Unit B Flashcards
What are the different types of interactions in an ecosystem?
Competition, mating behavior, symbiotic relationships
What is ecology?
The study of relationships organisms have with each other and their environment
What are the types of competition? Explain each one
Intraspecific competition which occurs when species compete with itself for resources
Interspecific competition which occurs when two or more species comepete for resources
What is mating behavior?
Some organisms will exhibit a dance, or meeting call in order to attract a mate
For example, birds of paradise
What are the types of symbiotic relationships? Explain each one
Mutualism, both benefit
Commensalism, one benefits, other is neutral
Parasitism, one benefits and one is harmed
What is an ecosystem?
Regions of the biosphere where biotic and abiotic factors interrelate through the flow of energy and the cycling of matter
What type of energy drives ecosystems?
Solar energy
Explain the boundaries in ecosystems
Some have distinct boundaries (ocean)
Others run into each other (forest and Meadow)
What are all ecosystems made of?
Populations and communities
What is a population?
All the same species living together. They are within the same area and share resources
What is a community?
Different populations living together. Within the same area and share resources
What are Ecotones? What happens to the biodiversity in ecotones?
Eco-tones are areas between ecosystems. They contain the most biodiversity because it’s where most organisms interact
What is a niche?
The role an organism place in the ecosystem
What does a niche consist of?
Place in food web, breeding area, habitat, time of day it’s most active
What do niche’s due to competition?
It reduces competition between species for the same resources
For example, Owls and hawks both hunt mice but in different sections of the forest
What is the biosphere?
The thin layer around the earth consisting of 99% of life. Atmosphere, lithosphere, hydrosphere
What are biomes?
Large geographical regions of the biosphere
What does each biome have?
A specific range of temperature, precipitation, vegetative patterns, adapted organisms
Canada has ______ major terrestrial biomes. What are they?
Four.
Tundra, taiga/Boreal, grassland, temperate deciduous forest
What types of terrestrial ecosystems are there?
Muskey, taiga, grassland, deciduous
Is the amount of light, water temperature, and oxygen levels the same throughout the lake?
No
What are the three main zones of a lake?
Littoral zone, limnetic zone, profundal zone
What is the Litorell zone? Describe its light levels and nutrient levels
Begins at the Lakeshore, extends to the point where plants no longer take root.
It is the shallowest part of the lake
Light is able to penetrate, making this the most productive part of the lake
What is the limnetic zone? What is the most common organism?
Area of Lake in which there is a lot of open water. Plankton are the most common organism in this area
What is the profundal zone? Describe its light levels and nutrient levels. How does this zone get nutrients?
Not usually found in ponds. It has low light levels and is low in nutrients, so less biodiversity. It relies on nutrients falling from the limnetic zone
What is fall turnover?
In fall, surface water temperature cools to 4°C. Since water is most dense at 4°C, it sinks, carrying nutrients and dissolved oxygen. This replenishes the deeper water
What is spring turnover?
Surface water temperature warms to 4°C, and sinks carrying nutrients and dissolved oxygen. This replenishes the deeper water
Why are fall and spring turnover vital?
They supply organisms in the profundal region of lakes with oxygen and nutrients
What are some abiotic factors affecting populations?
Soil, water, temperature, sunlight, gases
How many layers are in soil? Describe each layer
Litter (top layer) made of partially decomposed leaves
Topsoil. Small rock particles mixed with decaying plant and animal matter (humus)
Subsoil. Rock particles and small amount of organic matter
Bedrock (lowest layer) layer of rock
How does soil affect populations?
Different ecosystems have different soil (pH and moisture) Organisms are adapted to specific soil conditions
How does water affect populations?
Water availability determines the distribution of animals. The amount is affected by the amount of precipitation, how long it stays in upper layers of soil, and the amount that collects underneath
How does sunlight vary throughout the world?
Ecosystems that are close to the equator receive the same amount of solar radiation all year. The northern and southern hemisphere don’t receive a constant amount of solar radiation
What are some biotic factors affecting population? Describe each one
Competitors. Compete for same resource or mate
Predators. Organisms that prey
Parasites. Benefit by harming the host
What are some factors affecting aquatic ecosystems?
Temperature, chemical composition, sunlight, water pressure, seasonal variation
What is the chemical environment?
Include salt concentration, amount of dissolved oxygen, pollutants, and naturally occurring minerals
How does temperature and sunlight affect aquatic ecosystems?
Temperature and sunlight very through the year and through the ocean and lake ecosystems
How does water pressure affects aquatic ecosystems?
Water is 800 times denser than air. Deeper water means it is more difficult to survive
How do seasonal variations affect aquatic ecosystems?
Seasonal variations can change the amount of precipitation, wind, sunlight, and variation in currents
In winter, the ice prevents light from penetrating and oxygen from being dissolved in water
And summer, the surface water warms, Cooler water stays at the bottom
What are the three layers created the limnetic zone?
Eplimnion (Warm top layer)
Thermocline (thin band where temp. Drops)
Hypolimnion (low temp.)
What are some factors affecting the size of populations and communities?
Biotic potential, limiting factors, carrying capacity, limits of tolerance
What is biotic potential?
Biotic potential is the number of offspring that a species could produce if resources were limited
What is biotic potential limited by?
Birth potential, capacity for survival, breeding frequency
What is birth potential?
Maximum number of offspring per birth
What is capacity for survival?
Number of offspring that reach reproductive age
What is breeding frequency?
Age of maturity and number of reproductive years
What are limiting factors?
Factors that can prevent populations from reaching their biotic potential
For example, toxins, amount of water and food
What is carrying capacity?
Max number of species that an ecosystem can support
Based on the amount of resources such as food and water
What are limits of tolerance?
Range of abiotic factors an organism can withstand and survive
The more tolerant the species is, the greater its chance of survival
What is the law of minimum?
The nutrient/mineral that is in shorter supply determines if an organism will grow
For example, a plant will not grow if there’s not enough nitrogen in the soil
What other factors can affect the size of populations in an ecosystem?
Density independent factors
Density dependent factors
What are density independent factors
Any factor that affects all members of the population, regardless of the size of the population (floods, climate, fire)
What are density dependent factors
Factors that affect members because there are too many population (Disease, competition for a mate, predation)
How do forests affect the climate conditions in a region?
Forests help to recycle carbon dioxide and water
What layers do forests consist of?
Canopy (mature trees) Sub canopies (young trees and shrubs) Forest floor (Ferns) Soil (grasses and litter) Each layer provides a habitat for many organisms
What does a habitat consist of?
An organisms home, food, shelter/nesting sites, range
Why are forested areas valuable?
They have nutrient rich soil, lots of vegetation, and valuable timber
Why are forests cleared?
Agriculture and residential and industrial development
What are three methods for clearing forests
slash And burn, clearcutting, selective cutting
What is slash and burn?
The complete clearing of the forest by felling and burning the trees
What is clearcutting?
The removal of all trees in an area
What is selective cutting
The harvesting of only certain trees from an area, usually old and desieased
What is harvested timber most often used for?
Pulp and paper and production of hardwood
What is habitat fragmentation?
The habitat becomes divided into sections/fragments. It’s separates organisms from food sources
Habitat fragmentation is a result of clearing forest areas
What’s wrong with clear-cut areas being reforesting with monocultures
Monocultures don’t contain the diversity of the original area, enough resources, and is more susceptible to disease and insect
What is prescribed burn
When fires are deliberately set by Park officials
Fire changes ecosystems and can be used to create and maintain mosaic of different vegetation such as grassland, wetland, and shrub area
What is succession
Changes in plant and animal populations between colonization and final climax community
What is a climax community
Final mature community
What is primary succession
New plants in an area where there were none before
What is secondary succession
A series of changes that occur in an area that was previously colonized
What are the two types of lakes
Oligotrophic. Deep, cold, clear, has no nutrients, little photosynthetic activity
Eutrophic. Shallow, warm, lots of nutrients, many photosynthetic organisms
What is eutrophication
Natural aging process of lakes in which a lake slowly fills in overtime. It takes hundreds of thousands of years as dead plant and animal matter falls, accumulates, and decomposes
How did humans increase eutrophication
Result of water pollution from human waste, fertilizers, temperature increases, and organic compounds
What are biological indicators
Organisms that can be used to indicate the health of the pond/lake
What are chemical indicators
PH, BOD, salinity changes, phosphorus and nitrogen
What is biological oxygen demand (BOD)
Test used to narrow down the causes of low levels of oxygen in the water. It is a measure of the amount of dissolved oxygen needed by bacteria to break down the organic matter In a sample over five days at 20°C
What is taxonomy
The field of biology that classifies organisms
What is binomial nomenclature
2 name system used to name organisms
What to name systems are used for binomial nomenclature
Genus name and species name
What is a genus name
Organisms that have similar morphological characteristics have the same genus name
What is species name
Groups of organisms that have similar physical characteristics and can interbreed to produce fertile offspring
What are the seven levels of classification (taxa)
Kingdom, phylum, class, order, family, genus, species
What does the two name system indicate of an organism?
Similarities in anatomy, embryology, and evolutionary ancestry
Cells of organisms are either ___ or ______
Eukaryotic or prokaryotic
What are eukaryotic cells
Found in plants and animals, have a nucleus, DNA packaged in chromosomes within the nucleus
What are prokaryotic cells
Bacteria, no nucleus, DNA is circular and floats through cytoplasm
What are the six kingdoms
Archaebacteria, eubacteria, protista, fungi, Plantae, animalia
What are Archaebacteria
The oldest bacteria, live in harsh environments
What are eubacteria
Has rigid cell wall made of peptidoglycan
What are Protista
Unicellular organisms, can be autotrophs or heterotrophs
What are fungi
Unicellular or made of tubular filaments, lack chlorophyll, obtain food by secreting digestive enzymes and absorbing the molecules that are released
What are Plantae
Contain chlorophyll, can photosynthesize
What are Animalia
Ingest food, most are motile
What is the dichromatus key
Manual used to classify organisms
What is evolution
Process by which populations of living things change over series of generations
What does evolution attempt to do
Evolution attempts to explain why organisms are so different, yet so similar in molecular structure
How does evolution occur
Through mutations in chromosomes
What is adaptation
Changing to better suit your environment
It does evidence of evolution come from
Fossil record. Fossils provide a record of past life and the evolutionary history of living things can be traced through direct evidence in the rock record. Fossilized remains, impressions and traces or organisms provide scientists with direct physical evidence.
When are fossils formed
When the spaces or skeletal materials of organisms are replaced by minerals
What is paleontology
Study of fossils
What is embryology
The study of organisms in the early stages of development
What are vestigial structures
Body parts that were once used, but now has no function
What are homologous structures
Those which have the same basic structure and same basic pattern of early growth, common ancestor
What are analogous structures
Those with similar functions the different origin and no common ancestor
What is divergent evolution
Similar structures in a species gradually become different because of adaptation to a different environment
What is convergent evolution
Development of similar structures in unrelated species due to adaptation to similar environments
What is DNA
Hereditary material that provides instructions for trait and it determines which traits are passed on
Each DNA molecule contains _____
Genes
What is artificial selection
Plant and animal breeding
What are the four nucleotide bases that DNA is made up from
Adenine, thymine, cytosine, guanine
What is natural selection
The organism decides
What is a theory
An idea intended to explain the occurrence of something
What was Aristotles theory And time period
384–322 BC
All lifeforms can be arranged on a ladder of increasing complexity
What was Carl von Lynn’s theory
What was his time period
1730s
Founder of taxonomy, developed binomial nomenclature, named organisms and classify them according to their characteristics
What was debuffon’s theory
What was his time era
1750s
Propose that a species could change
Used fossil evidence to suggest that all species arose from a common ancestor
What was Malthus’ theory
What was his time era
1798
Proposed that populations tend to increase exponentially until there is too much competition for food, and then the population decreases
What was Lamarck’s theory
What was his time era
1809
Believe that new species were constantly being created by spontaneous generation, that organisms have a force or desire that led them to change for the better
What was Lyell’s theory
What was his time era
1830
Wrote the principle of geology, which greatly influenced Darwin. Believed the earth was older than 6000 years and that slow, continual change was the norm
What was Wallace’s theory
What was his time era
1850s
Published the theory of evolution based on natural selection
How did Darwin start thinking about natural selection
Explore the Galapagos Islands and noticed the variations in the Finch populations
What was Darwin’s theory of natural selection
- Overproduction – number of offspring produced is greater than number that can survive
- Struggle for existence – competition for resources
- Variation – mutations occur in gene pool of all organisms and the best traits are passed on
- Survival of the fittest – individuals with traits that gives them an advantage are able to survive and reproduce better
- Origin of new species – over many generations get cumulation of inherited variation results in the formation of new species
What are inherited variations
Passed on from parent to offspring
Continuous variation
Wide range of expression for example height and eyecolor
Discontinuous variation
Distinct categories with few or no intermediates
For example tongue rolling or earlobe attachment
Acquired variations
Occur because of environmental stimulus. For example learning piano
Mutations
Random changes in DNA
Provide new genetic info
What are the three types of mutations
Neutral, harmful, and beneficial
Neutral mutation
No immediate effect on an organisms fitness
Harmful mutation
Reduces its fitness
Beneficial mutation
Gives organisms a selective advantage
What are the two types of reproduction
Asexual and sexual
Asexual
An identical copies made of the parents DNA
Sexual
Offspring aren’t genetically identical to parents
What is speciation
Formation of new species. Can occur by microevolution or macro evolution
Microevolution
Evolutionary change at the species level
Macro evolution
Evolutionary change about the species level
Allopatric speciation
How most species are formed. Three steps
What are the three steps in allopatric speciation
- A barrier separates populations into isolated groups
- Natural selection occurs on each group independently
- Overtime the differences become so great that if the groups were to reunite, they wouldn’t be sexually compatible anymore
Theory of Gradualism
Belief that speciation occurs slowly
Theory of punctuated equilibrium
Belief that change occurs rapidly but then it is followed by a long period of little or no change this theory has three points
What are the three points of punctuated equilibrium
Species evolve rapidly in evolutionary time
Speciation occurs in small isolated populations
After an initial burst of evolution, species I will adapt to their environment and thus don’t change for a long time
