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Biology Exam Revision - Coggle Diagram

- - - - Casts
      - Moulds
  - - - lack of decomposers
      - lack of oxygen
      - low temperatures
      - low-no humidity
      - mildly acidic
  - - - radioisotopes
      - tree rings
    - - fluorine
      - stratigraphy
- - - - Homologous structures between species are suggestive of a common ancestor
        
        Whale fin structure similar to human hand
    - - Serves as a timeline of Earth's development
      - displays an increase in the complexity and number of organisms of Earth as time went on
      - Can show ho changes in organisms are linked to changes in environment
    - - Different species at the embryotic level can possess certain features/structures in common. Which is suggestive of a common ancestor
      - e.g. pharyngeal gills in dogs and turtles
    - - Isolated species are typically more unique
      - Species already evolved before the splitting of Pangea are typically worldwide
      - animals in similar areas can develop similar adaptations to suite their environment
    - - If species have many genes in common, is suggestive of common ancestry
- - - - earliest of these organisms is cyanobacteria
        
        We know this through the rock like structures known as stromatolites that they leave behind
  - - - Earliest being a primitive fish found in Chengjiang, China (525M)
  - - - soon after, insects and vertebrates followed
  - - - Mammals first emerge (190MYA)
- - - - Phosphate Group
      - deoxyribose sugars
      - nitrogenous base
    - - long fragments of DNA molecule wrapped around a protein
      - the Protein is BIGGER than the dna
    - - a-t c-g
  - - - Helicase (separates DNA (splits down middle))
      - DNA polymerase (reconstructs DNA (places them in order))
      - ligase (sets the dna sequence built my dna polymerase )
      - primase (initialiser/tells DNA polymerase where to build)
    - - IPMAT (phases)
        
        Interphase
        
        chromosomes replicate to have two chromatids
        
        prophase
        
        Replicated chromosomes become visible and form homologous pairs
        
        metaphase
        
        homologous pairs line up at the equator attached to spindle like fibres
        
        anaphase
        
        chromatids separate and move to the poles of the cell
        
        telophase
        
        two nuclei form, each with the same number of chromosomes as the parent cell
        
        cytokinesis
        
        cell membranes from making two daughter cells each with a nucleus
      - somatic, creates 2 identical daughter cells (diploid number)
      - involved in growth and repair in multicell organisms
      - asexual reproduction
    - - produces gametes (haploid number), 4 different daughter cells
      - sexual reproduction/gamete production
  - - - Out of africa theory
        
        AS mitochondrial dna mutates at a fixed rate, we can use this information to find where the earliest humans originated based on how many mutations they have
        
        originated in east africa 100-200 thousand years ago
        
        60000 they leave
        
        15000 they colonise the Earth
- - - - isolation
      - variation
      - selection
  - - - Caused by selective agents found in nature that cause certain individuals to have a higher chance of producing offspring and passing their traits on.
    - - Interbreeding
        
        breeding 2 related individuals (typically not from outside the same genus) in the hope that they pass of their desirable traits to offspring
        
        done mostly in plants
      - Cross breeding
        
        breeding 2 individuals with desirable traits in the hope that they pass those traits to their offspring