Systems in balance Flashcards
How are fertile and infertile offspring created?
For an offspring to be fertile the animals need to be the same species, different species breeding will create infertile offspring.
How does an organisms environment affect it?
A species will adapt to its environment to give it a better chance of survival in competing with other species for resources and survival.
What do different organisms compete for?
Animals compete for food, a mate, living space and territory.
Plants compete for light nutrients, water and space.
Why will a change in one species affect others in the same habitat?
Animals are part of food webs, with each being connected to others dependant of them food and resources. This is called interdependence, too big a change to some animals can cause others to over breed or become extinct.
Where do organisms get their energy from?
Plants absorb some of the Sun’s energy for photosynthesis, this energy is then stored in plant’s cells. In an ecosystem this energy will be transferred to animals when they eat these plants and each other. Detritivores and decomposers get their energy from eating dead and waste materials.
How does this energy pass down?
Energy will be passed along food chains as each eats the other but some is wasted. Energy passes out of a chain via heat, waste products and uneaten parts. This means at each stage there is an energy efficiency and at each trophic level animals must eat more of the previous to have enough energy.
How does the carbon cycle work?
Carbon enters the cycle as carbon dioxide from the air. Plants fix this so it can be used and stored by organisms. It is returned to the air by respiration, decomposition (of dead organisms by soil microorganisms) and combustion.
How does nitrogen turn into different forms?
Nitrogen fixing bacteria (leguminous plants) and lightening turn nitrogen from the air into nitrates. This is then used to make protein in plants, and the animals that eat them. It returns to the soil through excretion, death and decay of plants and animals. Denitrifying bacteria turn it back from nitrogen compounds to nitrogen in the air.`
What two ways can we use to measure environmental change?
Living and non-living indicators.
What are examples of living and non-living indicators?
Living- phytoplankton, lichens, mayfly nymphs.
Non-living- nitrate levels, temperature, carbon dioxide levels
