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Biology Gcse Full 25-26 > B17-Food Chains/webs And Nutrient Cycles > Flashcards

B17-Food Chains/webs And Nutrient Cycles Flashcards

(110 cards)

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1
Q

What do food chains show?

A

Food chains show the transfer of energy through a food chain.

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2
Q

What type of organism is always the start of a food chain.

A

All food chains begin with an organism that can photosynthesise (i.e. a green plant, algae or cyanobacteria) which makes food (glucose) by photosynthesis.These are known as producers

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3
Q

What is the name given to each level of the food chain?

A

Each level of a food chain is called a trophic level.

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4
Q

How do decomposers form part of some food chains?

A

Decomposers are bacteria and fungi which break down dead plant and animal matter.
Decomposers secrete enzymes onto the surface of the dead organisms
The matter is broken down into soluble food molecules, which are then absorbed into the microorganism by diffusion.

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5
Q

What type of consumer is the organism that eats the producer?

A

Primary consumer

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6
Q

What type of consumer is the organism that eats the primary consumer?

A

Secondary consumer

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7
Q

What type of consumer is the organism that eats the secondary consumer?

A

Tertiary consumer

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8
Q

What are apex predators and give an example.

A

Apex predators are carnivores with no predators. You will find them at the top of a food chain e.g. killer whale

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9
Q

What type of consumer eats the tertiary consumer

A

Apex predators

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10
Q

Distinguish between predators and prey

A

Apredatoris an animal that hunts and eats other animals, and thepreyis the animal that gets eaten by the predator.

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11
Q

List some key adaptations of good predators

A

Camouflage, speed, agility, sharp claws and teeth, stealth, enhanced senses, monocular vision etc.

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12
Q

List some key adaptations of prey animals

A

Camouflage, warning colouration, mimicry, speed, agility, binocular vision, protective body armor, group defensive, chemical defences

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13
Q

What is the difference between a food chain and food web?

A

A-food web is a network of interconnected food chains.
They also show interdependence- how the change in one population can affect others within the food web.

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14
Q

Describe simply what the water cycle is.

A

The water cycle is the continuous movement of water between the atmosphere, land, oceans, and living organisms.

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15
Q

List the main stages of the water cycle

A

Evaporation, condensation, (cooling), precipitation, percolation, transpiration & respiration

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16
Q

Describe the process of evaporation in the water cycle.

A

Evaporation is the process by which water from bodies of water, such as rivers, lakes, and oceans, is heated by the sun and changes from liquid to water vapor, rising into the atmosphere.

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17
Q

What is condensation in the context of the water cycle?

A

Condensation is the process by which water vapor in the atmosphere cools and changes back into liquid water, forming clouds or dew.

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18
Q

Explain how precipitation occurs in the water cycle.

A

Precipitation is the release of moisture from clouds in the form of rain, snow, sleet, or hail, returning water from the atmosphere to the Earth’s surface.

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19
Q

What role do plants play in the water cycle?

A

Plants absorb water from the soil through their roots and release water vapor through a process called transpiration, contributing to the moisture in the atmosphere.

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20
Q

How does human activity impact the water cycle?

A

Human activities such as deforestation, urbanization, and pollution can alter the natural flow of the water cycle by affecting evaporation, transpiration, runoff, and groundwater recharge.

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21
Q

Discuss the importance of the water cycle for ecosystems and human society.

A

The water cycle is vital for maintaining ecosystems, regulating climate, supporting agriculture, and providing drinking water for human populations.

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22
Q

What is the carbon cycle?

A

The carbon cycle is the continuous movement of carbon between the atmosphere, oceans, land, and living organisms.

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23
Q

Describe the process of photosynthesis in the carbon cycle.

A

Photosynthesis is the process by which green plants and algae use carbon dioxide from the atmosphere, along with water and sunlight, to produce glucose and oxygen.

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24
Q

How is carbon dioxide released back to the atmosphere in the carbon cycle?

A

Carbon dioxide is released into the atmosphere through cellular respiration by living organisms, decomposition of organic matter, and combustion of fossil fuels.

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25
What role do decomposers play in the carbon cycle?
Decomposers break down dead organic matter, such as plant and animal remains, releasing carbon dioxide back into the atmosphere through the process of decomposition.
26
Explain the process of combustion in the carbon cycle.
Combustion is the chemical reaction that occurs when fossil fuels, such as coal, oil, and natural gas, are burned for energy, releasing carbon dioxide into the atmosphere.
27
Name the processes that take IN carbon from the atmosphere
Photosynthesis Eating
28
How does the ocean contribute to the carbon cycle?
The ocean absorbs carbon dioxide from the atmosphere, acting as a carbon sink. Carbon dioxide dissolves in seawater and is used by marine organisms for photosynthesis.
29
How does deforestation impact the carbon cycle?
Deforestation reduces the number of trees available to absorb carbon dioxide through photosynthesis. This can lead to an increase in atmospheric carbon dioxide levels and contribute to climate change.
30
What is decomposition?
Decomposition is the breakdown of organic matter by microorganisms into simpler substances.
31
Why is decomposition important in ecosystems?
It is important in ecosystems because it recycles nutrients, releasing them back into the environment for use by other organisms.
32
Describe the factors that influence the rate of decomposition
Factors influencing decomposition include temperature, moisture, oxygen availability, pH
33
Explain how temperature affects the rate of decomposition.
Warmer temperatures generally increase the rate of decomposition by speeding up the activity of decomposer organisms, while colder temperatures slow down decomposition.
34
Discuss the role of moisture in decomposition.
Moisture is essential for decomposition because it allows microorganisms to carry out metabolic processes. Excess moisture can lead to anaerobic conditions, while dry conditions can inhibit decomposition.
35
Explain the importance of oxygen availability in decomposition.
Decomposition is aerobic, meaning it requires oxygen. Adequate oxygen levels promote the activity of aerobic decomposers, while anaerobic conditions can slow down decomposition and produce byproducts like methane.
36
Describe the relationship between pH and decomposition.
Decomposer organisms have optimal pH ranges for activity, and extremes in pH can inhibit their function. Neutral to slightly acidic pH ranges are generally conducive to decomposition.
37
Discuss the potential impact of human activities on the rate of decomposition in ecosystems.
Human activities such as deforestation, pollution, and the use of chemical fertilizers can disrupt decomposition processes by altering soil conditions, reducing biodiversity, and introducing toxins that inhibit decomposer organisms.
38
Describe the pattern of a predator-prey graph
In a stable community the numbers of predators and prey rise and fall in cycles. This is called a cyclical pattern
39
What is biomass?
The amount of biological material in an organism
40
What are decomposers?
Microorganisms that break down dead or undigested organic material. They are important in nutrient cycling
41
What does the arrow in a food chain represent?
The direction of energy flow
42
What are the first 4 stages of a food chain?
Producer -> Primary Consumer -> Secondary Consumer -> Tertiary Consumer 1st Trophic Level -> 2nd Trophic Level -> 3rd Trophic Level -> 4th Trophic Level
43
Why are food chains limited to 4 / 5 trophic levels?
Poor energy efficiency means food chains are limited in size as little energy is passed between stages.
44
What are examples of producers?
Green plants and algae
45
What are the advantages of being a herbivore?
The food does not move, it cannot escape instead it stays still
46
What are the disadvantages of being a herbivore?
Cellulose is very difficult to break down and digest. Herbivores must use a variety of techniques to break down and access the cell contents. They must also eat a lot of plant mass to find and eat enough plant material to provide them with the nutrients they need
47
What are the advantages of being a carnivore?
Food is high in protein and fat and relatively easy to digest
48
What are the disadvantages of being a carnivore?
Food is in the form of other animals, therefore the food must be caught before it can be eaten
49
What are prey?
Consumers which are eaten
50
Explain a predator prey graph:
If there is a plentiful supply of food available (possibly due to a warm summer with lots of rain), the prey animal grow and reproduce successfully, and more offspring survive, so population increases As prey number increases, there is a plentiful supply of food available for the predators, so predators can reproduce successfully, and more offspring survive, so predator population increases The high number of predators eat a large proportion of the prey animals, so the population of the prey falls With fewer prey animals, there is less food for the predators, so the predator population falls as fewer offspring survive Due to a reduction of the population of predators, and the good food supply that results from fewer animals, prey population increases as more offspring survive. The cycle then repeats itself
51
What adds new biomass into an ecosystem?
Photosynthesis
52
What are 2 examples of decomposers?
Bacteria and Fungi
53
Explain the recycling of materials in an ecosystem (decay cycle)
Producers are eaten by consumers. The excretion from the consumers and the bodies of the consumers when they die are broken down by decomposers which digest both the dead animals, plants and waste. They use some nutrients to grow and reproduce but release carbon dioxide, water, and mineral ions as waste products. This returns mineral ions to the soil and carbon to the atmosphere. The mineral ions can then be taken up through plant roots and carbon dioxide into producers during photosynthesis.
54
Explain the process of the water cycle:
The sun heats the earths surface causing water to evaporate from lakes, rivers, and the sea. This forms warm moist air. Water is also released back into the atmosphere through transpiration and respiration in animals As moist air rises it cools, condensing back into a liquid and forming clouds The water droplets are then precipitated back to earth as snow, rain, or hail Surface run off and percolation return water to bodies of water and plants
55
What is percolation?
The movement of water through gaps in soils and rocks
56
How is water released in animals?
Respiration Decay Urine Faeces Sweat
57
How is water released in plants?
Transpiration
58
Explain the process of the carbon cycle:
Carbon is stored as organic compounds in green plants. This carbon can then be transferred to organic compounds in consumers through feeding. It can also be transferred to organic compounds in dead organisms as the plant dies. It may also be directly released back into the atmosphere through respiration Organic compounds in consumers may then be returned directly to the atmosphere through respiration or to organic compounds in a dead organism as the consumer dies Organic compounds in dead organisms may then be released into the atmosphere through decay and decomposition - releasing CO2 through respiration in microorganisms. However, it may become a carbon compound in fossil fuels Fossil fuels can then undergo combustion to return the carbon to the atmosphere in the form of CO2 Photosynthesis from green plants can remove CO2 from the environment, storing it in organic compounds. Carbon dioxide can also dissolve is seas and lakes and be used to make shells in marine life
59
What do plants use carbon from carbon dioxide for?
Making glucose, which can then be used to make starch, proteins, carbohydrates, and lipids
60
What is the word equation for combustion?
Fuel + Oxygen -> Carbon Dioxide + Water
61
Define combustion
a chemical process in which a substance reacts rapidly with oxygen and gives off heat.
62
What does the water cycle do?
Provide fresh water for plants and animals on land before draining into the seas
63
Why are scientists fearful that the carbon cycle may not be able to support itself in the years to come?
Due to increased carbon dioxide emissions by humans
64
What is compost?
A brown crumbly substance produced by aerobic decomposition of waste organic matter and is used as a natural fertiliser as it has high nutrient levels
65
How does making compost kill weed seeds and speed up the decomposition process?
Compost is made by the decomposition of waste organic matter when the decomposers are respiring aerobically. This means they transfer energy to the environment around them which can kill off weed seeds and speed up the decomposition process.
66
What happens when bacteria decompose waste material in anaerobic conditions?
They produce methane
67
What is methane used for?
Fuel
68
How does a biogas generator work
Plant and animal waste is placed in biogas generators. The conditions in the biogas generators are controlled to be kept in anaerobic conditions. Anaerobic decay form bacteria then produces methane which can be used as a fuel
69
How is biogas produced
by anaerobic decay of waste materials
70
What are the advantages of biogas generators?
Produces Methane as a fuel * Reduces amount of waste
71
How to determine the distribution and abundance of species in an ecosystem.
A range of experimental methods using transects and quadrats are used by ecologists
72
What is the mean
Average of all the results
73
What is the mode
Result that appears the most
74
What is median
The middle result
75
How to calc mean
Sum of all/number of thing tested
76
What is a stable community
Biological community where the populations of organisms remain relatively constant over time,and the ecosystem is in equilibrium.
77
What helps keep a community stable?
Plenty of resources (e.g. food, water, shelter) Stable predator-prey relationships No major environmental changes (e.g. drought, pollution)
78
Give an example of a stable community
A tropical rainforest – lots of species live there and conditions (like temperature and rainfall) stay mostly the same
79
What can upset a stable community?
Pollution Climate change Human activity (e.g. deforestation, introducing new species)
80
Why are stable communities important?
They support high biodiversity, meaning lots of different species can survive and thrive.
81
What is a compost
a natural fertiliser for growing garden plants or crops
82
Why do gardeners try to provide optimum conditions
Gardeners and farmers try to provide optimum conditions for rapid decay of waste biological material.
83
Apparatus for required practical 9
Fresh milk pH indicator solution (e.g. phenolphthalein or universal indicator) Test tubes Water baths at different temperatures (e.g. 5°C, 20°C, 37°C, 55°C) Stopwatch Measuring cylinder Thermometer
84
Required practical:Method of Investigating the effect of temperature on the rate of decay using pH change in milk
1. Label two test tubes: • one ‘lipase’ • one ‘milk’ 2.In the ‘lipase’ test tube put 5 cm3 of lipase solution. In the ‘milk’ test tube put five drops of the indicator either Cresol red Use a pipette to add 5 cm3 of milk to the ‘milk’ test tube. Use another pipette to add 7 cm3 of sodium carbonate solution to the ‘milk’ test tube. The solution should be purple. Put a thermometer into the ‘milk’ test tube. Put both test tubes into the water bath. Wait until the contents reach the same temperature as the water bath. Use another dropping pipette to transfer 1 cm3 of lipase into the ‘milk’ test tube. Immediately start timing. 10. Stir the contents of the ‘milk’ test tube until the solution turns yellow. 11. Record the time taken for the colour to change in seconds. Cresol red – the colour will turn from pink (alkaline) to yellow (acidic) 12. Repeat steps 1‒11 for different temperatures of water bath.
85
Safety precautions: for required practical
Use tongs to handle hot test tubes. Don’t consume the milk. Wash hands after the experiment.
86
Practical: Effect of temperature on the rate of decay (using milk pH) Variables
Independent-Temperature Dependent-Rate of decay Control-volume of milk,type of milk,time intervals for checking pH,
87
Why are materials recycled
All materials in the living world are recycled to provide the building blocks for future organisms.
88
Why is the carbon cycle important in an ecosystem?
It returns carbon to the atmosphere as carbon dioxide, so it can be used again by plants in photosynthesis, keeping the carbon levels balanced in the environment.
89
In cycles what happens
many different materials cycle through the abiotic and biotic components of an ecosystem
90
What is the role of microorganisms in cycling materials through an ecosystem?
Microorganisms decompose dead organisms and waste, releasing carbon dioxide into the air through respiration, and returning mineral ions (like nitrates) to the soil for plant use.
91
Rate
1/time
92
What is an ecological pyramid?
A diagram showing the relative amounts of energy, biomass, or organisms at each trophic level.
93
How does climate change disrupt food chains?
Alters habitats, species distributions, and biological processes like migration.
94
What is the role of decomposers in nutrient cycling?
Break down organic material, returning nutrients to soil and CO₂ to the atmosphere.
95
What is meant by the term decay
Break down of tissues in dead plants or animals
96
Equation for photosynthesis
Carbon dioxide +water -> glucose +oxygen
97
Equation for respiration
Glucose +oxygen -> carbon dioxide + water
98
Scavengers definition
Feed on dead animals. For example, crows, vultures and hyenas are scavengers
99
Predator prey graph y and x axis
Y-Population size X-time
100
What happens in a stable community
the numbers of predators and prey rise and fall in cycles.
101
After every trophic level how much of the energy does the next animal get
10%
102
What is a food chain
It is a simple line of organisms, where each organism is eaten by the next one,showing how energy and nutrients pass from one living thing to another
103
What is a food web
A food web is a network of interconnected food chains in an ecosystem.
104
For the required practical why does the pH change?
During the practical, enzymes called lipases break down the lipids (fats) in the milk. This breakdown produces fatty acids, which are acidic. The release of fatty acids lowers the pH, making the milk more acidic. So the pH change (usually a drop) shows that lipids are being digested and broken down.
105
In what conditions is biogas produced
Anaerobic
106
What is carbon in the atmosphere used for in plants
Carbohydrates,fats,proteins which makes up the cells
107
What happens if the decomposers sre working with a lack of oxygen
Carbon in dead remaains can slowly be converted into fossil fuels.
108
How do plants release water
Animals release water in their urine, in their faeces, and as water vapour when they exhale.
109
How do they release water as they breathe
water is lost as water vapour when animals breathe out.
110
How do animals give out water in there faeces?
contains a small amount of water, though its main purpose is removing undigested food, not excretion of water.

Biology Gcse Full 25-26 (12 decks)

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