Life on Earth Flashcards
What is Biodiversity?
The variety of plant and animal life in the world or in a particular habitat
What is the problem with deforestation?
Natural resources destroyed, animals become extinct, no oxygen being produced
What is the problem with desertification
No land to grow crops
What are biotic factors?
A biotic factor is a living thing which effects an ecosystem,
What is an abiotic factor?
An abiotic factor is a non living thing which affects and ecosystem
Examples of Biotic factors
Competition, disease, predators, grazing
Examples of abiotic factors
wind speed, pH, concentration of oxygen, light intensity, moisture, temperature
What happens to biodiversity when grazing increases?
Biodiversity increases but when grazing becomes to high it starts to fall again
Explain this graph
An increase in the prey causes and increase in predator as more food is available. The number of prey then decreases causing a decrease in the number of predators
What is a biome?
Biomes are the major ecological systems which can be distinguished by their abiotic factors, flora and fauna
Examples of aquatic biomes
Reef, Loch
Example of terrestrial biomes
Tropical rainforest, temperate grassland
What is an ecosystem?
A biological community of interacting organisms and their physical environment
What is a habitat?
The place where an organism lives
Definition of population?
A group of organisms of the same species
What is a community?
Total of all populations of living organisms
What does the term niche refer to?
The role the living organism plays in its community
Where does all energy come from?
The sun
How do plants capture the energy of the sun?
Through a process called photosythesis
What are the organisms at the bottom of the food chain referred as?
Producers
All other organisms other than producers are referred to as?
A consumer
What does an arrow represent in a food chain?
The flow of energy from one organism to another
How much energy is passed on at each stage of a food chain?
10%
What is the most reliable way to represent feeding relationships in a food chain?
A pyramid of biomass
What are the three main elements in fertilisers?
Nitrogen, Phosphorus and Pottasium
What can be caused by irresposible fertilisation?
Eutrophication
What 4 things do plants compete for?
Sunlight, space, water and minerals from the soil
What 3 things do animals compete for?
Space, food and a mate
What is inter-specific competition?
The competition between different species
What is intra-specific competition?
The competition between the same species
What occurs after high intra-specific competition?
Natural selection
What does the study of an ecosystem involve?
Finding out the types and abundance of living organisms
What is a quadrat used for?
A quadrat marks off a small piece of area and samples the organisms within
Two possible sources of error when using quadrats?
To big a quadrat
Placement of quadrat isn’t random
What is a pitfall trap used for?
To capture small animals
What are 2 possible sources of error with using a pitfall trap?
Lip of trap above soil
The cup is too obvious as there is a lack of leaves
What is a mutation?
A mutation is a random change to the genetic material of an organism
A mutation causes permanent change to the DNA of an organism(it’s). This can alter its - its appearance or functioning of the organism-
Genotype, phenotype
What are mutagenic agents?
An enviromental factor which increases the rate of mutation
What are some examples of mutagenic agents?
Radiation and chemicals
Examples of disadvantageous mutations
sickle cell anaemia and cystic fibrosis
Advantageous mutations are benefical because….
They lead to natural selection
What does variation refer to?
The differences between individuals of the same species
What is an adaptation?
An adaptation is an inherited characteristic that makes an organism well suited to survive in its enviroment
Examples of structural adaptations
Spikes, toughness, fur, blubber fat
Examples of physiological adaptations
poison, smell, camouflage,
Examples of behavioural adaptations
Endurance, food stores, echolocation
What are the two types of behaviour and how do they differ?
Learned behaviour is behaviour they pick up sa they grow older
Innate behaviour is behaviour inherited from their parents and passed through genes
What is imprinting?
An example of learned behaviour which keeps newborn animals close to their parents
What is habituation?
An example of learned behaviour and occurs when an animal after a period of exposure to a stimulus, stops responding
What is natural selction caused by and name 3 examples?
Selection pressures- food, mates, resistance to diseases
What is natural selection?
Natural selection is the survival of those organisms best adapted to their enviroment “survival of the fittest”
What is speciation?
Speciation is 4 stage process which allows the formation of new species.
What are the 4 stages of speciation?
1-Isolation
2-Mutation
3-Natural Selection
4-Time
What two emissions from combustion of fossil fuels lead to acid rain?
Sulphur dioxide and nitrogen oxide
What is a biological indicator?
Indicator species are species that by their prescence, abundance or abscene show the levels of pollution or enviromental quality
What is a pesticide?
A pesticide is a chemical applied to a crop to reduce competition from other organism
What is bioaccumulation?
When non specific pesticides build up in organisms throughout the food chain
What is a biological control?
A natural pesticide
