Ecology - (A)biotic factors and Food Chains 194-198 Flashcards
what is a hibitat
the place where an organism lives
what is a population
all the organisms of one species living in a habitat
what is a community
the populations of different species living in a habitat
what are abiotic factors
non-living factors of the environment
what are biotic factors
living factors of the environment
what is an ecosystem
the interaction of a community of living organisms (biotic) with the non-living (abiotic) parts of their environment
what do plants need from their environment to survive
3 points
1) light
2) space
3) water and mineral ions from the soil
what do animals need from their environment to survive
3 points
1) space (territory)
2) food and water
3) mates
what is interdependence
where species in a community depends on different species for things like food, shelter, pollination, and seed dispersal
what happens if there’s a major change in an ecosystem
2 points
1) it can have a knock on affect on all things in the ecosystem
2) for example if one species is removed from it, it can mean other species numbers could increase or decrease
what are stable communities
2 points
1) communities where all the species and environmental factors are in balance so the population sizes are roughly constant
2) tropical rainforests and ancient oak woodlands are stable communities
what are some examples of abiotic factors
7 points
1) moisture level
2) light intensity
3) temperature
4) carbon dioxide level
5) wind intensity and direction
6) oxygen level
7) soil pH and mineral content
how can changes in abiotic factors affect populations
3 points
1) a change in the environment could be and increase or decrease of an abiotic factor, this changes the sizes of populations in a community
2) this means it can also affect the population sizes of other organisms that depend on them
3) for example animals that depend on plants for food would be affected by a decrease in a plant population
what are some examples how changed in abiotic factors affect plant populations
4 points
1) a decrease in light intensity, temp, or level of CO2 could decrease the rate of photosynthesis of a plant
2) this could affect plant growth and cause a decrease in the population size
3) a decrease in mineral content of the soil could cause nutrient deficiencies
4) this could also affect plant growth and cause a decrease in the population size
what are some examples of biotic factors
4 points
1) new predators
2) competition - one species may outcompete another so the numbers are too low to breed
3) new pathogens
4) availability of food
how can changes in biotic factors affect populations in a community
2 points
1) a change in the environment could be the introduction of a new biotic factor
2) these changes can affect the sizes of populations in a community which can have knock-on effects because of interdependence
what are some examples of how biotic factors affect populations
2 points
1) a new predator could cause a decrease in the prey population
2) red and grey squirrels live in the same habitat and eat the same food, grey squirrels outcompete red squirrels so red squirrel population size decrease
what are some structural adaptations of animals
4 points
1) structural features are features of an organisms body, like shape or colour
2) for example arctic foxes have white fur and are camouflaged against the snow - this helps them avoid predators and sneak up on prey
3) animals that live in cold places like whales have a thick layer of blubber and a low surface area to volume ratio to help them retain heat
4) animals that live in hot places like camels have a thin layer of fat and large surface area to volume ratio to help them lose heat
what are functional adaptations
3 points
1) things that go on inside an organism’s body that can be related to processes like reproduction and metabolism
2) for example desert animals conserve water by producing very little sweat and small amounts of concentrated urine
3) brown bears hibernate over winter, they lower their metabolism which conserves energy so they don’t have to hunt when there’s not much food around
how are microorganisms adapted
2 points
1) some are known as extremophiles - they’re adapted to live in very extreme conditions
2) for example some can live at high temperatures (like in volcanic vents) and others can live in places with high salt concentrations (like salt lakes) or at high pressures (like deep sea vents)
what is the order of food chains
4 points
1) producers (usually green plants or algae)
2) primary consumers
3) secondary consumers
4) tertiary consumers
how is energy transferred in food chains
4 points
1) starting with producers which make their own food using energy from the sun, making glucose by photosynthesis
2) when they make glucose some of it is used to make other biological molecules
3) these molecules are the plant’s biomass - which can be thought of as energy stored in a plant
4) energy is transferred through living organisms in an ecosystem when organisms eat other organisms
how do predator-prey cycles work in a stable community
4 points
1) the population of any species is limited by the amount of food available
2) if the population of prey increases, so will the population of the predators
3) as the population of predators increases the numbers of prey decreases this continues in a cycle
4) predator-prey cycles are always out of phase with each other because it takes a while for one population to respond to changes in the other population
