B4 Flashcards
How does Carbon in the atmosphere enter food chains?
Carbon in the atmosphere form carbon compounds in plants and are consumed by animals.
Fill in the blanks: Carbon is removed from the __ by __ to be used in photosynthesis to make glucose
atmosphere, producers
“When organisms die, the matter in their bodies is recycled for other purposes.” What does this describe?
The Carbon Cycle
Name a source of carbon entry into the atmosphere.
Fossil Fuels
List all examples of nitrogen transferred In the Nitrogen cycle.
- Lightning strikes soil
- Animals eat plant
- Animals Decompose
- Plants absorb nitrogen in soil through roots
What does the bacteria ‘decomposers’ do?
They decompose protein and urea, then turn them into ammonia, which goes on to form ammonium ions.
What bacteria in the nitrogen cycle turns atmospheric N2 into nitrogen compounds?
Nitrogen-fixing bacteria.
What is the function of nitrifying bacteria?
They turn ammonium ions in decaying matter into nitrates.
Describe how denitrifying bacteria works and where they are usually found.
They turn nitrates back into N2 gas. They are often found in waterlogged soils.
Besides from living in the soil, where else do nitrogen-fixing bacteria live?
Others live in the nodules of the roots in legume plants
List the four processes in the water cycle.
Evaporation, Transpiration, Condensation, Precipitation.
List the main types of decomposers.
Bacteria and Fungi.
What factors affect the rate of decomposition and why?
- Oxygen Availability - aerobic respiration for more energy
- Temperature - Decomposers contain enzymes which digest waste material
- Water content - Decomposers need water to survive, usually in moist conditions
How do you calculate the rate of decomposition?
Divide amount of product by time (usually days).
Explain how temperature affects the rate of decomposition.
Most decomposers work best in warm conditions, the rate of decomposition is highest at around 50 degrees celcius. Decomposers contain enzymes which digest the dead/ waste material.
What is meant by the term ‘community’ in the organisation of ecosystems?
All the organisms (different species) living in a habitat.
What is an ecosystem?
An ecosystem is made up of living organisms (biotic) and non-living (abiotic) parts.
What do animals in an ecosystem usually compete for?
Food, water, mates, territory.
What do Plants in an ecosystem usually compete for?
Light, space, water, minerals
List 4 abiotic factors that affect communities.
Temperature, Moisture level, Light intensity, pH level.
Give 2 examples of biotic factors that affect communities.
Availability of food, number of predators.
Provide examples of ways where species rely on each other.
Pollination, Shelter, Food, Seed dispersal
Explain the difference between parasitic and mutualistic relationships.
Parasites live off a host - they take what they need and don’t give back (Win-Lose relationship)
Mutualistic relationships benefit both organisms. (Win-Win relationship)
A community is stable when:
Species are balanced
Population size stays constant,
Environmental factors balanced.
What is the function of food chains?
They show the feeding relationships within a community.
What are each stage of the food chain called?
A trophic level.
Name the major trophic levels in chronological order.
Producers, Primary consumers, Secondary Consumers, Tertiary Consumers
Define the term ‘biomass’.
Biomass is the total mass of living material in an organism multiplied by the number of organisms.
What is the function of food webs?
Food webs show how food chains are linked.
How could you calculate the efficiency of energy transfer?
Efficiency = biomass for next level/ biomass from last level x 100%
Give two ways that biomass is lost between trophic levels.
Any two from: Respiration, excretion, egestion.
What is egestion?
Egestion is getting rid of undigested food.
In food chains, biomass is lost between different trophic levels.
One reason for this is the release of undigested food from the body.
Which term is used to describe this release?
Egestion.
