Life On Earth Flashcards
Define consumer
An organism which consumes other organisms for food
Define producer
An organism that can produce its own food
Definition of species ?
A group of organisms which can be interbred and produce fertile offspring
Definition of biodiversity?
The range of species within an ecosystem
Definition of population?
A group of organisms of the same species
What is a food chain ?
A diagram which shows a simple feeding relationship between organisms
What is a food web?
A diagram which Shows the interconnection of food chains
What is an ecosystem ?
Consists of all the organisms living in a particular habitat and the non living components with which the organisms interact
What is a biological niche ?
A niche is the role that an organism plays within a community
What is interspecific competition ?
Interspecific competition occurs amongst individuals of different species for one or a few resources they require
What is intraspecific competition?
Intraspecific competition occurs amongst individuals of the same species and is for all resources required
What are producers and consumers ?
Producer: An organism that can make its own food (eg plants)
Consumer: An organism that consumes another organism
What is a pyramid diagram?
Pyramid of numbers - a diagram which represents the number of organisms at each level in a food chain
What is a pyramid of energy?
A diagram showing the energy contained within organisms at each level in a food chain
What is a decomposer?
Microorganisms which breakdown organic matter (eg dead bodies, faeces etc)
What are biotic factors?
Any living component that affects another organism (eg plants disease etc)
Examples of biotic factors
Disease Availability of food Predation Grazing Competition for food
Examples of abiotic factors
Light intensity
Soil pH
Soil moisture
Soil temperature
What are abiotic factors ?
They are non living components that affect living organisms.
Eg sunlight,soil composition ,temperature
How can energy be lost in ecosystems?
Uneaten/undigested
Used in respiration to release energy for movement
What is an indicator species?
A species which indicates the level of pollution in an ecosystem
What are the 2 stages of photosynthesis?
1=light reactions
2=carbon fixation
Light reactions summary
During the light reactions light energy from the sun is trapped by a green pigment called chlorophyll in the chloroplast. The light energy is converted into chemical energy which is used to generate ATP. Water is split to produce hydrogen and oxygen. Hydrogen is used in the second stage of photosynthesis and oxygen diffuses out
Light reactions word equation
Light energy
Carbon dioxide+water—>sugar+oxygen
Carbon fixation summary
Carbon fixation uses hydrogen and ATP from the light reactions to convert carbon dioxide from the air into sugar. The carbon fixation reactions are catalysed by enzymes; this means that the rate of carbon fixation is affected by temperature
Carbon fixation word equation
Enzymes
Hydrogen+carbon dioxide——>sugar
ATP
(Hydrogen from stage 1)
Limiting factors of photosynthesis
Light intensity, carbon dioxide concentration and temperature
Photosynthesis word equation
Light energy
CO2+water————>sugar+oxygen
Why do plants require nitrates?
To make proteins
Percentage increase?
Find difference between 2 numbers and divide by original number
Percentage decrease?
Find difference between 2 numbers and divide by original number
