Biodiversity & The Distribution Of Life Flashcards
What is meant by species ?
An organism which reproduces with its own kind and is capable of producing fertile offspring
What is meant by an ecosystem ?
A natural biological unit of the environment which consists of all the organisms living in a particular area and the non-living components with which the organisms interact
What does an ecosystem contain?
One or more habitats
What is meant by habitat ?
The place where an organism lives
What is meant by community ?
All organisms of all species in a particular area
What is meant by population?
Total number of organisms of one species in a particular area
What is meant by niche ?
An organisms ecological niche is the role that it plays within the community of an ecosystem. This includes the use it makes of the resources in the ecosystem and the interactions with other organisms in the community.
What are biotic factors ?
Living factors that can affect the distribution of organisms
Give 4 examples of biotic factors?
Predators
Disease
Food
Grazing
What are abiotic factors?
Non-living factors that can affect the distribution of organisms
Give 4 examples of abiotic factors ?
Light intensity
Moisture level
pH
Temperature
Apart from biotic and abiotic factors, what else can affect biodiversity ?
Human influences
Describe grazing in grasslands ?
Natural grasslands normally contain a rich variety of plant species ; some types of grass are vigorous and show more growth, whilst others are more delicate and sensitive to grazing.
What is predation?
A biotic factor that affects the number of both the population of a prey animal and the population of its predator because a delicate balance exists between the two.
What is a predator ?
An animal that hunts and kills other animals for food.
What is a prey?
An animal that is hunted and killed for food.
How are predator prey relationships best described in terms of their population numbers?
In a graph
Describe stage 1 of the predator prey relationship cycle ?
Prey population increases
Describe stage 2 of the predator prey relationship cycle ?
Predator population increases (as more food)
Describe stage 3 of the predator prey relationship cycle ?
Prey population decreases (because of more predators)
Describe stage 4 of the predator prey relationship cycle ?
Predator population decreases (less food)
Describe stage 5 of the predator prey relationship cycle ?
Prey population increases
What is biodiversity ?
The total variation that exists among all living things on earth
What does biodiversity include ?
The variation found between different species and the variation found within the same species
What are human influences ?
The effect of human activities on the environment
Give 2 examples of human influences ?
Air/water pollution
Deforestation
What causes acid rain?
The combustion of coal by electricity- generating power stations which produce sulfur dioxide and nitrogen oxides which combine with water to form acids
What species of animal in mainly affected by acid rain falling into rivers and lochs ?
Fish species
Give an example of a fish species that is affected by a decrease in pH to a large extent ?
Trout
Give an example of a fish species that is affected by a decrease in pH to a small extent ?
Eel (can tolerate more acidic conditions)
What is thermal pollution and how is it caused ?
When the water is returned to the river and it is considerably warmer
Thermal pollution is caused by some types of electricity- generating power stations using local river water as a coolant
What other abiotic factor is affected by an increase in water temperature?
Oxygen concentration
What is a biome ?
A region of the planet that has a characteristic climate, type of vegetation (flora) and community of animals (fauna)
What do organisms living in a particular biome have?
Adaptations allowing them to survive the climatic conditions of that regions
What is the distribution of biomes mostly influenced by?
Temperature and rainfall
Describe freshwater biome?
About 3% of earths water is freshwater
Included water locked up in the ice caps and trapped in rocks and soil
Only tiny fractions is surface water in forms of rivers, lakes and swamps
Describe marine biome ?
Salt water
Cover 71% of earths surface
Describe desert biome ?
Dry and hot
Less than 250mm of rainfall per year
Largest desert is the Sahara in North Africa
Describe the forest biome ?
Dominated by trees
Divided into tropical and temperate forest
Describe grassland biome ?
Dominated by grasses and shrubs
Divided into tropical (Savannah) and temperate grassland
Describe the tundra biome ?
Surrounds north Arctic and south Antarctica poles and found in mountainous areas
What is the distribution of lichens influenced by?
Human activities
What is a lichen formed from?
A mutualistic relationship between an algae and a fungus
What do different species of lichen vary in ?
Their sensitivity to sulfur dioxide
What can only crusty lichens tolerate?
Tolerate high levels of sulfur dioxide concentrations in the atmosphere
What can lichens be used to do ?
Indicate the levels of sulphur dioxide pollution in the atmosphere
What can types of invertebrates be used as ?
An indicator species to indicate levels of pollution so in rivers
What is meant by biodiversity ?
Variety of living organisms in a particular ecosystem
Give an account of the factors that define an organism niche
What resources it uses What organisms it interacts with What it feeds on What feeds on it What it adds to the environment
