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37 Cards in this Set
- Front
- Back
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What does Population mean? |
All the organisms of one species living in the same habitat |
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What does Habitat mean? |
A small part of an ecosystem where a species lives |
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What does Community mean? |
All the populations of organisms that live in the same area or ecosystem |
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What does Ecosystem mean? |
All the organisms and physical factors in a fairly self-contained area such as a lake or desert. |
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Which of the following do plants not compete for? Food Water Space |
Food - they compete for nutrients |
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Why are polar bears white? |
To camouflage them so their prey cannot see them |
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What is the most likely reason why animals in hot climates have larger ears than similar animals in cold climates? |
Big ears lose heat quickly, while small ears lose heat slowly |
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What is the most likely reason why wasps and bees have black and yellow stripes? |
The stripes warn other animals that wasps and bees are dangerous |
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Plants compete with each other for: |
CO2, mineral ions, light and water |
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Organisms that are tolerant to high levels of salt, high temperatures or high pressures are called: |
extremophiles |
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Sampling |
In order to measure population size, we need to calculate the number of individuals of that species in a given area. it is not possible to count the whole population, so the number in a small area is counted and then the population size of the whole area can be estimated. |
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Why do we sample randomly and what is random sampling? |
We sample randomly to avoid bias. We place the quadrats at co-ordinates on a grid. We obtain the co-ordinates using a random number table or the random button on the calculator. |
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Give a few factors that could effect the distribution of plants in a certain area. |
temperature, enclosed/open areas, shade, amount of noise/pollution/movement, wildlife. Also Moisture/damp levels, trampling, protection, mowing - longer grass. |
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What are abiotic factors? |
Physical factors |
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Examples of Abiotic factors |
Light Intensity Soil pH Soil Mineral content Temperature Moisture Levels Wind Intensity and direction Carbon dioxide levels for plants Oxygen levels for aquatic organisms |
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What are Biotic factors? |
Living factors |
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Examples of Biotic factors |
New Predators arriving Availability of food New Pathogens (diseases) One species outcompeting another |
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What is intraspecific competition? |
Competition between the individuals of the same species is called Intraspecific competition eg/ fighting for mates |
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What is Interspecific competition? |
Competition between different species is Interspecific competition eg/ different plants competing for light. |
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Why is Intraspecific competition more likely? |
Because animals try to avoid competition with other species. |
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What is Feeding? |
Plants, animals and decomposers continually recycle the same nutrients through the ecosystem |
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Interaction with the environment: |
Plants absorb mineral ions, carbon dioxide and water. They give off water vapour and oxygen. Animals use materials from the environment to make shelters. All organisms give off heat. |
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What does competition mean? |
Fighting for resources |
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What would happen if an organism fails to obtain all the vital resources that it needs? |
It would die, or fail to thrive or reproduce. |
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If the population size of an organism had the experience of vital resources becoming more plentiful....... |
The population size would expand and become larger, as there is more resources supporting the species. |
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Food webs: |
Are more realistic food chains. In nature, it is very rare to find an organism that has only one food source, or is the food source for only one animal. Food webs are lots of food chains all put together. |
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Example of a Producer: |
Grass Makes food from the sun using photosynthesis |
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Example of a Primary Consumer: |
Cow Gains energy by eating producers; usually herbivores |
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Example of a Secondary Consumer: |
Human: Gains energy by eating Primary Consumers; usually carnivores/ herbivores |
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Pyramid of Numbers: |
The numbers of organisms in a food chain can be represented graphically in a pyramid - “pyramid of numbers”. |
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What does each bar represent? |
The number of individuals at each trophic level (feeding level) in the food chain. |
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What does trophic level mean? |
Feeding level - each stage of the food chain |
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Why is a strange shape obtained in a pyramid of numbers occasionally? |
If there is one large producer such as an oak tree. |
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Pyramid of Biomass |
A more accurate indication of how much energy is passed on at each trophic level. |
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What is Biomass? |
Is the mass of living material in each organism multiplied by the total number of organisms in that trophic level. The Biomass in each trophic level is always less than the trophic level below. |
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What is the 10% rule?
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Only about 10% of the energy consumed by one trophic level is turned into new organism available for the next trophic level. |
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What happens to the 90%? |
- Some parts of the plants are not eaten eg/ roots, bones - Some parts are not digested so are not absorbed, so are egested as faecus. - Some of the materials form excretory products eg/lost in urine - Some of the materials are respired to release energy eg/ for movement and maintaining body temperature, with loss of carbon dioxide and water. |
