Topic 5: On the Wild Side Flashcards
1
Q
What is the definition on an ecosystem?
A
A community and its interactions with the non living parts of its habitat.
2
Q
What is the definitions of a community?
A
All of the populations in a habitat or area at a given point in time.
3
Q
What is the definition of a population?
A
All the organisms of one species in a habitat or area, at a given point in time.
4
Q
What is the definitions of a habitat?
A
The area where an organism lives.
5
Q
What is a biotic factors and examples?
A
Living environmental factors that influence the populations within their communities.
E.g. interspecific competition and parasitism.
6
Q
What is an abiotic and examples?
A
Non-living physical and chemical factors that influence populations within their community.
E.g. light intensity, temperature, humidity and soil/water pH.
7
Q
How do biotic factors control the number and distribution of organisms in a habitat?
A
Biotic factors have drastic effect on the number and distribution of organism. Any effect on these factors have a direct impact on population density and distribution.
E.g. food availability - more food means organism have a higher chance of surviving and reproducing meaning there population increase. Also organism tend to live near and around constant food sources (rivers)
8
Q
How does abiotic factor effectthe distribution and abundance of organisms in a habitat?
A
Any effect to abiotic factors doesn’t directly relate to the size of the community. They always affect the same proportion of the community.
E.g. light intensity affect the rate of photosynthesis of plants more light means increased plant growth.
9
Q
What is the definition of niche?
A
The role of a species within its habitat.
E.g. what it ears and what species depends on it for food.
10
Q
How does the concept of niche effect the abundance of organisms in a habitat?
A
If two species occupy a similar niche within a habitat, they will be competing with each other causing their populations to become smaller and abundance to therefor be lower.
11
Q
How does the concept of niche impact the distribution of organisms in a habitat?
A
- Species can only survive in habitat to which they are well adapted to the biotic and abiotic condition. If they are not they will move to a more suitable location and distribution will change.
- species will only be found where the abiotic factors are favourable as unfavourable conditions will hinder an organism ability to reproduce and survive.
12
Q
What is the definition of carrying capacity?
A
The maximum population size that an ecosystem can support.
13
Q
What is the definition of succession?
A
A sequence of changes in a community, over a period of time.
14
Q
What is primary succession?
A
The process that occurs when newly formed or newly exposed land is inhabited by an increasing number of specie.
- magma cooling and forming newly exposed rock
- glacial retreat exposing bare rock
15
Q
What the are stages of succession.
A
- Pioneer species will colonise the land. (As they are specially adapted to cope with the harsh conditions xerophytic and halophytic)
- Pioneer species will improve the abiotic conditions (stabilise soil, add humus)
- The less hostile conditions been other organisms will colonise the land. (Further improving conditions, helping soil retain more water)
- As conditions improve more specie will colonise which influence completions and affecting the abundance and distribution of previous organism.
- Newer species will continue to outcompete the previous species until the final community in reached. (Climax community)
16
Q
What is a climax community?
A
The final community in a succession, which is self sustaining, stable and dominated by one or several species.
17
Q
What is secondary succession?
A
Recolonisation of an ecosystem that has been cleared or damaged, meaning that there are remnants form previous communities.
18
Q
How can humans prevent succession?
A
Human activity often prevent or irrupt the process of succession stopping a climax community from developing.
- regular mowing prevents woody plant form establishing
- grading activity of livestock can prevent new plants establishing
19
Q
What is photosynthesis?
A
The process by which light energy is absorbed and used to break down water molecules. This produces oxygen and hydrogen (break down of water molecules) which is combined with CO2 to produce glucose and releasing oxygen.
6H20 + 6CO2 + light energy —> C6H12O6 + 6O2
20
Q
Why is ATP energy needed?
A
Organism need tap energy to maintain their cells and stay alive
- building new molecule from products of digestion
- Move substances across cell membrane in active transport
- muscle contractions
- conduction of nerve impulses
21
Q
What is ATP?
A
adenosine triphosphate is used to trade and supply energy within cells.
22
Q
How is ATP formed?
A
ATP is produced during respiration by the addition of inorganic phosphate to ADP.
ADP + P —> ATP
This reaction is catalysts by the enzyme ATP synthase (stored in thylakoid membrane)
23
Q
How does ATP produce energy to be used in biological processes (and catalyst)?
A
ATP is broken down by hydrolysis. This is the process where water is used to break down ATP into ADP and an inorganic phosphate. This process releases energy which is then used for biological processes.
ATP —> ADP + P
Catalysed by ATPase
24
Q
Where does the light dependent reaction take place?
A
The light dependent reaction relies on direct light meaning it takes place across the thylakoid membrane within the chloroplast.
25
Why does the light dependent reaction need light?
Light energy enables the splitting of water molecule in a reaction (photolysis) producing
- 2 hydrogen ions (protons)
- 2 electrons
- one atom of oxygen
The protons and hydrogen ions are used during the reaction while oxygen is given off as a waste product.
26
What is the steps of the light dependent reaction in non cyclic photophosphorylation?
1. Light energy is absorbed by chlorophyll pigments in the photosystems.
2. Light energy excites the electrons in the photosystems (moves them to a higher energy level)
3. Excited electrons move along the electron transport chain, releasing energy to synthesis ATP.
4. Photolysis of water produces oxygen, electrons and H+. The electrons are used to replace the ones lost in chlorophyll. These H+ ions produced accumulate in the thylakoid membrane and oxygen is released into the atmosphere.
5. Photophosphorylation of ADP produces ATP. (light energy released from excited electron as they move done electron transport chain used to combine ADP and P)
6. Reduction of NADP to from reduced NADP (NADPH) in PSI.
* NADPH and ATP produced passes to the light independent reactions.
27
What is NADP?
NADP is a coenzyme and its role is to transfer hydrogen form one molecule to another. It gains hydrogen and becomes reduced. It can reduce other molecules by receiving hydrogen and oxidise molecules by receiving hydrogen.
28
What is cyclic photophosphorylation?
1. Light hits PSI
2. Electron are excited to a higher energy level and leave the photosystem
3. The excited electrons pass along the electron transport chain, releasing energy (drives chemiosmosis).
5. energy used for ADP + Pi --> ATP
4. At the end of electron transport chain the electron rejoin PSI in a complete cycle
* the ATP produced enters light in-dependent reaction
29
What is the light-independent reaction?
The light independent reaction (Calvin cycle) it produces complex organic molecules (starch and cellulose) and get energy from ATP and NADPH form light dependent reaction. It is often referred to as carbon fixation as its is the reduction of canon dioxide using the products form light dependent reaction.
30
Where does the light-interdependent (Calvin cycle) take place?
Does not rely on direct light take place in the stroma within the chloroplast.
31
What are the basic three steps of the Calvin cycle?
1. Carbon dioxide is combined with ribulose bisphosphate (RuBP) a 5 carbon compound, yielding two molecules of glycerate 3 phosphate (GP), a 3 carbon compound.
2. GP is reduced to GALP another 3 carbon compound
3. RuBP is regenerated from GALP in reactions that use ATP
32
What are the detailed steps of the Calvin cycle (light independent reaction)?
1. CO2 enters the plant through the stomata and diffuses into the stroma.
2. The CO2 is fixed with RuBP (a 5 carbon compound) producing and unstable 6 carbon compound.
3. This breaks down into two 3 carbon compounds called GP. (catalyst by enzyme RUBISCO)
4. Energy from ATP and hydrogen form NADPH are used to reduce the 2 molecules of GP into two 3 carbon compound called GALP.
5. Some of the carbons in GALP go towards the production of useful organic molecule such as glucose
6. The rest remain in the Calvin cycle to allow the regeneration of RuBP which requires ATP (5 out of the 6 carbons are used to regenerated RuBP)
33
How is glucose produced by photosynthesis used to form other organic compounds?
The intermediate molecules of Calvin cycle GP and GALP produce
- GP is used to produce amino acids (polypeptides) and fatty acids (triglycerides and phospholipids)
- GALP is used to produce hexose sugar (glucose), glycerol (used in triglycerides and phospholipids p) and nucleic acids (DNA and RNA)
34
What is a chloroplast?
Organelles in plant cells where photosynthesis occurs
35
What is the structure of chloroplast?
Chloroplast is surrounded by a double membrane (chloroplast envelope) which is filled with fluid (stroma). Within the chloroplast a separate system of membrane ps are found consisting of a series of thylakoids. Several component are embedded in the thylakoids membranes ATP synthase and pigments.
36
What is the chloroplast envelope and how is it related to its function?
The chloroplast envelopes is a double membrane which enclosed the chloroplast. It contains transport proteins in the inner membrane to control the flow of molecule between stroma and cytoplasm.
37
What is the stroma?
A fluid like substance found in the inner membrane surrounding the thylakoid membrane contains enzymes. It is the site if the light independent reaction of photosynthesis (Calvin cycle).
38
What is the thylakoid membrane?
Surrounds the thylakoids and is the site of the light dependent reaction of photosynthesis. It contains photosystems and the necessary enzymes associated with photosynthesis and space for accumulations of hydrogen ions.
39
What are the structure and function of photosystems?
There are two type of photosystems both found in the thylakoid membrane. Each photosystems absorbs light of a different wavelength maximising light absorption.
40
What are the structure and function of grana?
The grana are stacks of thylakoids that are connected to the thylakoid membrane. It provides a large surface area to maximise the number of photosystems and allow maximum light absorption.
41
What is gross primary productivity?
The rate at which chemical energy is converted into carbohydrates during photosynthesis.
42
What is the net primary productivity?
The total quantity of energy stored in the biomass of a group if producers, in an ecosystem at a given point in time - respiratory losses. This is the total quantity of energy that is available for growth and consumers in higher trophies
43
How do you calculate the net primary productivity?
NPP = GPP - R
44
What is plant respiratory loss?
The total quantity of energy that is lost from the biomass of producers via respiration in the form of heat.
45
How is energy transferred through a food chain?
1. Plants convert light energy into chemical energy stored in biological molecules
2. Chemical energy stored in the plants biomass is passed onto a primary consumer when the plant is ingested
3. Primary consumer uses the energy for respiration of to build up biomass
4. Primary consumer ingested by secondary consumes and so on
5. When an organism dries the chemical energy stored in its biomass is decomposed by detritivores (bacteria and fungi)
46
What are the main energy losses in a food chain
- energy loss via decomposition
- energy loss via uneaten and inedible parts of an organism
- energy loss via respiration in the form of heat
- energy loss via undigested food such as animals furs which is excreted in faeces.
- energy loss via excretion of waste products (urea)
47
What is net production?
The total quantity of energy stored in the biomass or an organism, minus energy loss via respiration, faeces and urine.
48
How can efficiency of energy and biomass be calculated?
Efficiency = energy after transfer / energy before the transfer x 100
49
What are the types of evidence of climate change?
- records of atmospheric carbon dioxide levels
- records of average global temperatures
- records of changing plant communities gained form sampling of pollen grains preserved in peat bogs over time
- dendrochronology (rings in tree trunks)
50
How can atmospheric carbon dioxide levels be used as evidence of climate change?
Atmospheric carbon dioxide levels have fluctuated over time due to events such as volcanic eruption ect. However since the industrial revolution atmospheric carbon dioxide levels have significantly risen to their highest in earths history.
Prior to industrialisation levels around 300 ppm now over 400 ppm
Data shows a correlation between changing atmospheric carbon dioxide and temperature
51
How can average global temperatures be used as evidence for global warming?
Global surface temperature has been measured using thermometers since 1850, the data collected since shows a general trend of steady increase in mean global temperature.
* can only show short term climate change
52
How can pollen grains preserved in peat bogs be used as evidence of climate change?
Peats cores can be taken from peat bogs and layers can be DNA analysed to asses the species of pollen grain in each layer. As different species grow under different climatic conditions the change in plant growth can be used to determine the climate at different times.
53
What is a peat bog?
A peat bog is a wetland that has very acidic conditions meaning dead plant matter cannot decompose and accumulates over time. Building up in layers.
54
How can dendrochronology be used as evidence for climate change?
Can be used to prove long term climate change. As trees grow new rings each year and the the thickness of the ring is influenced by environmental conditions the trunk core can be extracted and analysed to determine changes in environmental conditions throughout the year.
E.g. a thicker ring indicated a rise in temperature, as warmer temperatures swill increase the rate rate of growth
55
What is the meaning of anthropogenic causes?
Changes due to/originating from human activity
55
Why does scientists suggest that modern climates changes in due to anthropogenic changes?
This is because human activity have increased greenhouse gas emissions, enhancing the greenhouse effect. The greenhouse gases include water vapour, carbon dioxide, methane, nitrous oxide and sulphur hexaflouride.
55
What is the greenhouse affect and how is it caused by anthropogenic causes?
1. Human activity such as industrialisation produces water vapour, carbons dioxide and other greenhouse gases
2. These greenhouse gases build up over time in the upper atmosphere
3. The greenhouse gases absorb long wave infrared radiation, the is reflected by the earths surface
4. Preventing long wave infrared radiation escaping the atmosphere
5. Increasing global surface temperatures
55
What are the main human Causes of climate change?
- rising temperature increasing evaporation, increasing water vapour levels
- burning fossil fuels releases carbon dioxide
- deforestation released carbon dioxide and reduced photosynthesis (removing a carbon sink)
- increased agricultural practices releases methane
55
How are climate change models created?
Models can be create from existing data relating to global warming to make predictions about global temperature in the future, this is known as extrapolating from data.
55
How can global warming predictions be used?
- plan for the future (flood defences, funding climate change technology)
-encourage people to change their activity’s (education of renewables, reduced meat consumption)
56
What is the intergovernmental panel on climate change?
The IPSCC is a group of climate scientists around the world that has used existing data to extrapolate hoe global temperatures might change under different human activity scenarios.
57
What are the different scenarios predicted by the IPCC in future climate change?
- greenhouse gas concentration will peak, then reduce due to human interventions
- greenhouse gas concentration continue to increase, but level off due to human intervention
- greenhouse gas concentration continue to increase linearly
58
What are the limitations of climate change models?
- it’s unknown how greenhouse gas emissions will change in the future
- it’s unknown how much natural causes increase greenhouse gas emissions
- it’s is unknown how much greenhouse gas emissions will increase mean global surface temperature
- it’s unknown how much human intervention will occur and how successful it will be (technology)
- global climate patterns are very complex making prediction difficult
59
What are the main effects of climate change?
- warmer temperatures (impact population size, development, life cycles and distribution of species)
- greater atmospheric carbon dioxide concentration
- changing precipitation patterns (warmer air can hold more moisture)
- changing seasonality
- changing sea levels
60
How is climate change going to impact animal and plant species?
- greater growth of plants (increases photosynthetic enzymes, and greater concentrations of carbon dioxide higher rates of growth)
- greater growth and population of animals (more plants means a higher abundance of food)
- decrease growth of plants (beyond optimum temperature, enzymes will denature)
- coral bleaching (oceans absorb to much carbon dioxide making water acidic, causing Carla species to decline)
- changing development and life cycles of species (precipitation patterns and changing seasonality will impact mating and migration)
61
How is climate change impacting enzyme activity?
As temperature increases, enzymes activity will also increase up to an optimum temperature. Here enzymes will have increased kinetic energy and will form more enzyme substrate complexes. Beyond optimum temperature enzymes activity will decrease as enzymes will being denatured.
62
What is enzyme denaturing?
If temperature increases beyond optimum, enzymes become denatured. The increased kinetic energy causes statins of its hind cause the hydrogen and ionic bind to become weaker, causes the tertiary structure of the enzyme to change, changing the shape of the active site so it no longer complementary to the substrate preventing it from binding.
63
How will temperature in affect living organism?
- increase the growth of decomposes, as extracellular enzymes rate will increase speeding up the rate of decomposition
- growth in rate of photosynthesis enzymes increasing plant growth
These will both reverse if temperatures go beyond optimum temperature
- affects the sex of younge inside eggs
- species may change there distribution to changing temperatures (migrating and mating)
64
Why do some people not believe in climate change?
Some individuals do it believe the the correlation seen between humans a burning fossil fuels and global warming is a causal relationship. Claiming that the increase in temperature is causes by other factors.
65
What are the steps involved in evaluating data?
1. Hoe good it the evidence?
2. Is the data reliable?
- does it come from several independent study’s (enough evidence)
- is the source trustworthy and unbiased
66
What is the carbon cycle?
The many processes by which carbon is transferred and stored.
67
What are the steps in the carbon cycle?
1. Carbon is present in the atmosphere in the form of carbon dioxide
2. Carbon dioxide is removed form the atmosphere by producers during photosynthesis (turn into biomass)
3. Carbon is transferred to and between consumers due to feeding
4. Carbon is transferred to and between consumers as a result of feeding
5. Carbon is transferred back into the atmosphere by high pant and animals through respiration.
6. Carbon is also be removed from the atmosphere by dissolving in the oceans
7. The dissolved carbon can be taken into marine plants when they photosynthesis or by other smirks organism as they build calcium carbonate exoskeletons.
8. When living organism die their tissues are broken down by decomposers such as bacteria and fungi
9.the combustion of peat and fossil fuels release carbon dioxide back into the atmosphere.
68
How can you use knowledge of the carbon cycle to reduce carbon emissions?
At points where carbon enters the atmosphere, reducing the carbon cycle at this point will prevent further increases of carbon dioxide and increasing outputs of carbon from the atmosphere
- reducing the combustion of fossil fuels
- reducing the combustion of biomass
- reducing disturbance of carbon pools (soil and peat bogs)
- increasing rates of photosynthesis
69
What are the ways to reduce climate change?
- reducing carbon emissions (rate of fossil fuel combustion)
- biofuels (renewable, carbon neutral)
- renewable resources (wind, solar and hydroelectric energy)
- increasing carbon removal (reforestation)
70
What are biofuels?
These fuels are made form recently living plant biomass, when combusted they still release carbon dioxide.
71
What re the benefits of using biofuels?
- they are cheaper than oil
- Carbon neutral (only releasing carbon that was recently removed when plants where alive
72
What are the negatives associated with biofuels?
- still release carbon into the atmosphere
- vast amounts of land is required to grow biofuels (could have been used for food production)
- creating land for biofuel growth often involves deforestation and reduction in biodiversity
73
What is the definition of evolution?
A gene is allele frequency in a population, over a given period of time. It can happen through gene mutation and natural selection.
74
What is the process of natural selection?
1. Variation exists between individuals in a pop auction (small DNA variation and mutations)
2. Due to the variation present some individuals will have characteristics that make them better adapted for survival and reproduction
3. Individuals that don’t have advantageous allele less likely to survive and reproduce
4. Individuals with advantageous more likely to pass on the allele to offspring, and the number of individuals in a population will favourable characteristics will increase over time.
75
How does the scientific community validate evidence?
Peer review > scientist have their finding reviewed by other scientists before it published (they consider reliability and validity)
Scientific journals > finding published in scientific journals allowing other scientists to repeat the investigation
Scientific conferences > present findings to other scientists
Media reports
76
What evidence is there of evolution?
- genomics
- proteomics
77
What is genomics?
Genomic is the study in similarities whiting base sequences in different organism. Evolution suggest that all organism evolved from a common ancestor, as a result they would have similarities in DNA. The closer related two organism are the more similarities in DNA.
78
What is proteomics?
Studies similarities in the structure of proteins in different organism. Evolution suggest that all organism evolved from a common ancestor, as a result they would have similarities in DNA, and there for similarity’s in proteins.If two organisms contain similarities then they are more closely related.
79
What is sympatric speciation?
Speciation that occurs despite there being no geographical isolation.
80
Why does sympatric speciation take place?
Seasonal isolation > different breeding times
Behavioural isolation > unrecognisable breeding dances and songs
Mechanical isolation > incompatible genitals
Ecological isolation > different habitats
81
What is allopatric speciation?
Speciation that’s occurs as a result of geographical isolation.
82
What is the process of sympatric speciation?
1. Population of organisms become reproductively isolated, despite there being one geographical isolation
2. Gene flow between populations is reduced, initiating speciation
3. Random mutation causes genetic variation within a population
4. This mutation gives an organism an advantageous characteristic
5. Organism is more likely to survive and reproduce (natural selection)
6. Allele is passed on to its offspring and frequency of the allele increases in the population.
7. Populations no longer able to reproduce to make fertile offspring
83
What is the process of evolution through allopatric speciation?
1. Population of organisms become reproductively due to geographical isolation
2. Gene flow between populations is reduced, initiating speciation
3. Different population will experience different environmental conditions
4. This means the different population will experience different selectional pressures and different alleles will be more advantageous.
5. Random mutation causes genetic variation within a population
6. This mutation gives an organism an advantageous characteristic
7. Organism is more likely to survive and reproduce (natural selection)
8. Allele is passed on to its offspring and frequency of the allele increases in the population.
84
Core practical 10: how is the abundance and distribution of specie investigated practically? Random sampling
1.measure an x and y axis in a plot of land/area wanting to measure
2. Use random sampling to place quadrants randomly in the area
3. Estimate the percentage cover of the species within the quadrat.
4. Measure relevant abiotic factors (temperature, soil pH)
5. Record data in a table
6. Repeats in different locations and compare results, calculate a mean and identify anomalies.
85
Core practical 10: how is the abundance and distribution of specie investigated practically? Transect sampling
1. Measure a 30 metre transect line using a tape measure
2. Use of systematic sampling
3. Place a quadrat at 3 m intervals along the transect line
4. Estimate percentage cover of a species within the quadrat.
5. Measure relevant abiotic factors (temperature, soil pH)
6. Record data in a table
7. Repeats in different locations and compare results, calculate a mean and identify anomalies.
86
Core practical 11: investigating photosynthesis using isolated chloroplast (Hills reaction) - variables
Control variable > species of a plant, age of plant, light intensity, temperature, pH, volume of isolation solution ect
Independent variables > light intensity, temperature, CO2 concentration or pH
Dependent > absorbance of reaction mixture
87
Core practical 11: investigating photosynthesis using isolated chloroplast (Hills reaction) - methods
1. Grind up a plant sample making sure photosynthetic enzymes aren’t denatured
2. Add isolation solution (sucrose, potassium chloride and pH buffer)
3. Filter solution using a funnel lined with muslin cloth
4. Transfer solution into a centrifuge for 10 minutes causing the chloroplast to gather at the bottom of the solution in pellets.
5. Place pellets in anew isolation solution
6. Set colorimeter to ref filter and calibrate colorimeter so it measures 0 abs for a curettes coat isn’t pellets and new isolation solution
7. Add 5cm3 log pellets, new isolation solution and 2cm3 of DCPIP
8. Decant staple of reaction moisture into a corvette and place cuvette into colorimeter and measure absorbance
10. Repeat every 10 minutes and put a graph and calculate initial rates of reaction.
88
What is the hills reaction?
The process by which NADP is reduced to form NADH is PSI when electrons and a hydrogen ion are transferred to NADP (electron acceptor). DCPIP will turn from blue to colourless when reduced (accepts an electron)
89
Core practical 12: investigate the effect of temperature on the Italian rate of an enzyme catalyses reaction (Q10) - variables
Control > type, volume and concentration of enzyme, type, volume and concentration of substrate, time for reaction to occur and pJ (use buffer)
Independent > enzyme concentration, substrate concentration or temperature
Dependent > volume of oxygen gas every 10 seconds (initial rate)
90
Core practical 12: investigate the effect of temperature on the Italian rate of an enzyme catalyses reaction (Q10) - method
1. Place solutions in water baths at five different temperatures
2. Add 1 cm3 catalase, 5 cm3 of hydrogen peroxide and 1cm3 kd buffer to conceal flask
3. Apply bing and collect oxygen gas in a burette submerged in water baths
4. Measure amount of gas produced every 10 seconds for 1 minute
5. Plot graph and calculate initial rate of reaction
6. Calculate temperature coefficient (Q10)
7. Repeat with other temperatures
91
What is the temperature coefficient?
The temperature coefficient (Q10) calculates the ratio of the rate of an enzyme reaction taking place when the temperature is increased by 10 degrees.
Q10 = rate at higher temperature / rate at lower temperature
92
Core practical 13: investigate the effect of temperature of the development of organisms - seedling growth rate
1. Plant seeds in soil (control species, age and soil nutrients)
2. Place seeds in incubator at 5 different temperatures
3. Control abiotic factors humidity, light intensity, wind ect
4. Grow for 9 days
5. Measure growth everyday (mass, shoot, length)
6. Calculate average growth rate
7. Repeats with other temperatures and calculate the mean
93
Core practical 13: investigate the effect of temperature of the development of organisms - shrimp hatch rate
1. Place shrimp eggs in test tube (control species, age and number of eggs)
2. Place test tubes in water baths at 5 different temperatures (control oxygen conc, volume of water and salinity)
3. Measure the number of hatched shrimp eggs every other day
4. Calculate average hatch rate (average number of hatched shrimp / time)
5. Repeat with other temperatures
