PRE 2016

• (IMAGE) SUGGEST APPROPRIATE UNITS FOR GROSS PRODUCTIVITY

  unit of energy / mass , per area, per year

  
• (IMAGE) EXPLAIN THE DECREASE IN GROSS PRODUCTIVITY AS THE WOODLAND MATURES

  1. less light - more competition for light
  2. reduced photosynthesis

  
• (IMAGE) USE YOUR KNOWLEDGE OF SUCCESSION TO EXPLAIN THE INCREASE IN BIOMASS DURING THE FIRST 20 YEARS

  1. pioneer species
  2. change in abiotic conditions making it less hostile
  3. so increase in diversity if species

  
• (IMAGE) USE THE INFORMATION IN THE GRAPH AND YOUR KNOWLEDGE OF NET PRODUCTIVITY TO EXPLAIN WHY BIOMASS SHOWS LITTLE INCREASE AFTER 100 YEARS.

  1. net productivity = gross productivity - respiratory loss
  2. Decrease in gross productivity / photosynthesis / increase in respiration

  
• SUGGEST ONE REASON FOR CONSERVING WOODLANDS

  1. protecting habitats or niches
  2. protecting endangered species - increases biodiversity
  3. reduces global warming
  4. source of medicines
  5. reduces erosion or eutrophication
• ON ISLANDS IN THE CARIBBEAN, THERE ARE ALMOST 150 SPECIES OF LIZARDS BELONGING TO THE GENUS ANOLIS. SCIENTISTS BELIEVE THAT THESE SPECIES EVOLVED FROM TWO SPECIES FOUND ON MAINLAND USA. EXPLAIN HOW THE CARIBBEAN SPECIES COULD HAVE EVOLVED.

  1. Geographical isolation
  2. no interbreeding / separate gene pools
  3. variation due to mutation
  4. different selection pressures / abiotic or biotic conditions
  5. selected Organisms survive and reproduce
  6. increase in allele frequency
• ANOLIS SAGREI IS A SPECIES OF LIZARD THAT IS FOUND ON SOME OF THE SMALLEST CARIBBEAN ISLANDS. DESCRIBE HOW YOU COULD USE THE MARK-RELEASE-RECAPTURE METHOD TO ESTIMATE THE NUMBER OF ANOLIS SAGREI ON ONE OF THESE ISLANDS

  1. Capture sample, mark and release
  2. mark the lizard in a way that doesn’t hurt it or increase predation
  3. leave time for lizards to distribute then collect second sample
  4. population = number in first sample * number in second sample divided by number of marked lizards in second sample
• (IMAGE)

  1. in carbon dioxide linked with respiration at night
  2. No photosynthesis in dark, only in light
  3. in light more carbon dioxide used than produced , rate of photosynthesis greater than respiration
  4. decrease in carbon dioxide concentration with height
  5. at ground level, less photosynthesis and more respiration - more microorganisms produce carbon dioxide

  
• (IMAGE) CAN YOU CONCLUDE THAT THE INSECT PEST RESISTANT TO Bt TOXIN FOUND IN THE YEARS 2002 TO 2005 WAS THE SAME INSECT SPECIES? EXPLAIN.

  No - graph only shows number of species, not the name of the species

  
• (IMAGE) ONE FARMER STATED THAT THE INCREASE IN THE USE OF Bt CROP PLANTS HAD CAUSED A MUTATION IN ONE OF THE INSECT SPECIES AND THAT THIS MUTATION HAD SPREAD TO OTHER SPECIES OF INSECT. WAS HE CORRECT? EXPLAIN.

  NO

  1. mutations are spontaneous
  2. only the rate of mutation is affected by environment
  3. different species don’t interbreed and don’t produce fertile offspring
  4. so mutation can’t be passed down from one species to another

  
• (IMAGE) THERE WAS A TIME LAG BETWEEN THE INTRODUCING OF BT CROPS AND THE APPEARANCE OF THE FIRST INSECT SPECIES THAT WAS RESISTANT TO THE BT TOXIN.

  EXPLAIN WHY THERE WAS A TIME LAG.

  1. Initially few insects with favourable allele / mutation
  2. individuals with favourable mutation / allele will have more offspring
  3. takes many generations for favourable mutation / allele to become the most common allele of this gene

  
• (IMAGE) PROPORTIONAL SAMPLING CAN BE USED TO ESTIMATE THE POPULATION SIZE OF A SPECIES THAT IS UNIFORMLY DISTRIBUTED.

  WHAT IS A SPECIES?

  organisms that interbreed and produce fertile offspring

  
• (IMAGE) WHAT IS MEANT BY UNIFORMLY DISTRIBUTED?

  same number of organisms in each region equally spread

  
• (IMAGE) USE THE LTTERS A, R AND S TO WRITE AN EQUATION SHOWING HOW PROPORTIONAL SAMPLING IS USED TO ESTIMATE THE TOTAL SUZE OF A POPULATION, P. SHOW WORKING.

  ANSWER: P = AS/R

  
• (IMAGE) POPULATION SIZE CAN BE ESTIMATED USING PROPORTIONAL SAMPLING OR MARK-RELEASE-RECAPTURE.

  HOW DO THE ASSUMPTIONS MADE IN PROPORTIONAL SAMPLING DIFFER FROM THOSE MADE IN MARK-RELEASE-RECAPTURE?

  IN MARK RELEASE RECAPTURE TECHNIQUE

  1. no assumption that organisms are uniformly distributed
  2. size of total area not required

  
• (IMAGE) GIVE ON ASSUMPTION ABOUT THE ANIMALS CAUGHT THAT IS MADE IN BOTH METHODS

  animals are from the same population