Ecology and the Environemnt

Question 1

What is population?

Answer 1

The number of organisms of one species in a habitat.

Question 2

What is a community

Answer 2

All the different species in a habitat

Question 3

What is a habitat

Answer 3

The space or area in which an organism lives.

Question 4

What is an ecosystem

Answer 4

An area where non- living and living things interact together.

Question 5

How can you estimate the population size of an organism in different areas?

Answer 5

• Randomly throw a quadrat on the ground.
• Count all the organisms within the quadrat.
• Repeat 5 times and find the mean.
• Multiply this number with the size in m^2 of the investigated area.
• Repeat for other areas.

Question 6

How can quadrats be used to sample the distribution of organisms in their habitats?

Answer 6

Mark out a line along the area you want to investigate.

Using quadrats, collect data along the line.

Question 7

What are producers

Answer 7

Organisms that make their own food

Question 8

What are primary consumers

Answer 8

Organisms that usually eat plant material (herbivores)

Question 9

What are secondary consumers

Answer 9

Organisms that usually eat animal material (usually carnivores)

Question 10

What are territory consumers

Answer 10

Carnivores, but at the top most level in the food chain

Question 11

What are decomposers

Answer 11

Mainly fungi and bacteria. They break down dead animal and plant material and use the nutrients from it by respiration.

Question 12

What is a food chain

Answer 12

A simplistic representation of a situation in an ecosystem.

Question 13

What is a food web?

Answer 13

A complex representation of a situation in an ecosystem that takes into account the different feeding preferences of animals.

Question 14

What are pyramids of numbers

Answer 14

A pyramid drawn to scale to show the population of each organism.

Question 15

What are pyramids of biomass

Answer 15

A pyramid drawn to give a more accurate indication of how much energy is passed on at each tropic level.

Question 16

What is biomass?

Answer 16

The dry mass of living material in each organism.

Question 17

What are pyramids of energy transfer?

Answer 17

A pyramid that represents estimates for energy values with producers in the lower layer up to the consumer in the top layer.

Question 18

What happens when one thing consumes another in terms of energy?

Answer 18

The substances within it (e.g. Fat) get transferred to the consumer.

Question 19

Pyramids have wide bases and eventually decrease in width as energy has been lost. Why is this?

Answer 19

• material is not eaten by the consumer?
• material is not digested by the consumer, and is therefore passed out as waste.
• energy is used by the consumer for movement
• energy is used for metabolic processes (e.g. Respiration)
• energy is used in generating heat
• energy is lost in urine.

Question 20

What is evaporation and how does it contribute to the water cycle?

Answer 20

This happens to water on wet surfaces and bodies of water and turns it into water vapour which goes in to condense to clouds.

Question 21

What is transpiration and how does it contribute to the water cycle?

Answer 21

The loss of water from plants as it evaporates from the surface of vegetation. It forms water vapour which then condenses to form clouds.

Question 22

What is condensation and how does it contribute to the water cycle?

Answer 22

Water vapour in the atmosphere condenses to from clouds, fog, frost etc.

Question 23

What is precipitation and how does it contribute to the water cycle?

Answer 23

Water vapour is held in the formation of clouds, fog and frost. Some falls into the ground and forms rivers and streams or is taken up by plants.

Question 24

What is combustion and what is its relation to the carbon cycle?

Answer 24

The burning of materials derived from plants, which releases co2 into the atmosphere. This is then used by plants to photosynthesise.

Question 25

What is photosynthesis and what is its relation to the carbon cycle?

Answer 25

A metabolic reaction in green plants that uses light energy to make energy. It takes in co2.

Question 26

What is respiration and what is its relation to the carbon cycle?

Answer 26

A metabolic reaction that releases energy and carbon dioxide gas. The energy released is used for growth and repair.

Question 27

What is decomposition and what is its relation to the carbon cycle?

Answer 27

A process where bacteria and fungi break down large molecules into smaller molecules when organisms dies. They respire and produce co2.

Question 28

What do nitrogen fixing bacteria do in the nitrogen cycle?

Answer 28

They convert nitrogen in the air into nitrates so that plants can use them to make amino acids and proteins.

Question 29

What do decomposers do in the nitrogen cycle ?

Answer 29

Break down dead animal and plant matter, releasing nitrogen as ammonia.

Question 30

What do nitrifying bacteria do in the. Nitrogen cycle?

Answer 30

Convert ammonia into to nitrites, nitrites into nitrates and or ammonium ions.

Question 31

What do denitrifying bacteria do in the nitrogen cycle?

Answer 31

Reconvert nitrates back into nitrogen gas = decreasing valuable resources in the soil.

Question 32

What are the biological consequences of sulphur dioxide?

Answer 32

- So2 in combustion of fossil fuels= dissolves in water= acid rain- low pH: fish pop has decreased and sticky mucus on gills= less gas exchange. - acidified lakes= loss of algae in water= alters balance of species. - many trees and plants have died/ had poor growth due to acidic soil. - acid rain= crumbles buildings

Question 33

What are the biological consequences of carbon monoxide?

Answer 33

- car exhausts and cigarette smoke= co= poisonous gas that reduces the blood's oxygen carrying capacity. - prevents formation of haemoglobin= less o2 transported= cell death

Question 34

Give examples of green house gases? (5)

Answer 34

``` Water vapour Carbon dioxide CFC's Nitrous oxides Methane ```

Question 35

How is co2 formed and what is its effect?

Answer 35

Burning of fossil fuels= factories and power stations | Deforestation= less uptake of CO2 and therefore upsets balance between photosynthesis and respiration

Question 36

How is methane formed and what is its effect?

Answer 36

Cattle and other ruminants= digestion= methane Rice paddy fields= produced by bacteria in anaerobic conditions Decay of waste material= methane released

Question 37

How are CFCs formed and what is its effect?

Answer 37

CFC (11)- aerosol sprays= made by humans from fridges and aerosol cans CFC (12)- cooling agent.

Question 38

How are nitrous oxides formed and what is its effect?

Answer 38

Fossil fuels/ motor exhausts= catalytic converters have been fit Nitrogen fertilisers= nitrates in soil are converted to NOx and N2by denitrifying bacteria

Question 39

What is the greenhouse effect?

Answer 39

- Electromagnetic radiation is emitted from the sun into the earth's atmosphere - earth absorbs electromagnetic radiation with short wavelengths and so it warms up. - Heat is radiated from Earth as longer wavelength radiation - sine if this is absorbed by greenhouse gases=warmer * more greenhouse gases= warmer earth*

Question 40

What are the effects of global warming?

Answer 40

- rise in temp= ice caps melting, flooding and sea level rise. -loss of habitat -disruption to food chain as organisms die -migration of animals - desertification - severe climate changes

Question 41

What are the biological consequences of water pollution by sewage?

Answer 41

If sewage enters a lake= increase in nutrients especially as microorganism will break the sewage down to even more nutrients. = increased nutrients stimulate rapid growth and multiplication of algae.

Question 42

What is sewage?

Answer 42

The domestic waste material from human communities. It contains human urine and faeces and phosphates and nitrates.

Question 43

What happens when there is an increase in algae?

Answer 43

There are more life cycles= more deaths. More deaths=more decomposition=more nutrients for microbe respiration. More respiration= more oxygen required= higher BOD. Higher BOD= less oxygen available so aquatic animals suffocate and die. * or more algae= more shade so plants die.

Question 44

What is eutrophication?

Answer 44

The enrichments of the water which can happen due to leached minerals from fertilisers or from sewage.

Question 45

What are the effects of deforestation?

Answer 45

-Leaching: less trees= less water is held back to water runs off, taking mineral ions with it. -Soil erosion: top soil is removed or washed away so soil is directly exposed to wind and rain. -*less trees= loss of soil structure and fertility. Disturbance of water cycle= much more unabsorbed water= flooding and landslides. -imbalance of o2 and co2: less co2 absorbed for photosynthesis and more is released from burning the trees= enhances greenhouse effect Less o2 is produced= respiration problems.

Question 46

What is a greenhouse gas?

Answer 46

Gases that trap heat and contribute to global warming.