3.5 population size and ecosystems 2

Question 1

What is the definition of biodiversity?

Answer 1

The number of different species and individuals within each species in a given place at a given time

Question 2

What are the steps of the capture-recapture technique?

Answer 2

1) Capture a sample. Count, mark, and release them
2) Recapture and count a second sample
3) count total number of recaptured organisms

Question 3

What are the issues with the capture-recapture technique?

Answer 3

-trap has to be humane
-marking method can’t damage or visibly mark animals
-doesn’t account for immigration, emigration, births, and deaths

Question 4

What is the equation for capture-recapture?

Answer 4

(1st capture x 2nd capture) / recapture

Question 5

What are the steps for kick sampling?

Answer 5

1) Hold fine mesh net in downstream direction
2) Use one foot to kick substrate towards net
3) Work upstream so uncaught organisms flow downstream, prevents more organisms being caught than present

Question 6

What are the steps for quadrat sampling?

Answer 6

1) Form measured grid
2) Select random coordinates using generator
3) Place quadrat at coordinates
4) Count number of individuals in a quadrat
5) repeat
6) Find mean per m2
7) Multiply by area of grid

Question 7

What are line transects used for?

Answer 7

To see distribution of different species change along a habitat

Question 8

What is a belt transect?

Answer 8

Quadrats are placed one after the other

Question 9

What is a line transect?

Answer 9

Anything touching tape is recorded

Question 10

What is an interrupted transect?

Answer 10

Quadrats placed at regular intervals

Question 11

What is succession?

Answer 11

changes in a community over time due to changes in abiotic conditions caused by species present

Question 12

How does secondary succession work?

Answer 12

-Occurs after existing vegetation is removed
-Soil is already fertile
-Seeds/spores easily dispersed by wind
-Rate of development is faster

Question 13

Describe a pioneer community

Answer 13

-Can’t compete for resources
-Can fix Nitrogen and enrich soil
-Can tolerate extreme conditions
-Not influence by animals
-Early arrivals

Question 14

Describe a climax community

Answer 14

-End point community
-Strongly influenced by other organisms
-Cant tolerate changes in soil water content
-Large seeds
-Good means of dispersal
-Specialised niche

Question 15

How do humans affect succession?

Answer 15

-Farming
-Controlled fires
-Extinguishing forest fires
-Deforestation
-Soil erosion

Question 16

What is photosynthetic efficiency?

Answer 16

How well a plant can trap light energyH

Question 17

How is photosynthetic efficiency calculated?

Answer 17

PE= Light trapped/ Light falling on leaf x100

Question 18

Why is energy lost in producers?

Answer 18

-Reflected off of leaf
-Wrong wavelength of light
-Transmits through and misses chloroplasts and chlorophyll

Question 19

How is energy lost between producers and primary consumers?

Answer 19

-Respiration
-Growth
-Reproduction
-Inedible parts of plant

Question 20

How is energy lost between primary and secondary consumers?

Answer 20

-Respiration
-Growth
-Reproduction
-Defecation
-Non predatory death

Question 20

What is NPP?

Answer 20

-Net primary production
-Energy after respiration to make into biomass

Question 21

What is GPP?

Answer 21

-Gross primary production
-Energy recieved

Question 21

What human activities affect the Carbon cycle?

Answer 21

-Deforestation
-Burning fossil fuels
-Increase in decomposition

Question 21

What are the effects of global warming?

Answer 21

-More extreme weather
-Melting ice caps
-Soil erosion
-Increased extinction rate

Question 21

How does agriculture affect the Carbon footprint and how can it be combatted?

Answer 21

-Machinery
-Chemical use
-Transport produce

-Produce less meat
-Alternative to rice paddies
-Reduce distance travelled

Question 22

What organisms are involved with ammonification?

Answer 22

Bacteria and fungi

Question 22

What organisms are involved with nitrification?

Answer 22

Ammonium compounds to Nitrites: Nitrosomas
Nitrates:Nitrobacter

Question 22

What organisms are involved with nitrogen fixing?

Answer 22

Rhizobium and azotobacter

Question 22

What organisms are involved with denitrification?

Answer 22

Pseudomonas

Question 22

How can human activity help the nitrogen cycle?

Answer 22

-fields of clover
-Chemical fertiliser
-Sewage disposal
-Draining fields
-Ploughing fields

Question 22

How is eutrophication minimised?

Answer 22

-10m fertiliser exclusion zone around lakes
-Dig drainage
-Reduce fertiliser use
-Don’t spread fertiliser when rain forecasted
-Only spread fertiliser when plant is growing