Ch: 4,5,6 Ecology Flashcards
Biosphere
The part of the earth where life can exist
Ecosystem
The community of organisms that interact with their environment
Habitats
A place where an organism lives
Population
Members of the same species living in a habitat together
Community
All the different populations in an area
Abiotic factors
Non living factors that affect an organism
Biotic factors
living factors that affect an organism
Climatic factors
Weather conditions that affect an organism
Ex: rainfall, wind, temperature, humidity
Edaphic Factors
Factors relating to the soil and the geology of the land that affect living organisms
Examples of biotic factors
Food, competition, predation, parasitism and human activity
Main source of energy?
The sun
Producers
The green plants that make their own food using energy from the sun
Consumers
Organisms that feed on other organisms
Food chain
A flow diagram that shows how food/energy is passed through a series of organisms in a community
Trophic level
The position an organism occupies in a food chain
The energy flow - where does the energy go
10% is transferred through organisms
90% is used for growth, reproduction, movement and heat
Pyramid of numbers
A diagram that represents the numbers of organisms at each trophic level in a food chain
Types of pyramid of numbers
Upright, inverted, partially upright and partially inverted
Limitations of pyramid of numbers
-The size of the organisms is not considered
-Some numbers are soo great the pyramid cannot be drawn to scale
Niche
The functional role an organism plays in its habitat
Why organisms live in populations?
The habitat provides food and shelter
Safer for individuals
Breeding purposes
What controls the size of a population?
Competition
Predation
Parasitism
Symbiosis
Competition
When two or more organisms fight for a resource that is in short supply
Resources that animals fight for?
Food
Water
Shelter
Territory
Mates
Resources plants fight for?
Light, water, space, minerals
Two types of competition
Contest and scramble
Contest competition
The direct fight between two organisms for a resource that is in short supply and there is only one winner
Scramble competition
The struggle amongst a number of organisms for a resource in short supply and all competing individuals get some of the resource
Predation
The catching, killing, and eating of another organism
Predator
The organism that hunts, kills and eats its prey
Prey
The organism that is eaten by the predator
Pros of predation:
- stabilises the community
- controls the number of herbivores - prevent overgrazing
- eliminate the weaker prey and unwanted species
Examples of adaptations in predators
- Hawks have excellent eyesight
- ladybirds have strong mouth parts
- cheetahs run very fast
Examples of adaptations in prey:
Frogs are well camouflaged
Zebras have stripes- hard to identify them
Ladybirds contain large amounts of formic acid so they are unpalatable to taste
No. Of predators increase due to:
-immigration
-lots of mates
-plenty of food
No. Of predators decrease due to:
- emigration
- disease
- prey numbers reduce
Symbiosis
Where two organisms of different species have a close, specific relationship with each other where at least one of them benefits
Mutualism
When both organisms benefit from a symbiotic relationship
Parasitism
Where one organism (aka parasite) lives in or on another organism (aka host) and the host is harmed
Population dynamics
The study of the changes that occur in a population and the factors that cause these changes
Population changes due to :
- Birth and death
- Emigration and immigration
- Effect of other species in the form of competition, predation and symbiosis
High DR is important as:
- protects the stock of food
- eliminates the less adapted organisms/ survival of the fittest
Factors affecting human population;
War, disease, famine and modern medicine
Carbon cycle
Process through which elemental carbon is exchanged between living organisms and their environment
How CO2 is removed from the atmosphere ?
- photosynthesis
- formation of fossil fuels
How CO2 is released or returned back into the atmosphere?
respiration
Decomposition
Combustion
Role of plants in the carbon cycle
Remove co2 through photosynthesis
Return co2 through respiration
Role of animals in the carbon cycle
Obtain carbon from eating plants
Release co2 through respiration
Role of microorganisms in the carbon cycle
Returns carbon back into the environment when they break down organisms
Decomposer
An organism that feeds off and breaks down dead organisms
Global warming
The warming of global temperatures due to increase in co2 levels
Reasons for co2 levels increase
Increased usage and combustion of fossil fuel
Deforestation
Greenhouse gas
Group of gases that are able to trap heat in the atmosphere, keeping the earths surface warmer than it should be
Nitrogen cycle
Process through which elemental nitrogen is exchanged between living organisms and their environments
Nutrient recycling
The way in which elements are exchanged between the living and the non living components of an ecosystem
Nitrogen fixation
The conversion of nitrogen gas to nitrates
Nitrification
Conversion of ammonia to nitrites and then to nitrates
Pollution
Any harmful addition to the environment
Pollutants
Substances that cause pollution
Effects of pollutants
Agriculture- slurry and fertiliser - algal blooms and eutrophication
Industrial - sulphur dioxide - forms acid rain
Domestic - plastic bags - litter/ non biodegradable
Eutrophication
A process where water receives too many nutrients that stimulate excessive algal growth
Eutrophication
A process where water receives too many nutrients that stimulate excessive algal growth
Conservation
Protection and wise management of natural resources and the environment
Conservation
Protection and wise management of natural resources and the environment
