B1- food chains, energy, biomass and cycles Flashcards Preview

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Flashcards in B1- food chains, energy, biomass and cycles Deck (22)
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1
Q

What are pyramids of biomass?

A

Pyramids of biomass reveal the mass of living material at each stage in a chain. The amount of material and energy decreases from one stage to the next.

2
Q

How does a food chain work?

A

Radiation from the Sun is the ultimate source of energy for most communities of living things. Green plants and algae absorb some of the Sun’s light energy and transfer this energy to chemical energy. This happens during photosynthesis, and the chemical energy is stored in the substances that make up the cells of the plants or algae. The other organisms in a food chain are consumers, because they all get their energy and biomass by consuming (eating) other organisms.

3
Q

What are producers?

A

green plants and algae

they make food by photosynthesis

4
Q

What are primary consumers?

A

usually eat plant material - they are herbivores

for example rabbits, caterpillars, cows and sheep

5
Q

What are secondary consumers?

A

usually eat animal material - they are carnivores

for example cats, dogs and lions

6
Q

What are predators?

A

kill for food

they are either secondary or tertiary consumers

7
Q

What are prey?

A

the animals that predators feed on

8
Q

What are scavengers?

A

feed on dead animals

for example, crows, vultures and hyenas are scavengers

9
Q

What are decomposers?

A

feed on dead and decaying organisms, and on the undigested parts of plant and animal matter in faeces

10
Q

What happens to the available energy absorbed in food chains?

A

Some of the available energy goes into growth and the production of offspring. This energy becomes available to the next stage, but most of the available energy is used up in other ways. For example:
energy released by respiration is used for movement and other life processes, and is eventually lost as heat to the surroundings
energy is lost in waste materials, such as faeces.
All of the energy used in these ways returns to the environment, and is not available to the next stage.

11
Q

Why are most food chains short?

A

There are rarely more than four stages, because a lot of energy is lost at each stage.

12
Q

What does biomass mean?

A

Biomass means the mass of living material at a stage in a food chain. Biomass decreases from one stage to the next, just like the amount of energy.

13
Q

How do you draw a pyramid of biomass?

A

A pyramid of biomass is a chart, drawn to scale, showing the biomass at each stage in a food chain. The bars become narrower as you reach the top. Note that you do not need to draw the organisms but you must draw your pyramid of biomass to scale. Each bar should be labelled with the name of the organism.

14
Q

How does the decay process work?

A

Decay is an essential life process that digests food or waste matter and recycles materials. Materials from living things decay because they are digested (broken down) by microorganisms. These microorganisms cause decay by releasing enzymes that break down compounds to be absorbed by their cells.Bacteria and fungi are the main groups of decomposer.

15
Q

What is a decomposer?

A

An organism that eats dead organisms or animal droppings, and breaks them down into simple materials.

16
Q

What factors affect the rate of decay?

A

moisture
temperature
amount of available oxygen.

17
Q

Why do these factors affect the rate of decay?

A

Microorganisms are more active and digest materials faster when they are in moist, warm and aerobic conditions. They will digest materials more slowly in dry, cold and anaerobic conditions.

18
Q

How do substances in an environment remain stable?

A

Some of the substances released during decay are needed by plants for healthy growth. In a stable community of living things, processes that return substances to the environment (such as decay) are balanced by the processes that remove and use substances. In this way, the substances are continuously recycled.

19
Q

What is the first step of the carbon cycle?

A

Carbon enters the atmosphere as carbon dioxide from respiration (from animals and PLANTS) and combustion (burning).

20
Q

What is the second step of the carbon cycle?

A

Carbon dioxide is absorbed by producers (life forms that make their own food e.g. plants) in photosynthesis . The carbon becomes part of complex molecules (known as carbon compounds) such as proteins, fats and carbohydrates in the plants and algae. These producers then put off oxygen.

21
Q

What is the third step of the carbon cycle?

A

Animals feed on the plants. Thus passing the carbon compounds along the food chain. Most of the carbon these animals consume however is exhaled as carbon dioxide. This is through the process of respiration. The animals and plants then eventually die.

22
Q

What is the fourth step of the carbon cycle?

A

Picture
The dead organisms (dead animals and plants) are eaten by decomposers (who respire) in the ground. The carbon that was in their bodies is then returned to the atmosphere as carbon dioxide. In some circumstances the process of decomposition is prevented. The decomposed plants and animals may then be available as fossil fuel in the future for combustion.

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