B4a

Question 1

What is a population?

Answer 1

-all the organisms of one species in a habitat

Question 2

What is a community?

Answer 2

-populations of different species living together

Question 3

How can you estimate population sizes by scaling up small sample areas?

Answer 3

• you can study small areas within a quadrat and scale up your findings to make an area for larger areas
• 1.count all organisms in 1m2 quadrat
  2. multiply number of organisms by total area (in m2) of the habitat

Question 4

How can you estimate population sizes using capture-recapture?

Answer 4

1-capture a small sample of the population and mark the animals in a harmless way
2-release them
3-recapture another sample. count how many of this sample are marked
-using this equation: (number in first sample*number in second sample)/number in second sample marked

Question 5

What are some important points about methods to estimate population sizes?

Answer 5

• sample size affects accuracy of estimation–the bigger sample the more accurate your estimation is likely to be
• when using the recapture data you have to make assumptions:
• no changes in population have occurred due to death or migration
• sampling methods were identical
• the marking hasn’t affected the individuals’s chances of survival

Question 6

How are ecosystems self-supporting?

Answer 6

• they contain almost everything they need to maintain themselves.
• water, nutrients and essentials like carbon get recycled within the ecosystem

Question 7

How can you investigate distribution of organisms?

Answer 7

• use lines called transects
• it is difficult to count the individual organisms in a quadrat
• instead estimate the percentage area of the quadrat covered by a particular organism
• e.g.by counting the number of little squares covered by the organisms
• you can plot results in a kite diagram

Question 8

What are abiotic condition?

Answer 8

-non-living conditions, e.g. temperature, salinity (saltiness) and soil quality

Question 9

What is an ecosystem?

Answer 9

-all the organisms living in a particular area, as well as the abiotic conditions

Question 10

What is a habitat?

Answer 10

-a place where an organism lives

Question 11

What is distribution?

Answer 11

-where organisms are found within a particular area

Question 12

How do you do a transect?

Answer 12

1-mark a line with a tape measure
2-place quadrats next to each other all the way along the line
3-count and record the organisms you find living there