Ecology

• Ecosystem: the interaction between a community (the living, biotic part) and the non-living (abiotic) parts of the environment
• Population: a number of individuals of the same species living in the same area at the same time
• Community: multiple populations (of different species) living and interacting in the same area
• Competition: If a group of organisms all need the same resource in order to survive and reproduce, but there is a limited amount of the resource available, they are said to compete for the resource
• intraspecific competition is between members of the same species
• interspecific competition is between members of different species
• Plants require light for photosynthesis which helps them grow
• plants require space above and below soil to maximise sunlight and help absorb water and mineral ions
• Plants need water and mineral ions (to make protein and chlorophyll)
• Animals need food to grow and reproduce
• animals need mates to reproduce and pass on genes
• animal compete for territory to provide them with water, food, shelter and mates
• interdependence is when each species depends on other species for food, shelter, pollination, seed dispersal
• An abiotic factor is a non-living factor
• light intensity is an abiotic factor which is needed by plants for photosynthesis
• temperature is an abiotic factor which affect the rate of photosynthesis in plants
• moisture levels is an an abiotic factor which both plants and animals require to survive (water)
• soil ph and mineral content is an abiotic factor where different species are adapted to different soil ph and mineral content
• wind intensity and direction is an abiotic factor that affects transpiration rate in plants. This affects photosynthesis as well as it ensures water and mineral ions are transported to leaves
• carbon dioxide levels in plants is an abiotic factor which plants need to carry out photosynthesis
• oxygen levels for aquatic animals is an abiotic factor where some aquatic animals can only survive in high oxygen concentrations
• A biotic factor is a living factor
• Abiotic factors include light intensity, temperature, moisture levels, soil pH and mineral content, wind intensity, carbon dioxide levels and oxygen levels.
• biotic factors include availability of food, new predators, new pathogens and competition
• more availability of food means higher chance of surviving and reproducing, meaning their populations increase
• new predators can make an ecosystem unbalanced by decreasing prey population
• new pathogens can decrease or wipe out populations as species have no immunity against it
• some species can outcompete the other if they are better adapted and take another species' resources. this can wipe out a species
• Organisms have adaptations that enable them to survive in the conditions in which they normally live.
• adaptations can be structural, behavioural or functional
• structural: physical part or feature of an organism
• behavioural: the way an organism behaves
• functional: biological processes within the organism
• Animals in cold regions have a small surface area : volume ratio to minimise heat loss and a thick layer of fat or fur which insulates against the cold. These are structural adaptations
• Some desert animals have specially adapted kidneys which produce very concentrated urine, helping the animal to retain water – this is a functional adaptation
• Some desert animals have structures to increase their surface area : volume ratio to aid heat loss – these are structural adaptations
• Some desert animals are only active in the early mornings, late evenings or at night when it is cooler – this is a behavioural adaptation
• Organisms that can live in extreme environments are called extremophiles
• the larger the animal, the smaller its surface area : volume ratio.
• Producers produce their own food using energy from the Sun