Biological diversity and ecosystem dynamics. Flashcards
(121 cards)
1
Q
Define habitat
A
The place where an organism lives
2
Q
Define environment
A
An organisms surrounding. All the a biotic an biotic factors.
3
Q
Define Ecosystem
A
A community of organisms that interact with each other and their environment. Can be aquatic or terrestrial.
4
Q
What is the order of organising the environment?
A
Individual > Population > Community > Ecosystem > Biome > Biosphere
5
Q
Define individual
A
A single organism. one animal, plant, fungus or unicellular organism.
6
Q
Define population
A
A group of organisms of the same species.
7
Q
Define Community
A
An ecological grouping of different species that live together and interact.
8
Q
Define Ecosystem
A
A system formed by communities of organisms interacting with one another and their physical surroundings.
9
Q
Define biome
A
A group of communities that have similar structures and habitats extending over a large area.
10
Q
Define biosphere
A
All parts of earth inhabited by living things.
11
Q
What are limiting factors of an ecosystem?
A
All abiotic and biotic factors make it possible for certain organisms to live in an area however it also limits the population growth and ability of certain species to survive.
12
Q
Define the different types of population trends.
A
Stable/balanced- When the population number has stayed approximately the same over a number of years.
Population Explosion- When the population numbers increase dramatically.
13
Q
Name and define the two types of interactions in a an ecosystem.
A
Interspecific- interactions between different species.
Intraspecific- interactions withing the same species.
14
Q
What are the 4 types of relationships within an ecosystem?
A
- Predation
- Competition
- Symbiosis: Mutalism, Commensalism, Parastism
- Allelopathy
15
Q
What is a predation relationship?
A
- When one animal (predator) obtains food by killing another (prey)
- They have an inverse population relationship.
16
Q
What is mutualism?
A
- A relationship which is beneficial for both organisms. E.g Birds pick the knits and mites off the skin of buffalos and rhinos.
- In some cases the relationship is so strong that they can live without each other. Fro e.g. termites eat wood but cannot digest the cellulose, so protozoans do this for them.
16
Q
What is a symbiosis relationship?
A
A relationship between two organisms where at least one benefits.
There are three types Mutalism, commensalism and parasitism.
17
Q
What is commensalism?
A
A relationship where one organism benefits and the other is unaffected.
E.g. The remora rides attached to sharks and other fish for protection and feed of their food remains.
18
Q
What is parasitism?
A
When one organism is used for resources. The parasite benefits and the other is harmed. E.g. ticks, lice, tapeworms.
19
Q
What is a competition relationship?
A
When two or more organism are fighting for the same resource, abiotic or biotic.
20
Q
What is competition population dynamics?
A
When two or more species compete one is better suited and will have a higher population than the rest even when resource and population fluctuates.
21
Q
What is allelopathy?
A
When a plant releases chemicals that can benefits or prevent the growth of neighbouring plants. This can be done by repelling predators and parasites or poisoning competitors. E.g Blackbutt eucalyptus inhibits the growth of its own seeds that fall near the parent plant.
22
Q
What are the ways trophic interaction can be shown?
A
Food chains, Food webs, Biomass, and Energy pyramids.
23
Q
What is biomass?
A
Biomass Is the amount of living materials in an organism or groups of organisms. Producers have the greatest bio mass and this decrease at each trophic level due to the energy being lost at each level.
24
What is a niche?
The part of the ecosystem occupied by an organism. it refers to all the resources that a species uses both biotic and abiotic. No two species can occupy the same niche.
25
What is a trophic Cascade?
There are fundamental nuches, such as decomposers or top predators, without which the entire ecosystem can collapse. E.g. Woves at Yellowstone park or the tasmanian devil.
26
Define disease.
Any process that adversely affects normal functioning of an organism. It can be infectious or non-infectious.
27
What was the top predator till the early 20th century?
The Thylacine (Tasmanian tiger)
28
What are some sampling techniques?
Point sampling
Transect
Quadrant
Capture recapture.
28
What is the difference between distribution and abundance?
Distribution is where an species if found, usually by a place which it has high survival. While abundance is how many member is the species is found in that ecosystem.
29
What are some biotic factors that affect abundance?
Abundance of food, number of competitors, mates available, predators, and number of disease causing organisms.
29
What abiotic factors affect abundance?
Amount of light, Strength of wind, temperature variation, availability of oxygen.
30
What is transect sampling?
A strip is laid across area being studied and organisms along that line is drawn. It is used to determine how the community changes in an area and how commone organisms are.
31
What are the pros and cons of transect sampling?
Pros: time efficient, disturbance to land is minimised.
Cons: rare organisms may be missed, only suitable for sampling stationary or slow moving organisms.
32
How is quadrant sampling done?
A large square is thrown into the area in which you are studying. The amount of organisms withing the square is counted and noted down. The whole area in which you are sampling is measured and then the amount of organisms found in the square is multiplied by the amount of squares that can fit into that area.
33
What are the benefits and disadvantages of using quadrants?
Benefits: A good way to obtain data over a larger area. Disturbance to land is minimised.
Disadvantages: Only suits slow moving or stationary organisms. Time consuming. Organisms not is square will be missed.
34
How does capture recapture work?
Animals are captured marked and the released. After some time a group of population is recaptured and amount of tagged is counted.
34
What are benefits and limitations of capture recapture?
Benefits: Marking of animals should not affect their behaviour or movement.
Limitation: Time consuming and not suitable for slow moving or stationary organisms.
35
What is the formula to calculate abundance with capture recapture?
No. tagged x No. recaptured. Divided by No. tagged in recapture.
35
How is point sampling undergone?
Individual points are chosen on a map and the organisms at those points are counted. It is used to determine the range of organisms that live in an area and how common they are?
36
What are the advantages and disadvantages of point sampling?
Ad: Time efficient and disturbance to environment is minimised
Dis: Rare organisms may be missed.
37
What is natural selection?
The process of adapting to changing conditions and passing on the better suited to survive traits to offspring.
38
What are Darwins 4 Postulates?
1. Individuals within a population have different traits and characteristics.
2. Some of these traits are heritable.
3. More offspring are produced than can survive because os limited resources.
4. Individuals with advantageous traits will survive and reproduce.
39
What are the three types of adaptions?
Structural, Behavioural, and Physiological.
40
What is Physiological adaption?
Adaption of how the organism functions. It mostly relies of structural featues. E.g. Shivering helps to circulate the blood around your body =, which keeps you warm.
40
What is structural adaption?
The physical adaptions.E.g. the gypsy moth is well camouflages to protect it from predators.
41
What are some examples of structural adaptions in plants?
- Reduced leaf size in Spinifex.
- Drip tip on leaf
- 'Buttressing' roots
41
What is Behavioural adaption?
The behaviour of the organism. E.g. A puffer fish puffs up when it is threatened.
42
What are some structural adaptions in animals?
- Thick fur/blubber
- Bright feathers
- Learge ears to increase heat loss.
- Small ears to reduce heat loss
- Webbed feet
- Spines.
42
What are some examples of ;hysiological adaptions in plants?
- Salt exclusion, secretion and accumulation in mangroves.
- Withdrawing of nutrients from leaves in winter.
43
What are examples of Physiological adaptions in animals?
- Camouflage, Evaporative cooling, heat exchange for cooling or heating, deep diving, and hibernation
43
What are the two types of Behavioural adaptions is plants?
Tropism- Growth in response to environmental structure. Towards or away from stimulus.
Nastic movement- Movement of plant tissue in response to the environment. Not in the direction of stimulus.
44
What did Darwin discover about Australian species?
He found that the plants and animals were adapted to the harsh Australian climate. He also found similarities between Australian and European animals with no direct ansestral connection which led him to the idea of 'If organisms have similar habitats, they will adapt to have similar traits.'
44
What are Behavioural adaptations in animals?
- Seeking shelter shade
- Evapourative cooling to lower temperature
- Huddling to maintain body temperature
- Migration
- Urohydrosis- birds pooping on their legs to cool down.
44
What are the three types of topism behaviour?
- Phototropism- growth in repose to sunlight.
- Chemotropism- growth in response to chmeicals
- Thigmotropism- growth in response to touch.
45
What's re the three types of narstic movement?
Thigmonasty- movement in response to touch.
Photonasty- movement in response to sunlight.
Thermonasty- movement in reponse to temperature.
46
What does Darwin and Wallace's Theory of Evolution by Natural selection state?
Evolution occured through the passing on of better suited characteristics to offspring.
47
What did Darwin observe in the Galapougus Islands?
He observed that the environment on every island was different as well as the beaks of the finches evolved to be able to eat the types of foods found on their island. It was later on discovered that one species type came from the island and evolved from each other on the island.
48
What is genetic diversity?
The number of genetic characteristics in a species.
48
Define Species diversity
The measure of different species in a community.
49
How does isolation benefit evolution?
In order for evolution to occur species need to be separated by a physical barrier,e.g. river or splitting of continents. Different mutations will occur within each population and eventually the two isolated populations will not to be able to interbreed, producing a new species. This process is called speciation.
49
What is ecological diversity?
The variation of different ecosystems in a region.
50
Define diversification.
The process by which the diversity of plants or animals develops or is increased within a particular region or groups of organisms.
50
How did earth become diverse?
Early earth conditions made it possible for inorganic molecules to form organic molecules which reacted with each other to form more complex molecules. The molecules formed membranes (first primitive living cells, prokaryotic cells) which developed specialised compartments to carry out different chemical reactions (eukaryotic cells). Cooperation between these cells formed colonial organisms which developed multicellular organisms.
51
Differentiate between micrevolution and macroevolution.
Macroevolution takes place over millions of years and results in a new species being formed. Microeveolution takes place over shorter periods of time and don't generally create a new species however there can be variations, e.g. different dog breeds but belong to the same species or the peppered moths
52
what are examples of physical and chemical changes which may result in evolution?
Physical- temp, availability of water, light, wind, slope and tides.
Chemical- presence of absence of gases, pH, concentration of chemicals.
52
What are the two types of evolution?
Divergent evolution- When a species evolve to have different characteristics due to isolation and new environments.
Convergent- When different species that live in similar environments evolve to have similar characteristics.
52
What is an example of microevolution which resulted in speciation?
Gradual changes of the dog sized ancestor which has evolved to be a horse.
53
What are the 5 types of evidence for evolution?
- Comparative anatomy
- Comparative embryology
- Biochemical analysis
- Biogeography
- Fossils ad paleontology.
54
What is evidence in comparative anatomy?
Different group of organisms often have similar structural features called homologous structures which may be used for different purposes to help organisms survive in their environment. The presence of these structures suggest that organisms all share a common ancestor.
54
What is a vestigial structure?
Evolutionary remnants of body parts that no longer serve a useful function within the population. E.g. our wisdoms, pelvis in whales, appendix in herbivores, coccyx (tail vertebrate)
54
What is an example of comparative anatomy?
1. Pentadactyl limb- A five fingered limb found in many vertebrates and is believed to have been inherited from a common ancestor, possibly the four lobe-finned fish. It consits of a fforesarm bone, two lower arm bones, wrists and five digits.
2. Xylem in plants- similar structures between plant groups suggest a common ancestor. E.g. ferns, conifers andd angiosperm all have vascular tissue including a Xylem.
55
What is comparative embryology?
The study of embryos and their development. All vertebrates in their early stages look the same and become recognisable later on. All vertebrates share the same common features during early stages. These are the gill, tail and notochord (spine). This suggests that all vertebrates have a common ancestor.
56
What is biochemistry?
The study of chemical sequencing in cells. All organisms share the same basic biochemistry, they all: Consist primarily of organic compounds, share a common genetic code of RNA and DNA and rely on enzymes to control chemical reactions. Similarities in the base pairing can be analysed to show how closely related organisms are.
56
What are examples of biogeography?
- The marsupial possums in Australia and south America
- The ostrich in Africa, Emu in Australia and Rhea in South America.
57
What are examples of biochemistry link.
Humans share all but 8 amoino acid sequences with rhesus monkeys but have 125 differences with lampreys which means that humans are more closely related to rhesus monkeys than lampreys.
58
What is biogeography?
The study of the geographic distribution of an organism and the factors that influence these distributions. Biogeogrpahy helps us to understand how the evolution and distribution of species have been effected by geological processes. The basic theory is that each plant or animal species originated from one place and evolved due to isolation.
59
What can palaeontology and fossils tell us?
Palaeontology is the study of fossils. Fossils are the preserved remains, impressions or traces of organisms preserved in ice, coral, amber, rock, or soil. They tell us what kinds of organisms lived in ht epast, what they looked like and where they lived.
60
Differentiate between relative dating and absolute dating.
Relative dating is based on the study of rock strata and the order of appearance of the fossils contained in them.
Absolute dating is based on the rate of decay of radiometric dating.
60
What does the 'law of superposition' state?
The sequence in which the fossils were laid down in rock reflects the order in which they were formed. The oldest layer of sediment is at the bottom and the youngest is at the top.
61
What is the importance of Transition fossils?
They show us the stages inbetween evolution e.g. the transition of vertebrates from ocean to land.
61
Describe the transition fossil Crossopterygian (lobe-fin) fish
1. It is a fish that could absorb oxygen from the air and had bones in its fins so it could drag itself across the ground. it is thought that amphibians evolved from this line. Fish feature: scales, gill, tail
amphibian features: lobe-fins, lungs
Appeared 400mya
62
What are some limitations with fossils?
- Fossil record is incomplete
- Some organisms are more likely to be fossilised because of their body.
- There is a lack of soft bodies fossils and transitional fossils.
- If the fossil is more than 50 000 yrs old then the exact cannot be determined.oubt in age as absolute dating can only date till 50 000 yrs old.
62
Describe the transitional fossil Archaeopteryx.
- Small flying dinosaur
- Appeared in late jurrasic
- Has both reptile and bird features suggesting birds evolved from this
- Reptile feature: long tail, claws, solid bones, teeth
-Bird feature: wish bone, feathers.
63
What happened to Australian megafauna?
They got extinct. Due to changes in climate and the arrival of humans.
63
Describe the dynamics of an eco system.
Ecosystems are dynamics so they are constantly changing. In a stable ecosystem, small changes are balanceed out with no major effect the the environment. Stable ecosytems have higher biodiversity than unstable ones.
64
How are ecosystems maintained?
Stable ecosystems are self regulating. populations are maintained through negative feedback loops. Negative feedback loop works to couteract changes in a system and positive feedback loops aim to enhance the change. E.g when we get hot we sweat but when we are in labour we produce an oxytocin which speeds up an intensifies contraction.
65
How does Aboriginal rock painting help us to determine the environment in the past?
ARP are dated more than 60000 yrs old. They depict megafauna which are now extinct. DNA can be extracted from pigment of paint to determine what fungi and microbes have occured there. Changes in flora are consistent with the drying and warming of the land.
66
What changes in Australia's Enviroenment have occured an is supported by evidence?
Australia's was once a cooler continent with higher rainfall and rainforests.
This is supported by Aboriginal rock paintings, rock structure and formation and ice core drilling.
67
What is a stromatolite?
The oldest type of fossil. They were abundant during early earth but are now localized into a few small areas due to the conditions of Earth. Stromatolites are made from layers of photosynthetic cyanobacteria.
68
What can palaentological evidence tell us?
The appearance of fossils often give clues to the climate and environment at the time. E.g. pollen grains, rock layers, limestone, presence of coal.
68
What can banded iron formations tell us?
periodic deposits turned to stone and are seen as layers section of rock. Red layer of sediment (insoluble iron oxide) shows a change is the presence of oxygen (cyanobacteria). Build up of oxygen killed the cyanobacteria and resulted in a dark layer of sediment.
69
What is the purpose of ice core drilling?
Studying the gases trapped in ice allows us to interpret past environments. Gases, dust, pollen, volcanic dust, radioactive particles may all be retrieved from drilled samples which can be 'radiometrically dated' to determine age.
70
How long ago did Pangea split and what were the two pieces named?
About 160 million years ago.
LAURASIA: North America, Europe and Asia (except India)
GONDWANA: South America, Africa, India, Antartica, Australia.
70
When did Australia move away from Gondwana?
About 45 million years ago and is moving at a rate of 6cm/year.
70
What changes to Australia's environment occured after the split of Pangea?
When Australia was still joined to Antartica about 65 million years ago its climate was cool, wet and much of the country was covered in rainforest however once it split from Antartica about 45 million years ago its climate started to get drier and hotter. As Aus moved northward it began to get warmer, rainforests shrank and sclerophylll and grasslands increased.
71
What changes occured to Australia plants after it split?
Australias two groups Acacias and Eucalyptus both adapted to dry hot climate and spread everywhere. Proteacrea diversified into: Banksia, waratahs, grevilles, hakeas etc.
72
What changes occured to Australias Animlas?
When Australia split it contained three types of Animlas: marsupials, monotremes and placentals.
Placentals died out except for bats, Marsupials diversified ans as it got warmer they spread out to occupy many ecosystems. Australian frogs have developed a lack of dependence on water allowing them to live inland, arid areas.
73
What are the primary threat to biodiversity bu humans?
- Habitat destruction
- Introduction of invasive apecies
- Pollution
- Overexploitation
- Climate change
74
What are the reasons for habitat destruction?
- Agriculture
- Mining
- Logging
- Urbanisation
- Irrigation
- Waster disposal/ landfills
- Outdoor recreation
74
What are introduced species?
Species from another part of the world introduced into a new environment.
A new species will cause disruption in the balance of the ecosystem and can often out compete native species for the same resource.
75
What is an example of an invasive species to Austrlia?
Lantana camara- can grow faster then most native plants and in such densities than it block the sunlight from ground plants.
Prickly pear- native to India, Outcompetes native species for water.
Hooved animals- Introduced in early 18th century. Hooves compact soil as animal is grazing which prevents water from seeping in during rains and plants can't establish a hold in the ground. It increases soil erosion on surface soil and river banks.
75
Define over harvesting
Harvesting a renewable resource such as food, beyond the point that it is unable to replenish the harvested mass.
76
Define Anthropogentic climate change
The accelerated change of climate due to human activities.
76
What are the main human factors causing climate change?
- Inceased carbond dioxide from burning fossil fuels.
- Modern agriculture practises
- Widespread land clearing
77
What are the major impacts of climate change?
- Water security
- Agricultural vulnerablility
- Rising sea levels and the impact upon coastal communities
77
Why are models used in science?
Models are representations of reality. They are simplified ways of explaining or demonstrating a more complicated scientific concept. They may be used to explained how something works, or to predict an outcome.
78
What is a way scientists use models ecologically?
Scientists use models to predict the change to climate, ecosystems and biodiversity to help authorities make decisions about the activity of human populations.
79
What are problems caused by agriculture?
- Soil erosion
- Eutrophication
- Salinity
79
Explain how soil erosion creates a problem fro agriculture.
Soil erosion alters the landscape and can adjust the movement of water. Caused by turning soil, removing vegetation, stock movements, irrigation.
80
Explain how eutrophication causes problems for agriculture?
When fertiliser runs off into waterways it introduces high levels of nutrients such as nitrogen and phosphorus. This allows algae to grow excessively which reduces the quality of water. It can block sunlight, reduce oxygen levels and raise the water temperature.
81
How does Salinity effect agriculture?
Through land clearing and excessive irrigation, the water table is lowered. This increases the concentration of salts in the soil and can kill off species of plants in the area.
82
How can we control Salinisation?
Mulch garden beds, plant salt tolerant plants and times spinkler systems.
83
How can we control soil erosion?
Plant more trees, plant crops on slopes and use drip irrigation instead of flood irrigation.
83
How can we decrease soil erosion?
Minimizing ploughing- sometimes environmentally friendly chemicals can kill weeds without disturbing the top soil.
Re-planting vegetation-this allows the roots of trees etc. to hold soil in place and minimised erosion.
84
How can we control eutrophication?
REduce runoff into stream of nitrogen and phosphorus containing fertilisers and detergents, read labels, and control water runoff.
85
How can we control Land clearing?
Replant deep rooted plants and re-establish ground cover.
85
How can we control Introduced species?
Use quarantine and border control to monitor what comes into the country or use methods like biological or chemical control.
85
How can we control pesticide residues?
Use traps and barriers for plants and genetically modify plants and animals.
86
What is the process of mine rehabilitation?
1. Vegetation, seeds and seedlings must be cleared, stockpiled and cared for so that they can be later used during rehabilitation.
2. Tailings (waste material produced from processing) must be treated and cared for appropriately.
3. When mining is completed, the epit must be refilled with landfill or with water to becomes a dam.
4. The stockpiled soil must the be respread over the area and vegetation slowly introduced in stages.
5. Eventually the mine site is rehabilitated to allow native Animlas and plants to return to the area.
86
Describe the effect of mining on Austrlaias agriculture and name the legislation in place in help reduce it.
Metal mining has a tendency to contaminate and change the chemistry of the land, soil and water, effecting the basis of the local ecosystem. Government legislation now requires rehabilitation methods to be determined prior to commencement of mining.
