent evolution and not because of modification by descent from a recent common ancestor, those characteristics are called analogous traits (instead of homologous traits).
omnivores
eat both plants and animals
An association of species living in the same area is referred to as a(n)
ecological community.
sympatric speciation
ecologically separated - example: polypoidy
_______ is the study of interactions between organisms and their environment.
ecology
3 types of mammals
eutherians, marsupials, monotremes
In random mating, organisms are more likely to
exchange genes with many individuals, decreasing the likelihood of genetic divergence and reproductive isolation because they are not being choosy about only mating with certain individuals. All of the other options prevent successful reproduction between populations.
class mammalia
fur, mammary glands, care for young
This biome has higher moisture than deserts but not enough to sustain trees except in areas near rivers and streams. Their dominant vegetation is grasses and forbs (herbaceous plant species). In North America, you would see burrowing rodents such as voles and prairie dogs, which help to aerate the soil and improve growing conditions for the herbaceous vegetation that historically fed large herds of bison. This biome exists in both temperate and tropical latitudes and is frequently subject to wildfires.
grasslands
What group of organisms shares the most recent common ancestor with plants?
green algea
populations
group of the same species living in an area
Biological evolution occurs only in
groups, not individuals, and must occur over multiple generations in order to be observed and measured.
population monitoring
helps document species decline or recovery
Populations evolve, not
individuals
density independent factors
natural disasters, weather, environmntal pollutants
ecosystems can be affected by
natural disturbances, migration, succession, human disturbances, habitat destruction, over-fishing, over-hunting, pollution
process that drives evolution
natural selection Natural selection favors individuals with most desirable characteristics (for that environment) Acts on variation that already exists in a population Most favorable traits get passed down to offspring
population density
number of individuals per unit of an area (divide pop size by area of interest)
herbivores
plant eaters
reproductive barriers
prezygotic and postzygotic
Phylum - Mollusca
primarily aquatic muscular foot for locomotion shell for protection most diverse group in the ocean
Which of the following abiotic factors greatly influences the location of terrestrial biomes, but not marine biomes?
rainfall Differences in precipitation levels on land, such as between a desert and a rain forest, result in very different ecosystems. In the ocean, all biomes are covered in water, so differing levels of precipitation have little effect on its ecosystem.
Biologists use the word _____ to refer to members of a group of organisms that can mate with one another and produce fertile offspring.
species
Ecological footprint is one measure of sustainability; it is
the area of biologically productive land and water that an individual or a population requires in order to produce the resources and absorb the waste.
The biotic portion of an ecosystem refers to
the interacting living organisms
