8 - Ecology and the Environment Flashcards Preview

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Flashcards in 8 - Ecology and the Environment Deck (42)
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1

What is a habitat?

The place where an organism lives

2

What is a population?

All the organisms of one species in a habitat

3

What is a community?

All of the different species in a habitat

4

What is an ecosystem?

All the organisms living in one particular area and all the non-living (abiotic) conditions

5

Describe how to estimate the population size using a quadrat

- Place a 1m2 quadrat on the ground at a random point within the area you're investigating
- Count all the organisms in the quadrat
- Multiply by the total area of the habitat
- Repeat on another area to compare the population sizes
- The sample may not be a representation of the population
- The sample size affects the accuracy of the estimate (the bigger the sample the more accurate)

6

Describe how investigate the distribution of organisms using a quadrat

- Mark out a ling in the area you want to study
- Collect data along all points of the line using quadrats placed next to each other

7

What do food chains show?

-What has been eaten by what in the food chain

8

What is a producer?

The first organism in the food chain who makes their own food using energy from the sun

9

What are consumers?

Organisms that eat other organisms
1 - primary
2 - secondary
3 - tertiary
Each stage is called a trophic level
The arrow always points to what is eating it

10

Pyramids of numbers

- Each bar represents the number of organisms at that stage in the food chain
- Does not have to be a pyramid shape

11

Pyramids of biomass

- Each bar represents the mass of living material at that stage of the food chain (how much they weigh if all put together)
- Almost always a pyramid shape
- e.g. one fox weighs more than 100 flees

12

Pyramids of energy transfers

- Show the amount of energy transferred at each trophic level
- Always the right shape

13

How is energy transferred?

Along a food chain
- Energy from the sun is the source of energy for nearly all life on Earth
-

14

How is energy transferred?

Along a food chain
- Energy from the sun is the source of energy for nearly all life on Earth
- Plants get energy from the sun from photosynthesis
- If a rabbit eats the plant not all of the energy will be transferred as it will be lost as heat
- The amount of original energy from the sun is transferred less and less as you travel up the trophic levels

15

What do food webs show?

How food chains are linked
The arrows point to the what eats the organism

16

Describe the water cycle

- Heat from the sun makes water evaporate from the land and sea turning it into water vapour (also evaporates from plants through transpiration)
- Warm water vapour is carried upwards and as it rises it cools and condenses to form clouds
- Water falls from the clouds as precipitation and is returned to the land and sea
- It is an endless cycle

17

Describe the carbon cycle

- The whole cycle is powered by photosynthesis
- Green pants use the carbon from CO2 to make carbohydrates, fats and proteins
- Eating passes the carbon compounds in the plant along to animals in a food chain or web
- Both plant and animal respiration releases CO2 back into the environment
- Dead plants and animals decompose

18

Describe the carbon cycle

- The whole cycle is powered by photosynthesis
- Green pants use the carbon from CO2 to make carbohydrates, fats and proteins
- Eating passes the carbon compounds in the plant along to animals in a food chain or web
- Both plant and animal respiration releases CO2 back into the environment
- Dead plants and animals are decomposed by bacteria and fungi which releases CO2 back into the environment by respiration
- Some useful plant and animal products (e.g. wood and fossil fuels) are burned (combustion) which releases CO2 back into the environment
- There is a fixed amount of carbon in the world meaning it is all recycled

19

How much nitrogen is in the atmosphere?

78% nitrogen gas which is very unreactive so cannot be used directly by plants and animals

20

Why is nitrogen needed?

For making proteins for growth

21

How to plants get nitrogen?

From the soil

22

What is nitrogen fixation?

Nitrogen fixation is the process of turning N2 from the air into nitrogen compounds in the soil which plants can use

23

Describe the process of nitrogen fixation

Lightning - the energy from the lightning bolt makes nitrogen react with oxygen in the air to give nitrates
Nitrogen-fixing bacteria - in roots (nodules )and soil

24

What bacteria is involved in nitrogen fixation?

Decomposers - break down proteins (in dead animals and plants) and urea (in animal waste) and turn them into ammonia
Nitrifying bacteria - turn ammonia in decaying matter into nitrates
Nitrogen-fixing bacteria - turn atmospheric N2 into nitrogen compounds that plants can use
Denitrifying bacteria - turn nitrates back into N2 gas. This is not beneficial to living organisms

25

How is carbon monoxide poisonous?

- When fossil fuels are burnt without enough air supply they produce carbon monoxide gas
- If CO combines with red blood cells it prevents them from carrying oxygen
- CO is mostly released in car emissions
- Most modern cars have a catalytic converter that turn CO into CO2 which is less dangerous

26

How is acid rain produced?

- By sulphur dioxide
- Burning fossil fuels released CO2 and SO2
- Sulfur dioxide

27

How is acid rain produced?

- By sulphur dioxide
- Burning fossil fuels released CO2 and SO2
- Sulphur dioxide comes from sulphur impurities in the fossil fuels
- When this gas mixes with rain clouds it forms dilute sulphuric acid
- This falls as acid rain
- Internal combustion engines in cars and power stations are the main causes of acid rain

28

How does acid rain kill fish and trees?

- Acid rain causes a lake to become more acidic which kills sensitive organisms and destroys ecosystems
- Acid rain can kill trains as it damages leaves and releases toxic substances from the soil making it hard for the trees to take up nutrients

29

What are greenhouse gases?

Gases that trap in heat energy from the sun and increase the overall temperature of Earth
These gases include water vapour, carbon dioxide and methane

30

What are greenhouse gases?

Gases that trap in heat energy from the sun and increase the overall temperature of Earth
These gases include water vapour, carbon dioxide and methane