M6:T1 Diveristy of life

• how many species on earth

  • estimate of 2 million, mostly inverbrets
  • 2-6 million for microbes
  • 78-91% bacteria
  • <0.5% plants
• why can we not culture some microbes

  1. dormant, and cannot be cultured w/o the same conditions
  2. need help from other organisms to work
  3. are not viable in the environment
• list the molecular diversity

  1. genome
  2. prokay chromo
• define prokaryotic chromosome

  • single circular DNA
  • DNA is not membrane found but nucleotide region
  • -ve supercoiled is not associated with histone proteins
  • genome size is extremely heterogenous
  • carriers 1 full copy and serval partical copies to help with fast growth
• explore genomics


  sequencing: order of nucleotide bases

  genome annotation: converting raw seq data into a list of genes present in genome , helps predict what genes are
• what gives valuable info

  1. seq
  2. genome structure
  3. gene content
  4. order
  5. funotion
• what can genomes tell us

  1. heat stable enzymes to virulance factors
  2. studying: gene expression, detecting horz gene transfer, moinotring disease outbreaks, disovering crisprs, and understanding metabolism and growth
  3. ID new and unknown microbes
  4. help give understanding of the roles of organisms and info if there is a prophage present
• define plasmids

  • small circular and self-replicating extra chromo genetic element
  • permit bacteria to store add genetic info
  • rang size: 1kbp > 1mbp
• list examples of plasmids

  • antibiotic products
  • F plasmid <— conjugation
  • r plasmid <— antibiotics
• what are 3 transposable genetic elements

  1. insertion seq: short specific seq of DNA that can move to other sites on genome as discrete units
  2. transposons: movable elements conating genetic regions flanked by paired insertion seq<— production of structural proteins
  3. island: large movable elements flanked by insertion seq<— virulence genes
• how do new species arise

  1. random genetic mutation and natural selection
  2. fav mut: increase gene pool and diversity
  3. horz gene transfer
  4. gene loss
  5. variation in genome passed down generations
• explore new strains

  • serious implication on health
  • emerging and re-emerging due to antibiotic resistance and increase virulence
  • gene-transfer