Topic 5 Photsynthesis evolution Climate Flashcards
1
Q
What is an ecosystem?
A
All the organisms living in a particular area and all the non-living (abiotic) factors
Ecosystems include both living (biotic) and non-living components interacting together.
2
Q
Define habitat.
A
The place where an organism lives, e.g. a rocky shore or a field
Habitats provide the necessary resources for organisms to thrive.
3
Q
What is a population in ecological terms?
A
All the organisms of one species in a habitat
Population refers specifically to individuals of a single species.
4
Q
What does community refer to in ecology?
A
All of the organisms of different species that live in the same habitat and interact with each other
Communities are made up of multiple populations.
5
Q
Define abiotic factors.
A
The non-living features of the ecosystem, e.g. temperature and availability of water
Abiotic factors are crucial for the survival of organisms.
6
Q
What are biotic factors?
A
The living features of the ecosystem, e.g. the presence of predators or food
Biotic factors influence population dynamics and community structure.
7
Q
What is abundance in ecological terms?
A
The number of individuals of one species in a particular area
Abundance is synonymous with population size.
8
Q
How does population size vary with abiotic factors?
A
Population size varies due to factors like light, water, space, temperature, and chemical composition
Ideal abiotic conditions support faster growth and reproduction.
9
Q
What happens to population size when abiotic conditions are not ideal?
A
Organisms cannot grow as fast or reproduce successfully
This often leads to decreased population sizes due to increased energy expenditure.
10
Q
What is interspecific competition?
A
Competition between different species for the same resources
Example: Red and grey squirrels competing for food sources.
11
Q
What is intraspecific competition?
A
Competition within a species for the same resources
Intraspecific competition can lead to population fluctuations.
12
Q
Define carrying capacity.
A
The maximum stable population size of a species that an ecosystem can support
Carrying capacity is influenced by resource availability.
13
Q
What is predation?
A
Where an organism (the predator) kills and eats another organism (the prey)
Predation is a key factor in regulating population sizes.
14
Q
How are predator and prey populations linked?
A
As prey population increases, predator population grows; as predator population increases, prey population decreases
This dynamic relationship is crucial for ecosystem balance.
15
Q
Fill in the blank: Organisms can only exist where the abiotic factors they can survive in _______.
A
exist
This highlights the importance of abiotic conditions in habitat suitability.
16
Q
Give an example of how abiotic factors affect distribution.
A
Some plants only grow on south-facing slopes in the northern hemisphere due to light intensity
This demonstrates the relationship between abiotic factors and organism distribution.
17
Q
True or False: Large trees can grow in polar regions.
A
False
Large trees cannot grow in polar regions due to extremely low temperatures.
18
Q
What is interspecific competition?
A
Competition between different species for resources.
19
Q
Give one example of interspecific competition.
A
The grey squirrel outcompeting the native red squirrel in the UK.
20
Q
Define the term niche.
A
The role of a species within its habitat.
21
Q
What are the two types of interactions included in a niche?
A
- Biotic interactions
- Abiotic interactions
22
Q
True or False: A niche can be occupied by more than one species.
A
False.
23
Q
What does abundance refer to in ecology?
A
The number of individuals of one species in a particular area.
24
Q
What is the difference between habitat and niche?
A
Habitat is where a species lives; niche is what it does in that habitat.
25
How can abiotic factors affect the abundance of organisms? Give one example.
Factors like temperature or moisture level can impact survival and reproduction.
26
Give two examples of abiotic factors that can affect the distribution of organisms.
* Temperature
* Soil salinity
27
What is the purpose of sampling in ecological studies?
To investigate the abundance and distribution of species.
28
What is random sampling?
Choosing sample sites without bias to accurately represent the habitat.
29
What is systematic sampling?
Sampling at fixed intervals, often along a line.
30
Define intraspecific competition.
Competition between individuals of the same species.
31
What is a frame quadrat used for?
To investigate immobile populations by recording species within a defined area.
32
How is percentage cover measured in a frame quadrat?
By counting how much of the quadrat is covered by the plant species.
33
Fill in the blank: The _______ concept explains how different species can coexist by occupying different niches.
[niche]
34
What is an environmental gradient?
A habitat that changes gradually in abiotic factors.
35
True or False: The abundance of species can be simply counted by sampling.
True.
36
What is the role of abiotic factors in the distribution of organisms?
They determine the conditions necessary for species survival.
37
What should be done when comparing different habitats during sampling?
Always use the same sampling technique.
38
Explain the term 'predator-prey relationships'.
Interactions where predators hunt and feed on prey species.
39
What can affect the chance of survival for species in a habitat?
The presence of better-adapted species.
40
In terms of ecological research, what is the significance of taking multiple samples?
It provides a better indication of the whole habitat.
41
What is a point quadrat?
A horizontal bar on two legs with a series of holes at set intervals along its length.
42
How is a point quadrat used in investigating plant populations?
It is placed on the ground at random points, and pins are dropped through the holes to record every plant touched.
43
What should be recorded if a pin touches several overlapping plants?
All of them are recorded.
44
How is the percentage cover of a species calculated using point quadrats?
By calculating the number of pins that touch a given species as a percentage of the total number of pins dropped.
45
In what type of areas are point quadrats especially useful?
In areas with dense vegetation close to the ground.
46
What is the purpose of using transects in ecological studies?
To investigate the distribution of plant populations across an area.
47
What is a line transect?
A tape measure is placed along the transect, and species that touch the tape measure are recorded.
48
Describe a belt transect.
Data is collected along the transect line using frame quadrats placed next to each other.
49
What are interrupted transects?
Measurements are taken at intervals along the transect instead of investigating the whole transect.
50
What is a kite diagram used for?
To plot the abundance and distribution of organisms in an area.
51
How does the thickness of the kite shape in a kite diagram represent abundance?
The thickness shows the abundance of each organism.
52
What does the x-axis in a kite diagram represent?
The distance along the transect line.
53
What is climate in the context of abiotic factors?
The weather conditions of a region over a long period of time.
54
How is temperature measured in ecological studies?
Using a thermometer.
55
What device is used to measure rainfall?
A rain gauge with a funnel attached to a measuring cylinder.
56
How is humidity measured?
Using an electronic hygrometer.
57
What is the purpose of measuring oxygen availability?
To assess the amount of oxygen dissolved in aquatic habitats.
58
What tool measures solar input (light intensity)?
An electronic light sensor.
59
How is soil pH measured?
Using indicator liquid or electronic pH monitors.
60
Describe how moisture content of soil is measured.
By measuring the mass of soil before and after drying it in an oven.
61
What is relief in terms of topography?
How the height of the land changes across a surface.
62
How can slope angle be measured?
Using a clinometer.
63
What does aspect refer to in topography?
The direction a slope is facing.
64
Fill in the blank: The results of investigations into the abundance and distribution of organisms can be plotted on a _______.
kite diagram.
65
True or False: Point quadrats can only be used in fields.
False.
66
What is the purpose of using frame quadrats in estimating percentage cover?
To sample a population of plants in a specific area.
67
State two ways climatic conditions could be measured.
* Temperature
* Rainfall
68
What is succession in ecology?
The process of ecosystem change over time.
69
What are the two types of succession?
* Primary succession
* Secondary succession
70
What is primary succession?
Succession that occurs on land that has never been formed or exposed, starting with bare rock.
71
What is secondary succession?
Succession that occurs on land that has been disturbed but where soil remains, such as after a forest fire.
72
What are pioneer species?
The first species to colonize an area during succession.
73
How do pioneer species affect abiotic conditions?
They change abiotic conditions by dying and decomposing, which helps form soil.
74
Fill in the blank: The final stage of succession is called the _______.
climax community.
75
What happens to biodiversity as succession progresses?
Biodiversity increases.
76
What is a climax community?
The ecosystem that supports the largest and most complex community of plants and animals.
77
Explain the role of lichens in primary succession.
Lichens grow on bare rock, break it down, and release minerals, contributing to soil formation.
78
What is a plagioclimax?
A climax community that is artificially prevented from developing.
79
How can human activities prevent succession?
By regularly mowing or disturbing the land, preventing larger plants from establishing.
80
True or False: Secondary succession starts with bare rock.
False.
81
What changes occur in the soil during primary succession?
The soil deepens and becomes richer in minerals as organic material accumulates.
82
What type of succession occurs after a forest fire?
Secondary succession.
83
Fill in the blank: The process of succession leads to an increase in _______.
ecosystem complexity.
84
What is the relationship between succession and competition among species?
Different plants and animals out-compete others for dominance as conditions improve.
85
What climatic factors influence the types of climax communities?
* Temperature
* Precipitation
86
Describe the role of grasses in dune succession.
Grasses can stabilize sand and improve conditions for larger plants like shrubs.
87
What happens to species composition during succession?
Species composition changes as new species move in and out-compete existing ones.
88
What is photophosphorylation?
Adding phosphate to a molecule using light.
89
Define photolysis.
The splitting of a molecule using light energy.
90
What are redox reactions?
Reactions that involve oxidation and reduction.
91
What happens during oxidation?
A molecule loses electrons and may lose hydrogen or gain oxygen.
92
True or False: Oxidation of one molecule always involves reduction of another molecule.
True.
93
List some biological processes that require energy in plant cells.
* Photosynthesis
* Active transport
* DNA replication
* Cell division
* Protein synthesis
94
List some biological processes that require energy in animal cells.
* Muscle contraction
* Maintenance of body temperature
* Active transport
* DNA replication
* Cell division
* Protein synthesis
95
What is the overall equation for photosynthesis?
6CO₂ + 6H₂O + Energy → C₆H₁₂O₆ (glucose) + 6O₂
96
How do plants store energy from photosynthesis?
In glucose, which is released by respiration.
97
How do animals obtain glucose?
By eating plants or other animals.
98
What is ATP?
Adenosine triphosphate, the immediate source of energy in a cell.
99
How is ATP synthesized?
By the phosphorylation of ADP using energy from an energy-releasing reaction.
100
What enzyme catalyzes the synthesis of ATP?
ATP synthase.
101
What happens to ATP when it diffuses to the part of the cell that needs energy?
It is broken down via hydrolysis back into ADP and inorganic phosphate.
102
What is the role of ATPase?
Catalyzes the reaction that breaks down ATP into ADP and inorganic phosphate.
103
What are chloroplasts?
Flattened organelles found in plant cells that are the site of photosynthesis.
104
What is the structure that keeps the reactants for photosynthesis close to their reaction sites?
Chloroplast envelope.
105
What are thylakoids?
Fluid-filled sacs in chloroplasts that have a large surface area for light absorption.
106
What are grana?
Stacks of thylakoids in the chloroplast.
107
What are the two types of photosystems used by plants?
* Photosystem I (PSI)
* Photosystem II (PSII)
108
At what wavelength does Photosystem I absorb light best?
700 nm.
109
At what wavelength does Photosystem II absorb light best?
680 nm.
110
What is the stroma?
The gel-like substance surrounding the thylakoids in chloroplasts.
111
Fill in the blank: The process used to synthesize ATP from ADP is called ______.
phosphorylation.
112
What are the two stages of photosynthesis?
1) Light-Dependent Reaction 2) Light-Independent Reaction (Calvin Cycle)
## Footnote
The Light-Dependent Reaction requires light energy, while the Light-Independent Reaction does not.
113
Where does the Light-Dependent Reaction take place?
In the thylakoid membranes of the chloroplasts
## Footnote
This stage involves the absorption of light energy by photosynthetic pigments.
114
What are the products of the Light-Dependent Reaction?
* ATP * Reduced NADP * Oxygen
## Footnote
These products are used in the Light-Independent Reaction.
115
What is photophosphorylation?
The process of making ATP from ADP and inorganic phosphate using light energy
## Footnote
This occurs during the Light-Dependent Reaction.
116
What does the term 'photolysis' refer to?
The splitting of water into protons, electrons, and oxygen
## Footnote
This process occurs during the Light-Dependent Reaction.
117
What is the primary role of the electron transport chain in photosynthesis?
To transfer excited electrons and create a proton gradient
## Footnote
This gradient is essential for ATP synthesis.
118
What is chemiosmosis?
The process where the movement of H+ ions across a membrane generates ATP
## Footnote
This process also occurs in respiration.
119
What is cyclic photophosphorylation?
A process that only uses PSI, where electrons are recycled back to PSI
## Footnote
This process produces only ATP and no reduced NADP or oxygen.
120
Where does the Light-Independent Reaction (Calvin Cycle) take place?
In the stroma of the chloroplasts
## Footnote
This stage does not directly use light energy.
121
What is glyceraldehyde 3-phosphate (GALP)?
A molecule made from CO2 and ribulose bisphosphate in the Calvin Cycle
## Footnote
GALP can be used to synthesize glucose and other organic substances.
122
What is the role of ATP and reduced NADP in the Calvin Cycle?
They provide energy and hydrogen ions necessary for the cycle
## Footnote
These are supplied by the Light-Dependent Reaction.
123
What is carbon dioxide fixation?
The process of incorporating carbon from CO2 into an organic molecule
## Footnote
This occurs during the Calvin Cycle.
124
Fill in the blank: The light energy is used to add a phosphate group to ADP to form _______.
ATP
125
True or False: Light-Dependent Reactions produce glucose directly.
False
## Footnote
Glucose is produced in the Light-Independent Reaction (Calvin Cycle).
126
What is the role of RUBISCO in the Calvin cycle?
RUBISCO catalyses the reaction between CO2 and ribulose bisphosphate (RuBP) to form a 6-carbon compound
127
What does the unstable 6-carbon compound break down into during the Calvin cycle?
Two molecules of a 3-carbon compound called glycerate 3-phosphate (GP)
128
How many ATP molecules are required for the reduction of GP to glyceraldehyde 3-phosphate (GALP)?
2 x ATP
129
What are the products of the Calvin cycle?
Glyceraldehyde 3-phosphate (GALP) and ribulose bisphosphate (RuBP)
130
Which organic substances can be produced from GALP and GP?
* Carbohydrates
* Lipids
* Amino acids
* Nucleic acids
131
Fill in the blank: The sugar in RNA (ribose) is made using _______.
GALP
132
True or False: Five out of every six molecules of GALP produced in the Calvin cycle are used to make hexose sugars.
False
133
What is the purpose of the DCPIP dye in the investigation of the Hill reaction?
DCPIP acts as an electron acceptor and gets reduced during the light-dependent reactions
134
What happens to the color of DCPIP as the Hill reaction occurs?
DCPIP changes from blue to colorless
135
How is ribulose bisphosphate (RuBP) regenerated in the Calvin cycle?
By using the remaining ATP produced in the light-dependent reactions
136
What is the effect of CAIP on glucose production?
CAIP inhibits RUBISCO, which would decrease glucose production
137
Where in the chloroplasts does the light-independent reaction occur?
In the stroma
138
Describe the experimental setup for measuring the rate of the Hill reaction.
Use a colorimeter to measure absorbance of DCPIP in chloroplast extract exposed to light
139
What is the significance of preparing negative control tubes in the Hill reaction experiment?
To show that the DCPIP color change occurs only due to chloroplast activity and not naturally over time
140
What is the initial reactant combined with ribulose bisphosphate in the Calvin cycle?
CO2
141
What is the outcome of the hydrolysis of ATP in the Calvin cycle?
It provides energy to convert GP into glyceraldehyde 3-phosphate (GALP)
142
Fill in the blank: The Calvin cycle is the starting point for making all the _______ substances a plant needs.
organic
143
What is the role of producers in an ecosystem?
Producers produce organic molecules using sunlight energy.
144
What is biomass in the context of energy transfer?
Biomass is the mass of living material, representing stored energy.
145
Who are primary consumers?
Organisms that eat producers.
146
What happens to energy when organisms eat other organisms?
Energy is transferred through the living organisms of an ecosystem.
147
What percentage of energy is typically lost at each trophic level?
Around 90% of the total available energy is lost.
148
List some reasons why energy is lost in ecosystems.
* Plants can't use all light energy reaching their leaves
* Some light hits non-photosynthesizing parts of plants
* Parts of food are not eaten
* Indigestible parts of food pass as waste.
149
What is gross productivity?
The total energy absorbed by organisms.
150
What is respiratory loss?
Energy lost to the environment during respiration for movement or body heat.
151
Define net productivity.
The amount of energy available to the next trophic level.
152
How is net productivity calculated?
Net productivity = gross productivity - respiratory loss.
153
What is the formula for calculating the efficiency of energy transfer?
(net productivity ÷ energy received) * 100.
154
Fill in the blank: Net primary productivity (NPP) is calculated using the formula NPP = _______.
GPP - plant respiration.
155
What factors can lower net primary productivity?
Cold temperatures and low light availability.
156
How is energy transfer between trophic levels measured?
By calculating the difference in net productivity between levels.
157
What is dry mass and why is it used in measuring energy transfer?
Dry mass is the mass of organisms after removing water; it indicates stored energy.
158
What ethical considerations are there when measuring the dry mass of animals?
Killing animals for measurement may not be ethical.
159
What is a potential issue when estimating energy transfer between trophic levels?
Consumers may have taken in energy from other sources, complicating calculations.
160
True or False: All energy in an ecosystem is efficiently transferred from one trophic level to another.
False.
161
What is meant by 'gross primary productivity'?
The total amount of energy produced by photosynthesis in plants.
162
Calculate the net productivity if gross productivity is 8000 kJ/m²/yr and respiratory loss is 6000 kJ/m²/yr.
2000 kJ/m²/yr.
163
How can one calculate the percentage efficiency of energy transfer from one trophic level to another?
By using the formula: (net productivity ÷ energy received) * 100.
164
What is the role of producers in an ecosystem?
Producers produce organic molecules using sunlight energy.
165
What is biomass in the context of energy transfer?
Biomass is the mass of living material, representing stored energy.
166
Who are primary consumers?
Organisms that eat producers.
167
What happens to energy when organisms eat other organisms?
Energy is transferred through the living organisms of an ecosystem.
168
What percentage of energy is typically lost at each trophic level?
Around 90% of the total available energy is lost.
169
List some reasons why energy is lost in ecosystems.
* Plants can't use all light energy reaching their leaves
* Some light hits non-photosynthesizing parts of plants
* Parts of food are not eaten
* Indigestible parts of food pass as waste.
170
What is gross productivity?
The total energy absorbed by organisms.
171
What is respiratory loss?
Energy lost to the environment during respiration for movement or body heat.
172
Define net productivity.
The amount of energy available to the next trophic level.
173
How is net productivity calculated?
Net productivity = gross productivity - respiratory loss.
174
What is the formula for calculating the efficiency of energy transfer?
(net productivity ÷ energy received) * 100.
175
Fill in the blank: Net primary productivity (NPP) is calculated using the formula NPP = _______.
GPP - plant respiration.
176
What factors can lower net primary productivity?
Cold temperatures and low light availability.
177
How is energy transfer between trophic levels measured?
By calculating the difference in net productivity between levels.
178
What is dry mass and why is it used in measuring energy transfer?
Dry mass is the mass of organisms after removing water; it indicates stored energy.
179
What ethical considerations are there when measuring the dry mass of animals?
Killing animals for measurement may not be ethical.
180
What is a potential issue when estimating energy transfer between trophic levels?
Consumers may have taken in energy from other sources, complicating calculations.
181
True or False: All energy in an ecosystem is efficiently transferred from one trophic level to another.
False.
182
What is meant by 'gross primary productivity'?
The total amount of energy produced by photosynthesis in plants.
183
Calculate the net productivity if gross productivity is 8000 kJ/m²/yr and respiratory loss is 6000 kJ/m²/yr.
2000 kJ/m²/yr.
184
How can one calculate the percentage efficiency of energy transfer from one trophic level to another?
By using the formula: (net productivity ÷ energy received) * 100.
