Energy and biomass in food chains Flashcards Preview

GCSE Biology B1 > Energy and biomass in food chains > Flashcards

Flashcards in Energy and biomass in food chains Deck (10):

What is the primary source of all energy in biomass (living material)?

The sun, specifically the radiation (light) that stimulates glucose production in green plants and algae through photosynthesis, thus converting light energy into chemical energy
This energy is stored in the substances that make up the cells of the plants


Why is the biomass at each stage less than it was at the previous stage?
How can the biomass at each stage be drawn or represented?

Some materials and energy are lost the the organisms' waste or excrement
Much of the energy from respiration is eventually transferred into the surroundings (through heat loss, etc)
Drawing each stage to scale and making a pyramid


How do living things interact with and influence their environment?

They remove materials from it for growth and other processes, which are then returned either in waste or when it dies and decays


Why do materials decay? What does this do for nearby plants?
What are the optimum (fastest) conditions for decay?

Microorganisms digest them and slowly break them down, releasing substances that plants need to grow
Warm, moist and aerobic (plenty of oxygen)


Describe a stable community

Where the processes that remove materials are balanced by processes that return materials; the materials are constantly cycled


In the carbon cycle, how do green plants and algae use carbon?

They remove it from the environment for photosynthesis in the form of carbon dioxide. The carbon is then used to make carbohydrates, fats and proteins, which make up their bodies. When they respire, some of it becomes CO2 and releases into the atmosphere


In the carbon cycle, how is carbon used by animals?

They eat the plants and algae, and when other animals eat them, some of the carbon becomes part of the fats and proteins that make up their bodies. Respiration releases some as CO2 into the atmosphere.


In the carbon cycle, when plants, algae and animals die, what happens to them and to the carbon?

Some animals and microorganisms feed on their bodies, ingesting the carbon stored in the fats and proteins. They respire, releasing CO2.


Summarise the carbon/energy cycle

By the time the microorganisms and detritus feeders (such as earthworms, who consume decomposing biomass and faeces) have broken down the waste products and dead bodies of organisms in ecosystems and cycled the materials as plant nutrients, all the energy originally absorbed by green plants and algae has been transferred


How can CO2 be released into the atmosphere?

Combustion of wood and fossil fuels