Biology 1009 Final Exam Study guide questions Flashcards
describes a change in 1 or more heritable characteristics of a population from 1 generation to the next.
Biological evolution
a group of related organisms that share a distinctive form.
Species
diversity in gene frequencies
gene variation
Genetic variation can refer to….
differences between individuals or to differences between populations.
the ultimate source of genetic variation, but mechanisms such as sexual reproduction and genetic drift contribute to it as well.
Mutation
Sources of genetic variations…
random gene mutations, duplications, and horizontal gene transfer
individuals with heritable traits that make them better suited to their native environment tend to flourish and reproduce.
Natural selection
Sources of natural selection
genetic drift, migration, and nonrandom mating may alter allele and genotype frequencies and cause a population to evolve.
Genetic composition and characteristics may change as a result of…
natural selection
Certain traits that factor reproductive success become….
more prevalent in a population over time.
Observations of evolutionary change:
Fossil record, biogeography, convergent evolution, analogous structures, selective breeding, homologies, vestigal structures
provide evidence of evolutionary change in a series of related organisms.
fossil record
study of the geographic distribution of extinct and living species.
Biogeography
2 species from different lineages have independently evolved similar characteristics because they occupy similar environments.
convergent evolution
characteristics have been arisen independently, 2 or more times, because different species have occupied similar types of environments on Earth.
Analogous structures/convergent traits
Programs and procedures designed to modify traits in domesticated species.
selective breeding- (artificial selection)
Underlying cause of phenotypic variation is typically due to different alleles.
selective breeding- (artificial selection)
similarity that occurs due to descent from a common ancestor.
Homologies
such as the set of bones in the forelimbs of vertebrates.
Homologous structures
structures that were functional in the past but no longer have a useful function in modern species)
Vestigial structures
When can homologies be seen
during embryonic development and at the molecular development.
a group of individuals of the same species that occupy the same environment and organisms can interbreed with one another.
Population
Population may change in…
size and geographic location from generation to generation.
As size and location of a population change, so does its …
genetic composition.
all of the alleles for every gene in a given population make up.
Gene pool
Allele frequency:
of copies of a specific allele / the total number of all alleles for that gene in a population
Genotype frequency
of individuals with a given genotype / total number of individuals in a population
2 gametes combine randomly with each other to produce offspring; predicts that allele and genotype frequencies will remain the same, provided that a population is in equilibrium.
Hardy Weinberg equation
To be in equilibrium in the hardy equation…
the population must not be affected by evolutionary mechanisms that can change allele and genotype frequencies. (no natural selection, mutations, migration, has large population and random mating)
Hardy equation listed
p2 + 2pq + q2 = 1
relative likelihood that 1 genotype will contribute to take the gene pool of the next generation compared with other genotypes.
Fitness
what is a measure of reproductive success
Fitness
A. 1 extreme of a phenotypic distribution is favored.
B. 2 or more phenotypes are favored. (population occupies a diverse environment)
C.maintains balanced polymorphism in a population. (Examples of the ways in which balancing selection occurs include heterozygote advantage and negative frequency dependent selection)
D. An intermediate phenotype is favored (highest fitness)
A. Directional selection
B. Disruptive selection
C. Balancing selection
D. Stabilizing selection
changes in allele frequencies due to random chance.
Genetic drift
Derived from the observation that allele frequencies may drift randomly from generations as a matter of choice.
Genetic drift
genetic drift favors either….
elimination (0%) or the fixation (100%) of an allele in a population.
May rapidly alter allele frequencies when the size of a population dramatically decreases.
Genetic drift
much smaller when the sample size is large.
random chance
change in allele frequencies of the resulting populations due to genetic drift.
Population size is reduced and rebounded
Earthquakes, flood, drought, human destruction
Bottleneck Effect
Population size is reduced and rebounded
Earthquakes, flood, drought, human destruction
Bottleneck Effect
occurs when a small group of individuals separates from a larger population and establishes a colony in a new location.
Founded Effect
How does migration affect allele and/or genotype frequencies…
Migration reduces differences in allele frequencies between populations and enhances genetic diversity.
Gene flow occurs when
individuals migrate between populations with different allele frequencies.
a form of nonrandom mating in which genetically related individuals have offspring with each other. (increase the proportion of homozygous relative to heterozygotes)
Inbreeding
affect genotypes but not allele
Nonrandom mating
when individuals with similar phenotypes are more likely to mate. (increase in homozygous, decrease heterozygotes)
Assortative mating
Microevolution vs macroevolution
Microevolution is evolution on the small scale of changes in allele frequencies in a population.
macroevolution is evolution on a larger scale and evolutionary changes that produce new species and groups of species.
The biological species concept can’t be applied to…
species that are extinct or reproduce asexually.
What accounts for the phenotypic differences observed among living organisms?
Differences in phenotype are due to differences in expression of the genotype and differences in environmental factors.
What else may occur in order for a new species to arise?
random mutations acted on by natural selection, interspecies mating, changes in chromosome number and horizontal gene transfer
splitting or diverging of a population into two or more species. This can occur by allopatric speciation or sympatric speciation
Cladogenesis
Whats the most prevalent way for cladogenesis to occur
allopatric speciation
occurs when a population becomes isolated from other populations and evolves into one or more new species.
allopatric speciation
Typically, the isolation may involve a geographic barrier such as an area of land or body of water.
allopatric speciation
occurs when members of a species that are within the same range, diverge into two or more different species even though there are no physical barriers to inbreeding.
Sympatric speciation
4 species concepts…
Biological, evolutionary, ecological, and general lineage.
species are a group of individuals whose members have the potential to interbreed with one another in nature to produce viable, fertile offspring but cannot successfully interbreed with members of other species.
Biological species concept
species should be defined based on the separate evolution of lineages.
Evolutionary species concept
species based on an ecological niche, which is a unique set of habitat resources that a species requires as well as influence on the environment and other species.
Ecological species concept
each species is a population of an independently evolving lineage (each species has evolved from a specific series of ancestors and forms a group of organisms with a particular set of characteristics.
General lineage concept
the mechanisms that prevent interbreeding between different species.
Reproductive isolating mechanism
Prezygotic vs
Postzygotic
Pre- prevent the formation of a zygote.
Post- block the development of a viable/fertile individual after fertilization has taken place.
In sexually reproducing organisms, cladogenesis requires…
gene flow interrupted between 2 or more populations, limiting reproduction between members of those populations.
formation of a new species, is caused by genetic changes in a particular group that make it different from the species from which it was derived.
Speciation
type of genetic change that can cause immediate reproductive isolation.
Polyploidy (2 or more sets of chromosomes)
How can a polyploidy occur?
complete nondisjunction of chromosomes and interspecies breeding.
may produce an allodiploid
Interspecies breeding
key components of climate.
Temperature and precipitation
Temperature changes occur due to…
latitudinal variations in the incoming solar radiation.
More heat is lost in the atmosphere of
higher latitudes because the sun’s rays travel a greater distance.
Temperature __ as the amount of solar radiation ___, temperature __increase near the equator.
increases, increases, does not
Global patterns of circulation/precipitation are influenced by
solar energy
High temps at the equator cause the surface of equatorial air to…
heat up and rise vertically to the atmosphere.
areas of high pressure and are the sites of the worlds hottest deserts because subsiding air is dry.
Subsidence zone
The equatorial flow from both hemispheres meets…
near the equator (ITCZ).
Subsidence zones…
having released all moisture into the equator.
From the centers of subsidence zones, the surface flow ….
splits into a direction towards the poles and toward the equator.
The distributions of major biomes are determined by
temperature
How does the tilt and rotation of the Earth influence weather patterns: (23.5 degree tilt)
- Results in the seasonalities.
- At different times, the solar equator shifts (climate regions may experience warmer/colder or wetter/drier weather)
- Different parts of Earth get the Sun’s direct rays throughout the year.
the wind direction is deflected by the rotation of the Earth; deflects the wind directions East or West.
Coriolis effect
What gives spin to the storm system and is a reason hurricanes spin counterclockwise in the northern hemisphere and clockwise in the southern hemisphere.
Coriolis effect
On mountains, temperature__ with increasing elevation, resulting in __ .
decreases, adiabatic cooling
increasing elevation leads to a
decrease in air temp caused by pressure temp
area where precipitation is less, sheltered by the wind, and drier air descends.
Rainshadow
When air is blown across the earth’s surface and up over mountains, it…
expands because of reduced air pressure.
Why does land heat and cool quicker than sea water?
water has a higher heat specificity.
Ocean currents act as…
pinwheels between continents.
Ocean currents direction…
running clockwise in the ocean basins of the northern hemisphere and counterclockwise in the southern hemisphere.
4 factors influence wave size=
wind speed, fetch, duration, and water depth.
Coastal areas are influenced by
tides caused by the gravitational pull of the moon and sun.
At the equator, oceans are pulled…
toward the moon creating high tides and low tides at higher latitudes.
distinguished by differences in temperature, salinity, oxygen content, depth, current strength, and light availability
Aquatic
classified according to temperature and annual precipitation
Terrestrial
soil conditions can influence biome vegetation, and 1 biome type may grade into another at biome boundaries.
Terrestrial
open ocean, intertidal zone, and coral reef (freshwater habitats are divided into lentic and lotic habitats)
Aquatic
The locations of many fossils and living organisms can be explained by….
evolution in one supercontinent followed by subsequent continental drift
Certain plant and animal life are __ to certain geographic areas of Earth
restricted
Wallace defined the world’s biome to 6 major biogeographic regions=
Neartic, palearctic, neotropical, ethiopian, oreintal, and australian.
__ regions correspond to continents but more exactly to areas bounded by major barriers to dispersal.
Biogeographic
The sun’s rays hit the equator most directly resulting in a
tropical climate.
During summertime in the Northern Hemisphere…
Earth is tilted so that the Northern Hemisphere is angled more directly at the sun. (warmer)
the Southern Hemisphere is angled away from the sun, so….
it receives less direct sunlight and experiences winter.
contain abundant animals, are regularly saturated with water, and are seasonally flooded.
Wetlands
land meets the sea, is exposed and submerged by daily tide cycles, and consists of rocky shores, sandy shores, or mudflats.
intertidal zone
an aquatic biome and a wetland is a freshwater habitat.
intertidal zone
marshes and swamps
Wetlands
In the population growth equation,
the letter “r” is defined as the
capita growth rate
helps determine how populations grow, remain steady, or decline over any time period.
capita growth rate
What does the value of “r” indicate about a population?
If r > 0, then the population is increasing. If r = 0, then the population remains constant with zero population growth. If r < 0, then the population is decreasing.
what conditions would you expect to see exponential growth?
occurs in new or expanding populations when resources are not the limiting factor to population growth. At higher r values, the population grows more rapidly indicating exponential growth.
what conditions would you expect to see logistic growth?
population approaches this carrying capacity in which resources become limited and growth slows.
maximum population size that the given environment can sustain
carrying capacity
As you study two closely related predatory insect species, the two-spot and the three-spot avenger beetles, you notice that each species seeks prey at dawn in areas without the other species. However, where their ranges overlap the two-spot avenger beetle hunts at night and the three-spot hunts in the morning. You have discovered an example of
resource partitioning
when two species with shared resource requirements differentiate their niche from each other so that they can coexist in the same habitat.
resource partitioning
Some coloration patterns can be used to warn predators to avoid certain prey. This coloration is called
Aposematic coloration
occurs when two or more toxic species converge to look the same.
Müllerian mimicry
Each member species of this type of mimicry is…
toxic
In Batesian mimicry what is toxic…
only one species is toxic and the non-toxic species mimics its design.
occurs when one non-toxic or palatable species resembles the toxic or non-palatable species to avoid predation.
Batesian mimicry
The trophic levels of a food chain are the….
primary producers (autotrophs) then come the primary consumers (herbivores) which are then eaten by secondary consumers (carnivores) and then the tertiary consumers (carnivores as well).
The base of the food chain is represented by the
autotrophs who create energy from photosynthesis.
when an environment becomes capable of sustaining life, but the environment has a prior history of sustaining life.
Secondary succession
process by which an ecological community evolves over time.
Succession
occurs due to an environment becoming capable of sustaining life that has never sustained life before.
Primary succession
occur from a volcanic eruption or receding glacier.
Primary succession
can occur from a major disturbance that destroys a community without destroying the soil in the environment
Secondary succession
Differentiate among type I, II, and III survivorship curves:
A. The rate of juveniles is low and most people are lost later in life as they get older; invest much time raising their young; many large mammals and humans.
B. The rate of loss of juveniles is high and the survivorship curve flattens out for those individuals that have avoided early death; insects/plants/fish/marine invertebrates.
C. represents the middle ground, with a fairly uniform death rate over time; includes birds, small mammals, reptiles, and some plants.
A. Type 1
B. Type 3
C. Type 2
affects both species negatively (as both compete over food).
Competition
one sided, detrimental to one species and neutral to the other. (0/-)
Amenualism
both species benefit.
Mutualism
benefits 1 species and is neutral to the other (+/0)
Commensalism
predator feeds on prey and causes rapid death.
Predation
animal feeds on a plant.
Herbivory
parasite establishes a relatively long-term relationship with its host; which may or may not lead to the host’s death.
Parasitism
organism lays eggs in a host and resulting larvae remain in the host, killing it.
Parasitoidism
__ may reduce population densities and stabilize them at equilibrium levels.
Competition
a mortality factor whose influence increases with the density of the population.
Density dependent factor
Positive slope
Density dependent factor
a mortality factor whose influence is not affected by changes in a population size or density; mainly physical factors (drought, freezes, etc)
Density independent factor
Slope equal (straight line)
Density independent factor
Negative slope
Inverse density dependent factors
a mortality factor whose influence decreases with increasing population size.
Inverse density dependent factors
A linear depiction of energy flow with each organism feeding on and deriving energy from the proceeding organism.
Food chain
Feeding relationships with organisms are characterized by an…
unbranched food chain.
Each level of a food chain
trophic level
Whats more complex? Feeding relationships or simple food chains
Feeding relationships
a complex model of interconnected food chains in which there are multiple links among species.
Food web
sum of the number of links between 2 trophic levels involved; tend to be short (5 or less)
Chain length
Key factors that affect species richness are the…
amount of available energy and feeding relationships with organisms.
each colonizing species makes the local environment a little different so that it’s suitable for other species which invade earlier residents. (Continues until the most competitively dominant species have colonized)
Facilitation
early colonists prevent colonization by other species; limited space.
Inhibition
any process can start the succession, but the eventual climax community is reached in a somewhat orderly fashion. (The species that establish themselves and remain, do not change the environment in ways that either facilitate or inhibit colonists. )
Tolerance
harvest light or chemical energy and store that energy in carbon compounds.
Autotrophs
Most include plants, algae, and photosynthetic bacteria
Autotrophs
contain protists, most animals, and some plants
Herbivores
an increase in Earth’s average surface temperature.
Global warming
long term change in earth’s climate or change in climate for a particular region (some areas may get warmer or colder)
Climate change
Greenhouse effect:
solar radiation in the form of short-wave energy passes through the atmosphere to heat the surface of the Earth.
This energy is re-radiated from the Earth’s warmed surface into the atmosphere but in the form of long-wave infrared radiation.
Atmospheric gases absorb much of this infrared energy and radiate it a second time to the Earth’s surface, causing temperatures to rise further.
Without the greenhouse effect, global temps would be
lower than they are.
Greenhouse effect is caused by
water vapor, CO2, CH4, N2O, and CFCs.
as most regions become warmer and a few regions become colder, most plant species cannot easily disperse and move into newly created climatic regions that will be suitable for them.
Alter distribution of species
average level for the surface of 1 or more of the Earth’s oceans.
Sea level rising
With an expected future 2-4 degree C warming, sea levels are expected to rise 50-60 cm due to…
melting of glaciers and thermal water expansion.
In precipitation patterns from global warming, higher temperatures…
increase evaporation and warmer air holds more water vapor.
Increased temperatures will lead to widespread
droughts in desert areas; wet get wetter and dry get drier.
Biogeochemical cycles= movement of chemicals through ecosystems involve what mechanisms?
biological, geological, and chemical transport mechanisms.
Elements required in the greatest amounts by living things…
C,H,O, are P and N.
How are humans affecting the Carbon Cycle?
- burning of fossil fuels are increasingly causing large amounts of CO2 to enter the atmosphere.
- Deforestation contributes to the elevation of atmospheric CO2.
Water Cycle: human activities have altered the water cycle…
- Altering precipitation patterns and causing glaciers to melt.
- Use dams to create reservoirs and impact migration of fish (affects their reproduction).
- built structures that affect the flow of moving bodies of water.
- Aquifers for drinking water removes more water than is put back by rainfall; sinkholes can develop and lakes can dry out.
Process where elevated nutrient levels are used to an overgrowth of algae and the depletion of water oxygen concentration.
Eutrophication
has no gas phase or atmospheric component
Phosphorus Cycle
The phosphorous cycle is what kind of cycle?
local cycle
What’s an effect of the P cycle…
When algae and plants die…
they sink to the bottom where they are decomposed and consume the dissolved oxygen in the water.
This can kill the fish.
tendency of certain chemicals to concentrate in organisms and higher trophic levels in food chains; can cause health and reproductive problems for certain organisms.
Biomagnification
spread naturally and impact native species.
Invasive species
Characteristics of invasive species….
May reproduce rapidly
may not have natural enemies in new habitat
may act as predators and outcompete native species
may compete aggressively for resources
some are lethal pathogens.
Humans kill adult prey at rates up to …
14x higher than predators.
practice in which humans harvest a particular species at a rate that’s unsustainable, based on its natural mortality and capacity for reproduction.
Overexploitation
Effects of overexploitation…
Hunting of animals has been the cause of many extinctions.
humans’ ability to identify valuable species and remove them from their native habitats has led to overexploitation.
human driven process where a natural habitat is altered in a way that prevents it from supporting the species that were originally present.
Habitat destruction
What reduces biodiversity?
Habitat destruction
Primary cause of extinction….
Habitat destruction
deforestation, conversion of habitat to agricultural land, urbanization, strip-mining, quarrying.
Habitat destruction
Freshwater habitats have also suffered from…
dam construction and river channelization.
conversion of forested areas to non forested land; forests allow crops to evolve, future breeding of the crops, rich in plants and medicinal value, and good economic value.
Deforestation
The destruction of habitat to plant agricultural crops and to provide pasture for grazing livestock can create….
soil erosion, flooding, declining soil fertility, silting of rivers, and desertification.
