Chapter 5 Flashcards
Ecology
Warmer climate =
fewer CO2 bubbles in the ice
Why are ice cores analyzed?
to find the number of bubbles + analyze the gas trapped inside the bubbles
What can we read from the graphs?
- Significant temperature changes
- Rapid changes -> the climate may be quite sensitive
- Lens variable temperature the last 100 000years
- The graphs indicate a strong correlation between CO2 content in the air and temperature
Correlation
vary at the same time
Causation
one thing is the reason why something else is happening
Early increases in CO2 levels were due to…
volcanic eruptions and weathering of chalk and limestone rocks
What is the biggest reason to the increased CO2 level
human activity
Greenhouse gases
gases in the atmosphere that absorb IR-radiation
Gases that have naturally occurins
H20, CO2, CH4
Gases that is due to human contribution only
N0, CFC
GWP
global warming potential
- tries to provide a simple measure of the relative radiators effects of the different greenhouse gases
The precautionary principle
If the effects of a human-induced change would be very large, perhaps catastrophic, those responsible for change must prove that it will not do harm before proceeding
Consequences of the precautionary principle
- melt-down of ice
- warning of seawater
- permanent flooding
- failure of algal photosynthesis
- destruction of forests
- interruption of ocean current system
Actions of the precautionary principle
- conserve fossil fuels stocks
- nuclear power sources
- renewable sources
- bioful sources
- reduce transport
- design well-insulated houses
- terminate the destruction of forests
Outline the counsequences of a global temperature rise on arctic ecosystems
Doubling of atmosphere CO2 –> increase in the active layer of permafrost and a disappearance of most of the ice-rich discontinuous permafrost.
Disapperance of discontinuous permafrost –> -erosion, -change of hydrologic processes, -release of CO2 + CH4 to the atmosphere.
Population
group of organisms of the same species who live in the same area at the same time.
natalaty
offspring are produced and added to a population
mortality
individuals die
immigration
individuals move into the area
emigration
individuals move out of the area
overall population change
(natalaty+immigration) - (mortality+emigration)
lag phase
little or no cell multiplication (natalaty), a period of adaption to conditions
Exponential growth
population increases exponentially, a period of no constraints on growth. Adequate nutrients are available and little accumulation of waste products has occurred. High natalaty rate, and little or no death of cells (mortality).
Carrying capacity
the maximum population size that can be supported by the environment over time
list 3 factors that set limits to population increase
- shortage
- more predators
- more diseases or parasites
all of these become more intense as population size increases = density - dependent factors
Define evolution
Evolution is the cumulative change in the heritable characteristics of a population
Fossil records
- fossilization is an extremely rare, chance event
- most fossils remain burried
- exposed fossils are mostly overlooked and destroyed
- fossils may be dated using C14 or K40 radiocarbon dating
Fossil forms
- petrification-organic matter is replaced by mineral ions
- mould-organic matter decays, and the space left works as a mould and is filled by mineral matter
- trace-impression of a form is preserved in layers that harden. ex. footprint
- preservation- of intact whole organisms, ex. in amber
selective breeding
- used to ‘‘create’’ all the plants and animals used by humans from wild ancestor organisms
- the most useful varieties of organisms in one generation is used to parent the next generation
- result = deliberate genetic change in the population by repeating the human controlled selection process for generations
homologous structures
- groups of related organisms often show similar underlying organisation of f.ex. limb skeleton, although they have adapted to different habitats or lifestyles
- similar organisation = homologous structures
- most likely explanation is a common ancestor
In a stable population…
only one breeding pair may result from each breeding event - all other offspring are casualties of the ‘‘struggle’’ to survive
Population size is naturally limited by environmental factors
- space
- light
- availability of food
- diseases
Never-ending competition for resources results in
the majority of organisms failing to survive and reproduce
gamete formation
random assortment of maternal and paternal chromosomes in meiosis
crossing over segments of individual maternal and paternal homologous chromosomes
results in new combinations of genes on chromosomes
Random fusion of male and female
gametes in sexual reproduction
Natural selection operates to
determine the survivors and the genes that are passed on to the next generation
this may eventually lead to
the formation of new varieties and ultimately new species
Explain 2 examples of evolution in response environmental change; one must be antibiotic resistance in bacteria
- Charles Darwin travelled to the isolated Galapagos Islands on the ship Beagle
- On the islands he found finches with different beaks adapted to eating different kinds of food
- he reasoned that these birds most likely shared a common ancestor
- Geographical separation and different food choices had turned one ancestor into several species with different beak shapes over generations = evolution
Outline the binomial system of nomenclature
- Important to have an international system- so observers know that they are talking about the same organism
- Binomial system = ‘‘a two part name’’
- All binomial names consists of two latin words
- Rattus norwegicus
Rattus (genus name) norwegicus (species name)
Homo erectus
'’The upright man’’ 2-1 million years ago
Homo habilis
'’the handy man’’ 2.2-1.6 million years ago
Homo sapiens
us
18th century:
organisms belonges into either Animelia or plantae
King Philip Came Over For Green Soup
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species
Kingdom
Plantae (plants) / Animalia (animals)
Phylum
Tracheophyta (vascular plants) / Chordata (chorda tes)
Class
Angiospermae (flowering plants)/ aves (birds)
Order
Rosales (roses and their allies)/ passeriformes (songbirds)
Family
Rosacea / parulidae (wood warblers)
Genus
Rosa / dendroica
Species
Rosa gallica / dendroica fusca
Taxonomy
the science of classification
Biological classification
invention of biologists based on the best available science at the time
Aim of classification
to use as many characteristics as possible in placing similar organisms together and dissimilar ones apart
Define species
a group of organisms that can interbreed and reproduce fertile offspring
Define habitat
the place/environment where an organism normally lives or the location of a living organism
Define population
all the members of a species in a certain area at the same time
Define community
all of the populations living and interacting in an area
Define Ecosystem
a community and its abiotic (non-living) environment
or a community and its physical environment and the interactions between them.
Biotic component
all living organisms
Abiotic component
non-living variables, -CO2, temperature, wind, light
2 important features in ecosystems
- Largely self-contained –> nutrients are recycled
- An interactive system: types of organisms in an ecosystem (decided by the physical environment, physical environment is changed by the organisms living there)
Ecology
The study of living organisms in their environment
Autotroph
- an organism that synthesizes its organic molecules from simple inorganic substances
Ex. a plant
Plants do photosynthesis: 6CO2 + 6H2O + light energy -> C6H12O6 + 6O2
(6CO2+6H2O) = simple inorganic compounds (C6H12O6) = organic molecule (lot of carbon)
Heterotroph
- an organism that obtains organic molecules from other organisms
- Animals and any other organism incapable of making C6H12O6 from inorganic substances
- -> need to obtain sugurs by eating and digesting other organisms.
- Cell respiration
- all depend on plants directly or indirectly
- all consumers
Consumer
- an organism that ingests other organic matter that is living or recently killed
- always heterotrophs
Detritivores
an organism that ingest non-living organic matter
- heterotrophs that feed and decompose dead organic matter (kaffedyr)
Saprotroph
an organism that lives on or in non-living organic matter, secreting digestive enzymes into it and absorbing the products of digestion
- fungi, mould
Example of food chain
grass - sheep - wolf
sea weed - shrimps - fish - shark
Food web
- built of food chains which contain members belonging to more than one food chain.
- consists of interconnecting food chains
Define trophic level
feeding level/ position an organism occupies in a food chain
Deduce trophic lever of organisms in a food chain and a food web
- Producer
- Primary consumer
- Secondary consumer
- Tertiary consumer
- Quaternary consumer
- Quintinary consumer
Explain the energy flow in a food chain
- Energy is transferred between each trophic level
- Green plants transfer light energy into chemical energy in sugars through photosynthesis
- Energy is transferred every time a plant is eaten by a herbivore
- When a plant dies, the remaining energy passes on to detritivores and saprotrophs
State that energy transformation are never 100% efficient
The only energy transferred from one step to the next is metabolites (Carbohydrates, proteins, fats) used in growth and development of the plant/animal -> 10% of the energy is transferred
Ecological pyramids =
- 3 kinds used to analyze ecosystems
- Pyramids of numbers
- Pyramids of energy
- Pyramids of biomass
Energy is lost when
- Some organisms die before they are eaten by an organism on the next trophic level
- Some parts of organisms are not eaten
- Some parts of organisms are indigestible
- Much of the energy absorbed by an organism is released in cell respiration
Energy is only available for the next trophic level if
it remains as chemical energy in the growth of the organism absorbing it.
Explain that energy enters and leaves ecosystems, but nutrients must be recycled
Nutrients must be recycled because many are available in limited amounts.
Decomposers release nutrients from dead organisms.
Nutrients released can then be reabsorbed by plants. (Biogeochemical cycle)
State that saprotrophic bacteria and fungi (decomposers) recycle nutrients
Energy is constantly arriving from the sun, passing through living organisms, and ultimately leaving as heat. Matter cycle between living and non-living system between living enters and none leaves.
