BIOLOGY - B6 - Monitoring The Environment

• Distribution definition 


  Where an organism is found
• Abundance definition 


  The number of organisms present
• Sampling is a means of collecting observations or measurements from a small area which is representative of a lager area.
• Sampling methods:

  Pooter - suck in the mouthpiece to draw insect into the holding chamber - it’s to catch small insects

  
  

  Sweep nets - they can be used to catch insects into the net - for flying insects or those living in long grass

  kick sampling - kick the riverbank and hold the net downstream - to capture the organisms in the water

  tree beating - hold out a cloth under a tree and shake it to dislodge invertebrate- for organisms in trees and bushes

  pitfull traps - used to capture crawling organisms suck as beetles, spiders and slugs
• Selective breeding definition, and examples?


  choosing the desire characteristics of parents and breeding them to have offspring with that characteristic

  e.g. domestication (wild species->farm animals)

  higher crop yields

  more milk in dairy

  variation in food colour
• Method of selective breading? ($couldbea6er$)

  1. decide which characteristics of the species is desirable
  2. select parents with high levels of desired characteristics
  3. breed these individuals
  4. select the best offspring and breed them together
  5. repeat this process for many generations of offspring, until all offspring have the desired characteristic.
• Why couldn't a farmer rely on the first gen of selective breading to give them the desired characteristic?

  cant rely on the desire alleles being expressed from 1 generation.
• Advantages to selective breeding?


  selects specific characteristics for offspring

  increases yields of crops
• Disadvantages of selective breeding?


  can lead to inbreeding

  reduces the gene pool

  can cause genetic diseases

  lots of alleles in a species
• Capture-recapture Technique

  1. Capture organisms from sample area, mark and release.
  2. At a later date, recapture organisms in the original sample area
  3. Record the number of marked and unmarked individuals

  (1st sample size X 2nd sample size) / number of recaptured marked individuals
• Quadrat 


  Can be uses to sample plants within the quadrat, counted and then recorded
• Random Plant Sampling 


  Individuals are selected by chance mark out a grid use a random number generator to select coordinates it must prevents bias.
• Non Random Sampling / Transect Sampling

  used to study how the distribution of organisms changes over a distance. e.g up a rocky shore. samples are taken at a fixed position along the line.
• How to do Non-Random (transect) sampling?

  1. use a quadrat and tape measure
  2. place quadrat at regular intervals along the tape measure
  3. count the abundance of individuals
  4. calculate the mean average of individuals and scale up the result
• light meters 


  measures light intensity (time of day affects light intensity)
• Identification keys 


  Identify living organisms by asking a series of questions about and organism's characteristics.
• Dichotomous Key


  correct answers tell you which question to go next, to identify species
• Which method of sampling focuses on the identification and abundance of plant species within a habitat?


  Random Sampling
• Which sampling method focuses on the abundance and distribution of plant species across across a habitat?

  Non-random / Transect Sampling
• 235 painted lady butterflies were marked and releases. The next day 80 painted lady butterflies were captures and it was found that 24 of them where tagged. Estimate the number of painted lady butterflies in this area .

  (235 X 80) / 24 = 784
• Which type of sampling requires a random number generator and why?

  Random sampling to prevent bias.
• Why would there be lower abundance and biodiversity under an oak tree?


  Because there would be less light for photosynthesis, resulting in less (variation of) plants.
• What is the difference between random and transect sampling?


  Transect is on a line and measures distribution of species.

  Random is 2 lots of tape measures and measures the abundance.
• Sampling technique PAG3

  
• Biodiversity


  The variety of living organisms in an area.
• Why is biodiversity important to maintain?


  To prevent loss of species, all species rely on each other
• What is Eutrophication?


  Fertilizers from crops runoff into water causing algae to bloom starving the water organisms of nutrients and oxygen.
• Human impacts of biodiversity

  • DESRUCTION - urbanisation, changes of land
  • AGRICULTURE - removing species to plant species
  • EXPLOITATION - overfishing, hunting, sport, over farming
  • POLLUTION - air, water and ground pollution changes where organisms can survive
  • EUTROPHICATION - staving water organisms of oxygen because of algae.
  • INTRODUCING INVADING SPECIES - alien species compete with natural
  • CLIMATE CHANGE - rising temp changes habitats too quick for species to adapt
• Conservation


  Protecting natural environment to ensure habitats are not lost.
• Method of conservations:

  1. Protect habitats for species to live in (nature reserves)
  2. Educating the public to make them aware of the problem
  3. Captive breeding programs in zoos to increase the population of endangered species
  4. Seed plants to store rare plants.
  5. Legal protection to stop poaching and trade
• IUNC - A published red list for endangered species and what efforts are being made for them.

  CITIES - To prevent the trade of these endangered species or animals
• Ecotourism 


  Aims to ensure tourism does not have a negative impact on the natural environment.
• What is genetic engineering?


  Inserting foreign genes from one organism to another.
• In which industries can genetic engineering be used?


  medical

  food

  research
• Why are bacteria often used for carrying the desired gene?


  They replicate quickly.
• Vectors 


  A DNA molecule used as a vehicle to deliver foreign DNA into another cell.
• Plasmid 


  Loop of DNA from bacteria.
• Genetic engineering human insulin in bacterial cells:

  
• How is genetic engineering for human insulin created?

  1. remove the plasmid
  2. Use a restriction enzyme to cut open the plasmid and human gene
  3. Use ligase to connect the insulin gene to the plasmid
  4. Insert the vector back into the bacteria
  5. Let the bacteria to multiply and produce insulin.
• Method of genetic engineering:

  1. Remove the required gene from a human cell (ISOLATE)
  2. Use RESTRICTION ENZYME to cut the gene for insulin for the DNA
  3. Use the same RESTRICTION ENZYME to cut the plasmid out of the bacterial cell
  4. Insert the gene for human insulin into the PLASMID
  5. Use an enzyme called LIGASE to join the ends of the human gene and the plasmid
  6. Put the plasmid back into the bacterial cell, known as a vector
  7. Leave the bacteria to divide and multiply by MITOSIS producing human insulin