Genetic information

• When analysing markets, a range of assumptions are made about the rationality of economic agents involved in the transactions
• The Wealth of Nations was written

  1776
• Rational


  (in classical economic theory) economic agents are able to consider the outcome of their choices and recognise the net benefits of each one
• Consumers act rationally by

  Maximising their utility
• Producers act rationally by

  Selling goods/services in a way that maximises their profits
• Workers act rationally by

  Balancing welfare at work with consideration of both pay and benefits
• Governments act rationally by

  Placing the interests of the people they serve first in order to maximise their welfare
• Rationality in classical economic theory is a flawed assumption as people usually don't act rationally
• Marginal utility

  The additional utility (satisfaction) gained from the consumption of an additional product
• If you add up marginal utility for each unit you get total utility
• Mistake: "The genome is all the genetic information within a cell."
• Mistake: "The genome is all the genes within a species or population."
• Mistake: "The proteome is all the proteins in a cell."
• Mistake: "tRNA carries / brings amino acids."
• Mistake: "In transcription, polymerase joins nucleotides."
• Mistake: "RNA polymerase forms hydrogen bonds / joins together complementary bases."
• 4.3 Genetic diversity can arise as a result of mutation or during meiosis
• Meiosis

  1. In interphase, DNA replicates → 2 copies of each chromosome (sister chromatids), joined by a centromere

  2. Meiosis I (first nuclear division) separates homologous chromosomes

  3. Meiosis II (second nuclear division) separates chromatids

  4. Outcome = 4 genetically varied daughter cells, normally haploid (if diploid parent cell)

  
• n

  Unpaired chromosomes
• The number of chromosomes is halved during meiosis
• Importance of meiosis

  
• Genetic diversity is the number of different alleles of genes in a population
• Alleles

  Variations of a particular gene (same locus) with different DNA base sequences, arise by mutation
• Population

  A group of interbreeding individuals of the same species
• Importance of genetic diversity
• Evolution

  Change in allele frequency (how common an allele is) over many generations in a population, occurring through the process of natural selection
• Principles of natural selection in the evolution of populations

  Mutation: Random gene mutations can result in new alleles of a gene

  2. Advantage: In certain environments, the new allele might benefit its possessor

  3. Reproductive success: Possessors are more likely to survive and have increased reproductive success

  4. Inheritance: Advantageous allele is inherited by members of the next generation (offspring)

  5. Allele frequency: Over many generations, the allele increases in frequency in the population
• Types of adaptations

  • Anatomical - structural / physical features that increase chance of survival

  Physiological - processes / chemical reactions that increase chance of survival

  Behavioural - ways in which an organism acts that increase chance of survival
• Aseptic techniques to investigate the effect of antimicrobial substances on microbial growth

  Prepare area using aseptic techniques (wash hands, sterilise equipment, flame, etc.)

  2. Transfer bacteria from broth to agar plate using aseptic techniques

  3. Spread bacteria evenly over agar plate

  4. Place discs soaked in different antimicrobials onto agar plate

  5. Lightly tape lid, invert and incubate

  6. Measure diameter of inhibition zones
• Importance of maintaining a pure culture of bacteria
• Reason for not sealing plate completely
• Purpose of control disc with water
• Reason for incubating upside down
• Reason for not using higher antimicrobial concentrations
• Reason for incubating at 25°C or less
• Presenting data on effect of antimicrobial substances

  Categorical data → bar chart (X axis type of antimicrobial, Y axis inhibition zone diameter), Continuous data → line graph (X axis antimicrobial concentration, Y axis inhibition zone diameter)
• Why hold lid with 2 pieces of tape instead of sealing it completely?

  Allows oxygen in preventing growth of anaerobic bacteria
• Why use a paper disc with water / no antimicrobial agent?

  • Act as a control
  • Ensuring antimicrobial prevented growth, not paper disc
• Why incubate upside down?

  Condensation drips onto lid rather than surface of agar
• What if inhibition zones are irregular?

  Repeat readings in different positions, calculate a mean