Clasification And Ecosystems Flashcards
Features of animals
Multicellular , heterotrophs , no cell wall or chloroplasts
Carbohydrate is stored as gylcogen they have nervous coordination
Features of Plants
Multicellular autotrophs (feed themselves ), have chloroplasts vacuole and cell wall made of cellulose , store carbohydrate as Strath, sucrose is transported around the plant
Features of funghi
Both uni and multi cellular
Saprotrophic (extracellukar enzymes are secretes onto food ) no chloroplasts but have cell walls made of chitin
Store carbohydrate as glycogen
Example is yeast and mucor
Body organised into a mycelium made of hyphae which contain nuclei
Mushroom is the sex organ
Features of protoctists
Most are single called organism
E.g algae amobea
Features of bacteria
Single cell organisms which have a loop of DNA . All are surrounded by a cell wall made of peptidoglycan which protects the bacterium and keeps the shape of the cell . Some species have another layer outside this called a slime layer . Some bacteria can swim and are propelled by flagella . Bacteria have plasmids in the cytoplasm which are small circular rings of DNA carting some of the bacterium genes . Some bacteria contain chlorophyll and can photosynthesis .
E.g e.coli salmonella
What do many funghi and bacteria do
They are important decomposes which recycle dead organism and waste Products in the soil
Features of viruses
They are non living parasites that can only reproduce inside living cells . It is composed of a core of genetic material (DNA or rna ) surrounded by a protein coat . A virus enters a host cell and hijacks the hosts genetic machinery to produce more viruses
E.g HIV influenza
What is classification
Putting organism into groups based on shared charchteristics and evolutionary history .
What do ecologists use to identify species
Dichotomous keys
What is a species
Similar behaviour , biochemistry , morphology , can reproduce fertile offspring as in meiosis chromosomes line up and this cannot happen jn cross species so they therefore can’t produce fertile offspring .
What is the scientific name made out of
Genus and species
Genus must be capitalised and the name must be in italics
What is the classification hierarchy
Kingdom , phylum , class , order , family , genus , species
What is an ecosystem
A distinct self supporting system of organism interacting with each other and with a physical environment .
Consist of producers consumer decomposers and a physical environment . The interaction between biotic and abiotic factors in an area
What are producers
Plants which photosynthesise to produce food
What are consumers
Animals that eat plants or other animals
What are decomposes
Decay dead material and help to recycle nutrients
What is the physical environment
Total sum of non biological (non living ) components of the ecosystem
What is a habitat
A place where specific organism live
What is the population
The number of individuals of a particular species found in an ecosystem at anyone time
What is the community
The population of all species found in a particular ecosystem living together
What is a niche
The role of an organism in an ecosystem
Producers
Are the autotrophs like plants they are always at the bottom of the food chain
Consumers
Heterotrophs anything that consumes other organism
What are trophic levels
Different stages in a food chain
What is the top carnivore
Something that nothing eats
What does a food chain tell us
Feeding relationships in an ecosystem
What does a pyramid of number show
Represents the number of organism in each trophic level
What does a pyramid of biomass show
The total dry mass of living matter at each trophic level . These are always in a triangle
Why are they pyramid shaped
Some parts of the grass arent eaten
Some parts aren’t digested
Many are respires to release energy
Only a small fraction of grass material ends up in the rabbit . Similar loses are repeated at each stage in the food chain
Why is it ineffecitent for humans to eat meat
Beacuse the energy has passed through 2 steps by the time it reaches humans . And at each step the amount of available energy has decreased
How much energy is passed on through the food chain
Only 10% which is why food chains never have more than 5 links .
What are the stages of eutrophication
1) farmers add nitrate containing fertilisers to their soil
2) when it rains nitrates dissolve beacuse they are soluble
3) water runs off the field and the nitrates are leached into lakes and streams
4) algae growth increased rapidly - there is an algal bloom
5) plants die beacuse the sunlight can’t reach them and they therefore can’t photosynthesis
6) bacteria decompose the dead plant and reproduce
7) aerobic respiration from the bacteria during decay means the water is anoxic and all life dies
What does denitrifying bacteria do
Uses nitrates as an energy source and converts them into nitrogen gas this reduces the amount of mitiguen in the soil
Why is nitrogen important
All amino acids have nitrogen and therefore all protein and enzymes need nitrogen . All nucleotides contain a nitrogenous base so all DNA requires nitrogen
How is nitrogen taken into the food chain
Nitrogen fixation - converts n2 which is inert due to strong covalent bonds has into a useable form
- amonia
- nitrates
- nitrates
Then assimilation
Plants take up nitrogen and convert it into Amino acids and DNA
Animals eat plants and the ready made amino acid and DNA
What is nitrogen fixation
Nitrogen gas is converted by free living nitrogen fixing bacteria into amoniaco
What is nitrification
Amonia is converted by nitrifying bacteria into nitrite and then nitrate
How else can you obtain nitrogen
Lightning turns 02 +n2 into nitrite. Haber process turns nitrogen into amonia Organic fertiliser ( manure , compost )
How do plants assimilate the nitrates and amonia
Take them up in the roots of the plant and convert them into amino acids and nucleotides . They have long root hair cells to maximise surface area for a greater uptake of nutrients .
What have legumes got
Root modules which have a symbiotic relationship with nitrogen fixing bacteria ( rhizobium ) that exchange amonia to the plant in exchange for carbohydrates . Legumes have lots of protein because of this . Farmers take advantage of theirs by crop rotation
How does organic nitrogen get into the soil
Death or excretion in urea it is the amonified by decomposers
How is carbon fixed
Photosynthesis fixes carbon into atoms in carbohydrates , lipids , proteins and plants
How is carbon passed down
Death or excretion releases carbon atoms in organic compounds decomposers return carbon to the atmosphere as CO2 , if this is not possible the plant or animal material will become fossilised into fossil fuels in the future for combustion
How is carbon given into the air
Respiration releases CO2 and so does combustion
How is carbon passed down a good chain
By feeding and assimilation
What is the water cycle driven by
Heat from the sun which evaporates water from the surface of the oceans lakes and rivers .
What releases water into air
Transpiration and respiration of organisms releases water vapour into air
How does water vapour come down
Clouds rise over mountains and high ground and cool and water condenses to form rain or snow and this falls as precipitation on the earth where it is taken up by animals or plants or eneters rivers and flows to sea to start the cycle again
How do carbon atoms get into humans
Feeding asimmilation , carbon from carbohydrates lipids and proteins
What do carbon decomposers do
Release c02 into atmosphere by respiration
