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136 Cards in this Set
- Front
- Back
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What is the biosphere? |
The part of earth inhabited by living organisms |
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What are abiotic factors? |
Physical and chemical factors like the climate and soil type (Non living) |
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What are biotic factors? |
Factors determined by organisms, such as predation and competition. |
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What is an ecosystem? |
Hard to define, in principle an area that tends to be fairly self sustaining. Such as a lake or some woods |
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What is a habitat? |
A place with a distinct set of conditions where an organism lives? |
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What is a population? |
A group of individuals of the same species found in an area |
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What makes up a community (in a ecosystem or habitat) ? |
The various populations sharing the habitat or ecosystem. population- group of the SAME species so community is all the species in the area |
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What is a niche? |
The way an organism fits into an ecological community (Food source, time of feeding, shelter site) |
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What will happen if two species occupy the same niche within a habitat? |
They will compete with each other. The better adapted of the two will eventually out compete the other and exclude it from the habitat. |
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Two species are able to occupy the same habitat only if.... |
they occupy different niches. |
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What determines the particular habitat that a species inhabits? |
It`s adaptions It is able to survive and reproduce in this habitat. |
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Is Solar Energy input an abiotic or biotic factor? |
Abiotic The amount of light (affected by lattitude, season, cloud cover and changes in the earths orbit) Light is vital to plants for photosynthesis and can initiate flowering (phytochrome R to FR) |
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Is Competition a biotic or abiotic factor? |
Biotic |
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What is intraspecific competition? |
Competition within species |
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What is interspecific competition? |
Competition between species |
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Is climate an abitotic or biotic factor? |
Abiotic Rainfall, wind exposure and temperature |
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Is Topography a abiotic or biotic factor? |
Abiotic Includes altitude, slope, aspect (which direction the land faces) and drainage. |
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What Biotic factors are there? |
Grazing Predation Parasitism Competition (inter and intraspecific) |
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What is mutalism? |
A relationship where both partner benefit? |
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What is an edaphic factor? |
Factors connected with the soil (abiotic) includes soil pH and mineral salt availability |
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As conditions become more stable and more nutrients are available what happens to the diversity of organisms? |
Greater diversity of organisms as conditions become more stable and nutrients are available |
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What are anthropogenic factors? |
Those arising from human activity. |
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What is our (humans) ecological footprint? |
The impact of humans on the world enviroment. |
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What adaptions make a polar bear suitable for it`s habitat? |
Thick fur - reduce heat loss Small ears - reduce heat loss Thick layer of fat under fur - reduce heat loss Remain in den in winter, cubs emerge in spring - helps bear survive harsh winter conditions Long nose with several passages - warms air before it enters lungs |
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What is a herbivore? |
An animal that feeds on plants. |
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What adaptions do plants have to withstand grazing? |
Being prickly Stinging Mimicking appearance of stinging plants Being unpalatable (unpleasant taste) |
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What features of a wild rabbit help it avoid predators? |
Large ears White tail - distracts and confuses predator |
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What is succession? |
The process by which the structure of a biological community evolves over time. |
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When does primary succession occur? |
On a newly formed habitat where there has never been a community before. |
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Where does secondary succession occur? |
On bare soil where an existing community has been cleared. |
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What is the first stage of succession? |
The pioneer phase; the pioneer species can cope with the extremes of the temperature and lack of soil water and nutrients. |
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what do the pioneer do that helps shallow rooted plants to develop? |
They start to break up the rock surface, allowing some organic material to accumulate with this broken rock as the beginnings of soil. |
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What builds up more organic matter in the soil? |
Wind blown moss spores start growing, these can hold water and build up the organic matter in the soil. |
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What happens once the development of soil occurs? |
Small, shallow-rooted plants can establish. |
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What happens as conditions in the habitat start to improve? |
Seeds from larger, taller plants appear. |
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What is eventually reached? |
A climax community. |
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What is a climax community? |
a biological community of plants, animals, and fungi which, through succession, has reached a steady state. |
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What is a dominant species in a community? |
One that exerts an overriding influence over the rest of the species (plant, microbe and animal) usually the largest or most abundant plant species in the community. |
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What happens to the number of niches as succession progresses? |
The number of niches increases |
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Does the climax community ALWAYS have higher biodiversity than the preceding stages of succession? |
No |
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What controls the numbers and distribution of organisms in a habitat? |
Abiotic and biotic factors |
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Does the climax community always end up as forest or woodland? Why might this not happen |
No |
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What might lead to secondary succession? |
If a field has been ploughed or after a forest fire. |
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What are characteristics of a pioneer species? |
Abundant seed production Rapid growth Seeds widely dispersed by the wind Short life cycle |
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What is deflected succession? |
A community that remains stable only because human activity prevents succession from running it`s course. |
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Examples of deflected succession |
Sheep grazing in Britain prevents many grasslands developing into woodland. Grazing, mowing or burning can be used to deflect succession. |
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What is the primary productivity of an ecosystem? |
The rate at which energy is incorporated into organic molecules in an ecosystem. |
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What is an autotroph? |
Also known as a producer An organism that can make it`s own organic compounds from inorganic compounds. |
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Not all producers are photosynthetic, they can also be... |
Chemo-synthetic |
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How is primary productivity linked to Biodiversity? |
Productive ecosystems have a greater diversity of plants than ecosystems with low primary productivity. |
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What is photosynthesis? |
The process by which green plants and some other organisms use sunlight to synthesize nutrients from carbon dioxide and water. |
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What is the simple overall equation for photosynthesis? |
6C02 + 6H2O -----------> C6H1202 + 6O2 In the presence of chlorophyll and using energy from light. |
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Carbon Dioxide is _______________ as hydrogen and electrons from water are added to it, creating a ____________________. |
Reduced (OIL RIG) Carbohydrate |
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Is energy released when bonds are made or broken? |
Bond-making is an exothermic process. |
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Therefore a reaction is endothermic if... So photosynthesis is ... |
energy absorbed is more than the energy released Energy absorbed breaking bonds in carbon dioxide and water is greater than the energy released when bonds are formed in glucose and oxygen. |
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What happens with the products of photosynthesis? |
Glucose is a fuel, which can later be oxidised during respiration to release energy. Oxygen is a waste product and released into atmosphere. |
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When hydrogen reacts with oxygen... |
Lots of energy released. and water produced |
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In photosynthesis the hydrogen is separated from _____________ and stored within a ________ |
Water
Carbohydrate |
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When energy is required in a cell what happens? |
The hydrogen stored in the carbohydrate reacts with oxygen during respiration, releasing a large amount of energy. |
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What is photolysis? |
The splitting of water into hydrogen and oxygen. |
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What happens to the carbon dioxide to form the carbohydrate glucose? |
It is reduced. |
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How can this glucose be used? |
In aerobic respiration to release energy |
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What can glucose be converted into using enzymes? |
Starch, cellulose, Fats, Amino Acids/Proteins and nucleic acids. |
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Where do the extra elements needed to make some of these compounds come from? |
Nitrogen and Phosphorus are taken up by the root of the plant from the soil. |
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Why are animals totally dependent on plants for their existence? |
Animals cannot make all the organic compounds they need for themselves. These can be passed to animals when they eat plants. |
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What are the two stages of photosynthesis? |
Light dependent reactions Light independent reactions |
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What happens in the light dependent reactions? |
Energy from light and hydrogen from photolysis of water to produce reduce NADP, ATP and the waste product oxygen. |
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What happens to this oxygen |
Either used directly in respiration or released into atmosphere |
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What happens in the light independent reactions? (Summary) |
The reduced NADP and ATP from the light dependent reactions are used to reduce carbon dioxide to carbohydrates. |
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What is meant by reduction? |
The addition of electrons (OIL RIG) |
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Can hydrogen ions carry out reduction? |
No, since they do not carry an electron. A hydrogen ion is just a proton. |
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What can hydrogen ions control? |
pH |
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Do CO2 and H2O have direct contact in photosynthesis? |
No the carbon dioxide and water never have direct contact. |
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What is ATP? |
An energy transfer molecule |
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Where does photosynthesis take place? |
In the cholorplast |
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Which type of cell contains chloroplasts? |
Palisade mesophyll cell |
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What happens (step by step) in light dependent reactions? First... |
Energy from light raises two electrons in each chlorophyll molecule to a higher energy. The chlorophyll molecules are now in an excited state. |
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What happens next? |
The electrons leave the excited chlorophyll molecules and pass along a series of electron carrier molecules, all of which are embedded in the thylakoid membranes. |
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What happens to the electrons as they travel down the electron transport chain? |
The electrons pass from one carrier to the next in a series of oxidation and reduction reactions, losing energy in the process. |
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What happens to this lost energy? |
It is used in the synthesis of ATP ATP used in light independent reactions |
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What is photo-phosphorylation? |
Phosphorylation of ADP to form ATP using the energy of sunlight. |
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What must occur if the flow of electrons along the electron transport chain is to continue? |
The electrons lost from the chlorophyll must be replaced. |
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How are these electrons replaced? |
Photolysis splits water to give oxygen gas, hydrogen ions and electrons. These electrons replace those that were emitted from the chlorophyll molecule, so it is no longer positively charged. |
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What happens to the hydrogen ion concentration within the thylakoid membranes due to photolysis? |
It is raised |
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What happens to the electrons as they reach the end of the electron transport chain? |
They combine with the co enzyme NADP |
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Where do they light independent reactions occur? |
In the stroma |
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What is the stroma? |
The fluid surrounding the thylakoid membranes. It contains all the enzymes needed to carry out the light-independent reactions of photolysis. |
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What is the thylakoid space? |
The fluid within the thylakoid membranes contains enzymes for photolysis |
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What is the granum? |
The stack of thylakoids joined to one another. Grana (pl) resemble stacks of coins. |
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What is the role of ATP? |
It moves energy around the cell from energy-yielding reactions to energy-requiring reactions. |
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What is a metabolic pathway? |
A series of steps found in biochemical reactions that help convert molecules or substrates, such as sugar, into different, more readily usable materials. A set of smaller reactions, each controlled by a specific name, to help control an overall reaction. |
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What goes INTO the light independent reaction? |
Reduced NADP and ATP from light dependent reactions Carbon Dioxide |
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What is the role of NADP in photosynthesis? |
Acts as a hydrogen carrier So it can`t react with oxygen as it is transferred from water to carbon dioxide. |
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What is the cyclical pathway in photosynthesis? |
The calvin cycle. |
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What are the products of the Calvin cycle? |
Carbohydrate - combining the carbon dioxide with the hydrogen from water. ADP and inorganic phosphate (when ATP used) |
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What is added to the 5 carbon compound (RuBP) to form the 6 carbon compound (GP) in the Calvin cycle? |
Carbon Dioxide |
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What enzyme catalyses the combination of carbon dioxide with RuBP? |
RuBISCO |
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How is GP converted to GALP? |
It is reduced. The hydrogen for the reduction comes from the reduced NADP ATP from the light-dependent reaction provides the energy required for the reaction. |
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What happens to two of every 12 GALPs formed? |
They are involved in the creation of a 6-Carbon sugar which can be converted to other organic compounds, for example amino acids or lipids. |
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What happens to the other 10 GALP molecules? |
Involved in the recreation of RuBP. (GALP molecules are phosphorylated using ATP) |
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How are the thylakoids specialized for the light dependent reactions? |
Electron carriers are located within thylakoid membrane in chloroplast. Creating an electron transport chain. |
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How is the stroma suitable for light - independent reactions? |
Making a high concentration of RuBISCO and other enzymes throughout the cell would be very costly in terms of synthesis of enzyme. whereas a low concentration would reduce the rate of reaction and efficiency of photosynthesis Compartmentalization of reactions within chloroplast stroma allows enzymes and substrates to be at concentrations that allow the reactions to be catalyzed quickly. |
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What is a heterotroph? |
Organisms that obtain energy as ready made organic matter by ingesting material from other organisms. |
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All heterotrophs are... |
Consumers |
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Primary consumers/herbivores are |
heterotrophs that eat plant material |
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secondary consumers/carnivores feed on |
Primary consumers |
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Tertiary consumers (also carnivores) feed on |
other consumers, the carnivores at the top of the food chain are sometimes called top carnivores. |
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What are animals that kill and eat other animals known as |
predators and carnivores (flesh eaters) |
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What are animals that eat plants and other animals known as? |
omnivores |
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What is a food chain? |
The feeding relationship between primary consumers, secondary consumers and then sometimes tertiary consumers. |
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The position a species occupies in a food chain is called a... |
trophic level |
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how is energy transferred from one trophic level to the next |
by consumers (eating) |
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what is a food web? |
a system of interlocking and interdependent food chains |
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what is a dertivore? |
a primary consumer that feeds on dead organic material called detritus |
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What are examples of detrivores? |
Woodlice, earthworms and freshwater shrimps are examples of detrivores. |
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What are decomposers? |
Species of bacteria and fungi that feed on the dead remains of organisms and animal faeces. |
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What do decomposers and detrivores play an important role in recycling? |
Organic matter from dead remains and waste |
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How do decomposers digest their food? |
They secrete enzymes and digest their food externally. Then they absorb it. |
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What does the productivity of an ecosystem depend on? |
How much energy is captured by the producers, and how much is transferred to the higher trophic levels. |
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What happens to the light reaching the plant leaf that is not absorbed by chlorophyll? (40% is absorbed by chlorophyll) |
5% reflected 50% used in evaporating water from leaves 5% transmitted straight through leaf |
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What is the law of limiting factors? |
The law of limiting factors states that when a process if affected by more than one factor, it`s rate is limited by the factor furthest from its optimum value. |
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What are the main limiting factors for photosynthesis/ |
Carbon dioxide Concentration Temperature Light intensity |
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What is Gross Primary Productivity? (GPP) |
GPP is the rate at which energy is incorporated into organic molecules by an ecosystem? |
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What is GPP measured in? |
Units of energy per unit area per year (kJ m-2 y-1) |
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What provides the energy for the plants life processes? |
Respiration |
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What happens to carbohydrates made in photosynthesis not used in respiration? |
They are incorporated into new proteins, chromosomes, membranes and other components of new cell. Made into new plant biomass |
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What is Net Primary Productivity? (NPP) |
The rate at which energy is transferred into the organic molecules that make up new biomass. |
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How are NPP, GPP and R (respiration) related to each other? |
NPP = GPP - R ( NPP + R = GPP ) |
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Transfer of energy from producers to primary consumers is not very efficient? What happens to the rest of the energy in producers that does not end up as herbivore biomass? (3) |
Not all the available food is eaten some parts of plants such as roots, twigs and parts protected by spines will not be eaten. Some energy is lost in faeces and urine some parts of plant such as cellulose in cell wall cannot be broken down by mammals. Lots of energy absorbed by consumers goes into respiration not new biomass respiration provides energy for movement and chemical reactions in body. |
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Why is transfer of energy from primary consumers to secondary consumers more efficient than between producers and primary consumers? |
Most of a herbivore may be eaten by a carnivore Protein rich diet easier to digest so less lost in faeces. |
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The energy entering a trophic level must equal... |
the amount of energy used or lost by that trophic level. |
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what is the equation for energy entering a trophic level (energy consumed by a trophic level)? |
energy entering the trophic level = energy lost in respiration + energy lost in faces + energy lost in urine + energy in new biomass. |
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How is energy lost in respiration? |
Heat loss |
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How is the energy in the dead remains of plants and animals recovered? |
Decomposers |
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Why do food chains and webs rarely have more than four or five trophic levels? |
Because they transfer of energy to the next trophic level gets less as you go up the food chain. |
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What do pyramids of energy flow show? |
Each bar represents the energy transferred from one trophic level to the next. The bars get smaller as you go further up the pyramids because the transfer of energy from one trophic level to the next trophic level decreases. |
