Term
| Biological evolution (macro-evolution) |
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Definition
| Over billions of years of earth history, evolutionary processes have produced all existing and extinct kinds of plants and animals from a single cell common ancestor. Charles Darwin - descent with modification - passing traits from parent to offspring [image] |
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Term
| How do populations evolve? |
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Definition
| there is a change in the allele frequency in the gene pool. When only certain populations survive natural selection, this can cause some variations of species to go extinct, and other ones to survive. there has been and will continue to be, on average, a (natural) selection of those organisms that have advantageous traits that will lead to the evolution of species. |
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Term
| Distinguish between a gene and it's alleles |
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Definition
| A gene is a portion of DNA that determines a certain trait, an allele is a specific form of a gene. |
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Term
| Who’s work (2 authors) heavily influenced Darwin’s development of natural selection? How did they influence his ideas? |
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Definition
1. Thomas Malthus contended that the human growth curve was geometric, while the human growth curve was only arithmetic
2. Charles Lyell found the formation of Earth's crust took place through countless small changes occurring over vast periods of time, all according to known natural laws (gradualism) |
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Term
| Natural Selection is a mechanism that supposedly explains how populations evolve. Darwin developed this mechanism – describe his view of natural selection |
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Definition
Darwin's theory of evolution took says that evolution takes place by natural selection, which includes 4 factors:
1. The struggle for survival - biological organisms have more offspring than can possibly survive
2. Inherit-ability - biological organisms inherit some of their traits from their ancestors and pass them on to their descendants
3. Variation - the inheritable traits of biological organisms vary, even within the same species
4. Differential fitness - some inheritable traits will be more advantageous than others in the struggle for survival |
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Term
| In Darwin’s view, what is survival of the fittest? |
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Definition
| Only organisms that have traits fit for the conditions to survive will move on |
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Term
| Describe natural selection as seen in the examples with the work on Darwin's finches by the Grants, Kettlewell's experiments with Industrial Melanism, and the guppy populations in Trinidad. Know the details of how these cases are used to support natural selection. |
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Definition
-macroevolution because they don't transcend the boundaries of a single species
-
Darwin's finches on the Galápagos are an example of adaptive radiation
Adaptive radiation:
- The diversification, over evolutionary time, of a species into several different species or subspecies that are typically adapted to different ecological niches (for example, Darwin's finches).
- in adaptive radiation, a species changes to occupy a series of different habitats within a region
- each habitat offers different niches to occupy
- a niche represents how a species interacts both biologically and physically with its environment in order to survive. Different environmental conditions or constraints.
- each species evolves to become adapted to that niche |
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Term
| The Hardy-Weinberg Equilibrium is a mathematical expression that examines allele frequencies in a population. What are the 5 assumptions it is based upon? If an assumption is violated in a population more than likely the population is doing what? Connect this to the 5 agents of evolution. |
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Definition
1. The size of the population is very large or effectively infinite
2. Individuals mate with one another at random
3. There is no mutation
4. There is no immigration or emigration
5. All alleles are replaced equally from generation to generation (natural selection is not occurring)
1. Mutation
2. Migration
3. Genetic drift
4. Natural selection
5. Nonrandom mating - sexual selection |
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Term
| Review genetic mutations. Mutations to the genetic code will have one of three possible outcomes. What are the three possible outcomes? |
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Definition
A gene mutation is a permanent alteration in the DNA sequence that makes up a gene, such that the sequence differs from what is found in most people. The 3 possible outcomes are:
– harmful
– neutral
– beneficial effect on the ability of an individual to function in
the environment |
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Term
| Describe the process of speciation - the three key events required. |
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Definition
Speciation is the evolutionary process of forming new species from pre-existing species. Three steps for one species to give rise to a new species:
1. Isolation of gene pools of populations
2. Evolutionary changes in gene pools of populations
3. Evolutionary reproductive isolation between populations |
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Term
| Distinguish between populations and communities |
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Definition
Population - individuals of the same species that live together
Community - populations of different species that live together in the same place |
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Term
| Describe populations as a(n)...Genetic unit. [gene pool] Biological Species Concept - describe it and describe what is meant by gene flow in relationship to a population and species. What is the gene pool? |
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Definition
| Genetic unit - an interbreeding group of organisms occupying a particular space at a given time |
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Term
| Describe the concept of reproductive isolation or reproductive barriers as it relates to the Biological Species Concept. |
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Definition
Biological Species Concept - groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups
Three steps to give rise to a new species:
1. Isolation of gene pools of populations
2. Evolutionary changes in gene pools of populations
3. Evolution of reproductive isolation between populations |
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Term
| Ecological unit (niche) - Distinguish between Autotroph, heterotroph; producer and consumer. |
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Definition
- Ecological unit - functional role of a population called a niche
- Autotrophs - producers; heterotrophs - consumers |
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Term
| Define the concept of a niche and compare it to a population's habitat |
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Definition
| A habitat defines the interaction of organisms with the other factors, which can be living or non-living, while niche describes how that specific organism is linked with its physical and biological environment |
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Term
| In a generalized ecosystem model, distinguish between biotic and abiotic components; intraspecific vs. interspecific interactions; and examples of each. |
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Definition
- Biotic - living (ex. animals)
- Abiotic - non-living (ex. water, leaves)
- Intraspecific - within the species (individual grass plants in a lawn)
- Interspecific - competition (ex. commensalism between whale and barnacles) |
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Term
| When does competition occur between members of the same species or different species? |
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Definition
| Competition can occur between members of the same species and/or different species when there is a lack of food, living space, resources, etc. |
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Term
| Describe 3 distributions patterns of a population in ecosystem. |
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Definition
| A population may have a uniform, random, or clumped distribution. |
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Term
| What factors determine the distribution of populations in an ecosystem? |
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Definition
| Density dependent factors: competition, predation, parasitism and disease. Density independent factors: temperature, floods, pollution, ect. |
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Term
| Which distribution pattern is connected to fierce competition for resources? |
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Definition
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Term
| What is the age structure of a population? |
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Definition
| Age structure is the proportion of a population in different age classes |
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Term
| What does the population pyramid do? |
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Definition
| Shows the distribution of age groups in a population (three types of curves) |
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Term
| Three types of population pyramids |
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Definition
| Expansive, constructive, stationary |
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Term
| What can we predict about a population using age structure and the population pyramid? |
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Definition
| We can understand what makes up certain populations |
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Term
| Organisms are classified as Type I, Type II, or Type III survivorship curves. Describe the characteristics of each and identify the three types of curves on a graph |
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Definition
Type 1- don't have a lot of offspring, mature to adulthood
Type 2- rate of death and birth is about the same
Type 3- have a lot of offspring, not many mature to adulthood |
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Term
| What determines growth of a population |
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Definition
| Gain in population are due to natality and immigration. Losses in population are due to mortality and emigration. |
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Term
| What is "r" in survivorship curves and how is it determined? |
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Definition
| R is the rate of population increase. It is calculated by using the equation r=b-d (b=birth rate and d=death rate). |
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Term
| Distinguish between a closed population and an open population |
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Definition
| Open populations: the total population is dynamic, with new members leaving and being added over time Closed populations: the members of population are fixed and no new members are added or lost from the group |
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Term
| In closed populations the rate of growth is determined by the difference… |
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Definition
| Between death and birth?... |
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Term
| What is meant by exponential growth? |
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Definition
| Each generation is exponentially greater than the last. |
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Term
| Compare the exponential growth (J shape curve) of a population to logistic growth (S shape curve). |
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Definition
J curve - exponential growth
S curve - Logistic growth |
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Term
| Use the example of the St. Matthew Island reindeer herd as an example to explain population growth and limits on population growth. Why did that population crash? |
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Definition
| Because there was too much in population of deer than there was food to sustain them. |
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Term
| What environmental factors determine the growth rate of a population? |
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Definition
| food, water supply, space, shelter, disease organisms, predators, weather conditions, and natural disasters |
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Term
| Growth for many populations can be represented by the sigmoid or S-shaped curve. This S-shaped graph represents logistic growth. The “plateau” on the logistic curve is called the carrying capacity. Explain this concept. Will the carrying capacity change? Why or why not? |
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Definition
| Environmental limits provide an environmental resistance which acts as a negative feedback to suppress population growth, causing the population to "plateau." This may change over time due to a variety of factors including: food availability, water supply, environmental conditions and living space |
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Term
| Population growth is the result of two opposing factors: Biotic potential and environmental resistance. Explain each. |
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Definition
Biotic potential - the ability of a population of a particular species to propagate under ideal environmental conditions — sufficient food supply, no diseases, and no predators
Environmental resistance- factors that limit the biotic potential of an organism |
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Term
| • The life history or life cycle of an organism or a population of organisms is categorized as r-selected species, K-selected species or somewhere between the two. Compare and contrast these two categories. |
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Definition
R-selection: species that produce many "cheap" offspring and live in unstable environments
K-selection: species that produce few "expensive" offspring and live in stable environments |
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Term
| Explain the generalized ecosystem model from your lecture outline including examples of what each arrow represents. |
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Definition
This model represents how species interact in a system.
Arrows 1,3: Ecosystems exchange materials with the environment
Arrows 2,4: interspecific relationship (competition (-/-), predation (+/-), mutualism, (+/+), commensalism (+/0), and parasitism (+/-))
Arrow 5: intraspecific relationship (Larger, dominant grizzly bears occupying the best fishing spots on a river during the salmon spawning season)
[image] |
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Term
| Describe the terms “open”, “dynamic” and “disturbances” as they relate to an ecosystem. Give examples of disturbances that ecosystems are subject to. |
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Definition
| Ecosystems that are open have both inputs and outputs. Ecosystems are also dynamic in nature, subject to regular micro and macro disturbances, both internal and external.disturbances may include fires, flooding, storms, insect outbreaks and trampling. ... Not only invasive species can have a profound effect on an ecosystem, but also naturally occurring species can cause disturbance by their behavior. |
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Term
| Law of Competitive Exclusion |
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Definition
no two species will occupy the same
niche and compete for exactly the
same resources in the same habitat for very long
-One species will have a competitive
edge and will gain a larger share of
resources.
-Resolved by: Migration, Population drop, Extinction, Shift in feeding habits or behavior
[image] |
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Term
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Definition
Intense competition leads to
resource partitioning – niche
specialization |
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Term
| Predator-prey relationships |
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Definition
| interactions between two species and their consequent effects on each other. In the predator-prey relationship, one species is feeding on the other species. The prey species is the animal being fed on, and the predator is the animal being fed |
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Term
| What role do predators play in the ecosystem? |
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Definition
-Preying most successfully
on the slowest, weakest,
least fit members of their
target population
-Preventing excess
population growth
-Allowing successful traits
to become dominant in
the prey population |
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Term
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Definition
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Term
| Prey strategies for defense |
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Definition
-Camouflage
–Mimicking
–Herding
–Chemical defenses aposematic coloration (makes themselves look less attractive)
-Cryptic coloration (camouflage)
–Shells
–Spines
–Smell |
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Term
| Predator-prey cycle (example) |
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Definition
-Songbirds consume many insects
-Most insects eaten by songbirds consume plants
-Songbirds help to sustain forests
-As songbird numbers decline, damage to forests increases |
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Term
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Definition
two or more kinds of organisms live together in
often elaborate and more or less permanent relationships. Often non-antagonistic |
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Term
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Definition
| symbiosis that is beneficial to both organisms involved |
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Term
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Definition
| an association between two organisms in which one benefits and the other derives neither benefit nor harm |
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Term
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Definition
| a relationship between species, where one organism, the parasite, lives on or in another organism, the host, causing it some harm, and is adapted structurally to this way of life |
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Term
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Definition
| Species richness within a system, relative species abundance, and ecosystem diversity (due to climate) |
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Term
| Species richness moves along a latitudinal gradient |
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Definition
| How much of a species exists in certain areas of the world [image] |
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Term
| Describe a keystone species and provide two examples discussed in class |
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Definition
-Plays a unique and significant role
in their ecosystem even though they may have a low abundance.
-Elimination of the keystone species may alter the structure and function of the community
Ex.: Sea otter, American alligator, Pisaster sea star, Sharks |
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Term
| Explain the concept that Ecosystems are dynamic and open to environmental disturbances. |
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Definition
| For an ecosystem to be dynamic, that means that it is undergoing constant change, which in turn means that it is susceptible to disturbances. |
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Term
| What is succession in an ecosystem? |
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Definition
Ecological succession is the set of
changes in community composition that
occur over time in a new or disturbed
community. Succession is the orderly replacement of one community with another |
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Term
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Definition
| Occurs on bare, lifeless substrates, such as those left behind when a glacier retreats or when a volcanic island emerges or erupts on a mainland |
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Term
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Definition
| This is similar to a primary succession however the soil remains intact and the soil contains a native seed bank. The secondary succession will reach its climax state quicker than primary succession will. The process consists of a disturbance. |
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Term
| Give a full description of what an ecosystem is and its components i.e. differentiate between the abiotic and biotic components |
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Definition
Any area of nature that has living
and non-living components that
are interacting to produce and
exchange materials |
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Term
| There are eight major terrestrial biomes. Identify the factors that determine the type of biomes found in an area. What is a biome in relationship to an ecosystem? |
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Definition
-Tropical rain forests are the richest ecosystems on earth -Savannas are grasslands that have widely spaced trees and seasonal rainfall -Deserts are dry places with sparse vegetation -Chaparral also called scrub forest, are dry with shrubs the dominant vegetation – periodic fires. -Grasslands (also called prairies) occur in temperate areas -Deciduous forests are forests of trees that drop their leaves in the winter
-Coniferous forests: The taiga is a great ring of coniferous trees that extends across vast areas of North America and Asia
-Tundra is open, often boggy, grassland that occurs in the far north beyond the taiga |
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Term
| What is a biome in relationship to an ecosystem? |
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Definition
| Biomes and Ecosystems. Earth's biomes are areas with similar climate, geography, and other conditions as well as similar plants, animals, and other living things. ... In an ecosystem, the plants, animals, and other organisms rely on each other and on the physical environment |
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Term
| List and describe the relationship between two biological processes that are foundational to energy flow through an ecosystem. Which of the two is the key reaction? |
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Definition
| Ecosystems represent a type of “level of life”, “Metabolism and Energy Flow”.Two key processes to energy flow: Photosynthesis(primary production), respiration |
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Term
| Interpret the equation GPP - R = NPP |
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Definition
| As the plant is converting all of its solar energy, some of the energy will be used to do the daily work of the organism. This is R. NPP = net primary productivity. NPP determines or limits the numbers of consumers who can survive on the earth. GPP is the total energy assimilated by primary producers. |
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Term
| What environmental factors determine the level of GPP in an ecosystem? (2 primary factors) |
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Definition
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Term
| What is used to measure the productivity of an ecosystem? |
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Definition
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Term
| What limits the number of consumers in any given ecosystem? |
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Definition
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Term
| Rank the following in order of most productive to least productive ecosystems: Temperate forest, desert, temperate grasslands, tropical forest, tropical savanna (see Topic 08 slides for the answer) |
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Definition
| Tropical forest, temperate forest, Boreal forest, tropical savanna, Temperate grassland, desert |
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Term
| Describe the trophic structure of an ecosystem and a food chain and distinguish between autotroph and heterotroph; producers and consumers. |
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Definition
Autotrophs, herbivores, carnivores.
Autotroph- organism that produces its own energy
Heterotroph- organism that relies on producers for energy
Producers- generate food for them and others
Consumers- only eat other living things/ their products |
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Term
| What is the difference between a grazing food chain and detrital food chain? How are they connected? |
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Definition
Grazing food chain- consists of organisms consuming living producers
Detrital food chain- dead organisms are at the bottom of the food chain |
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Term
| How does a food web differ from a food chain or ecological pyramid? |
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Definition
| A food chain follows one path of energy and materials between species. A food web is more complex and is a whole system of connected food chains. |
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Term
| Using a food web explain two traits of an ecosystem - stability and resilience. |
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Definition
-Resistance to perturbations.
(Stability)
-Ability to bounce back after a
perturbation. (Resilience) |
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Term
| What is meant by the complexity of a food web and how is it related to the stability and resilience of an ecosystem? |
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Definition
The more complex and interconnected a community is, the more stable and
resilient it will be in the face of disturbances or perturbations. |
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Term
| Biomagnification is a consequence of a food web. Explain biomagnification and bioaccumulation and use a pyramid to illustrate the concept. |
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Definition
Biomagnification- when organisms on increasing levels of the food chain acquire toxins from their prey from lower levels of the food chain.
Bioaccumulation- the gradual accumulation of substances, such as pesticides, or other chemicals in an organism. Bioaccumulation occurs when an organism absorbs a substance at a rate faster than that at which the substance is lost by catabolism and excretion[image] |
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Term
| Energy flow in an ecosystem is not _________ but rather it is _______________ |
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Definition
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Term
| Be familiar with the basic story of biomagnifications in "Troubling Treat" on the Centennial Library's ER |
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Definition
| Flying Fox in Guam, FF eats cycid seeds contain a neurotoxin called BMAA, this toxin does not harm the bat. However, when humans eat the FF, they ingest the toxin that greatly increases the chances of getting ALS (lugharigs disease) |
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Term
| Explain what Ecological Pyramids are used to represent. Use the terms below in your explanation: Trophic Level, Biomass, Productivity |
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Definition
Biomass decreases as you move up the ecological pyramid
Productivity (energy received) decreases by 10% as you move up the ecological pyramid |
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Term
| Explain the 10% rule as it relates to an ecological pyramid and sustainability. |
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Definition
| On average 10% of the biomass or the productivity of one trophic level is represented in the biomass at the next higher level |
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Term
| Describe in general a biogeochemical cycle - what is a reservoir regarding the cycle? |
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Definition
Biogeochemical cycle- the flows of energy are different for the different resources,
Light energy- flows in one direction and is released back into the environment as heat (unusable energy) cannot recycle light energy so it needs a continuous supply of energy (sun)
Open community- sun
Closed community- chemicals & nutrients
Nutrient Energy- recycled (cyclical) through the food webs nutrient availability influences the primary production of an ecosystem
Reservoir- the earth & our bodies |
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Term
| Identify what the PCD cycle is and explain how it works. |
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Definition
| PCD cycle- Production Consumption Decomposition Cycle- some nutrients cycle together through this cycle |
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Term
| Why are detritus food webs or chains crucial to a biogeochemical cycle? |
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Definition
Detritus food webs or chains (dead organic matter) are crucial to the biogeochemical cycle because they return to the atmosphere (CO2) or the soil (nutrients)
The nutrients and minerals cycles between the biotic communities and the physical earth |
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Term
| Describe the nitrogen cycle and identify its abiotic reservoir, (Also describe the terms associated with the cycle). Be familiar with the diagrams in the slides related to the cycle. |
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Definition
Nitrogen cycle- bacteria is KEY
-called nitrogen "fixing"
-can be done ATMOSPHERICALLY or BIOLOGICALLY (often via mutualistic bacteria)
-atmospherically N2 + 3O2 à 2NO3 (nitrate)
-biologically 2N2 + 6H2O à 4NH3 + 3O2
-other bacteria can convert NH3 to NO3 via INTRAFICATION, both are taken up by plants and used for protein
-returns N2 back into atmosphere via dentrification
-done by decomposition of organic material by bacterial
-agricultural relevance... trying to efficiently provide food- with the herbicides and cultivation... "messing" with natural process of selection and weed invasion, nutrients cycle often broken so fertilizers often require to supply things like nitrogen
-Development of monoculture
Abiotic reservoir- Earth & soil |
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