Unit 2 Biology synoptic essay

Created by: Elisha Bell
Created on: 22-04-14 13:44

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Gas exchange
- Surface area to volume ratio
  - Relates to heat loss
- Mass flow
  - Like a river containing solute
  - Faster than diffusion
  - Ventillation
- Sponges have thin walls and flagella inside to move water
- Tapeworms have flattened bodies
- Insects
  - Exoskeleton prevents drying out
  - Spiracles
    - Trachea
      - Tracheoles
        Oxygen diffuses directly into muscle cells
        
        At rest water stays here
        During muscle contraction lactic acid is produced which causes water (with oxygen) to diffuse into muscle cells)
      - Rings of chitin
        Polysaccharide
        Starch
        Plants
        
        Amylose
        Coiled
        
        Amylopectin
        Highly branched
        
        Broken down by Amylase
        
        Glycogen
        Animals
        
        Similar to Amylopectin
        
        Broken down quickly by glycogen phosphorylase
        
        Doesn't change water potential
        
        Fungal cell wall
    - Rings of chitin
      - Polysaccharide
        Starch
        Plants
        
        Amylose
        Coiled
        
        Amylopectin
        Highly branched
        
        Broken down by Amylase
        
        Glycogen
        Animals
        
        Similar to Amylopectin
        
        Broken down quickly by glycogen phosphorylase
        
        Doesn't change water potential
      - Fungal cell wall
  - Larger insects contract muscles to ventilate air
  - Preventing water loss
    - Spiracles close
    - Hairs around spiracles
- Fish
  - Very little oxygen in water
  - Gills
    - Fillaments
      - Lamellae
        Large surface area and short diffusion distance
  - Water enters the buccal cavity in a one way system as water is too dense to be ventiallated like in mammals
    - Leaves via the opercular valve
  - Countercurrent flow
- Humans
  - pulmonary
  - systemic
  - Blood vessels
    - Arteries
      - Thick elastic walls
        Can withstand high pressure
    - Arterioles
      - Thinner
        Smooth muscle
        Reduces blood flow between arteries and capillaries
    - Capillaries
      - Single cell walls
        Good for diffusion
    - Veins
      - Small veins called venules
      - Semi lunar valves to prevent backflow
        Returns blood to the heart-low pressure
        Large lumen
  - Pressure decreases from arteries to veins
  - Tissue fluid
    - Forced into tissue fluid by hydrostatic pressure
    - Re-enters capillary by diffusion
    - Excess drains into lymph vessels
      - Empties back into superior vena cava
      - White blood cells formed at lymph nodes
      - Lymph also contains fats
    - Oededma is swelling caused by excess tissue fluid due to lack of protein
- Oxygen
  - Transported by heamoglobin
    - 4 protein chains with 4 heam iron groups
      - One oxygen attached to each
    - Respiration produces CO2 which forms carbonic acid in red blood cells and lowers pH
      - Causes O2 to unload
    - Lugworms have a high affinity for oxygen as their burrows are covered by water
    - Mice have a high respiration rate so a low affinity for oxygen so loads is loaded
Hairs around spiracles
Plant organelles
- Chloroplasts
  - Thylakoid disks
    - Grana
  - Stroma
  - Chlorophyll
    - Mg ions are surrounded by porhyrin to make chlorophyll
      - Ions
        Untitled
        
        Untitled
  - Ribosomes
  - DNA
  - Starch grains
- Vacuoles
  - Filled with sap
  - Keeps cells rigid
- Cell wall
  - Cellulose
    - B-Glucose
      - Alternate molecules are inverted
    - Rigid straight chains
    - H bonds between microfibrils
    - Broken down by cellulase in bacteria
      - Herbivores have mutalistic bacteria
- Plants
  - Waterproof cuticle to prevent water loss
  - Gas exchange
    - Surface area to volume ratio
      - Relates to heat loss
    - Mass flow
      - Like a river containing solute
      - Faster than diffusion
      - Ventillation
    - Sponges have thin walls and flagella inside to move water
    - Tapeworms have flattened bodies
    - Insects
      - Exoskeleton prevents drying out
      - Spiracles
        Trachea
        Tracheoles
        Oxygen diffuses directly into muscle cells
        
        At rest water stays here
        During muscle contraction lactic acid is produced which causes water (with oxygen) to diffuse into muscle cells)
      - Larger insects contract muscles to ventilate air
      - Preventing water loss
        Spiracles close
    - Fish
      - Very little oxygen in water
      - Gills
        Fillaments
        Lamellae
        Large surface area and short diffusion distance
      - Water enters the buccal cavity in a one way system as water is too dense to be ventiallated like in mammals
        Leaves via the opercular valve
      - Countercurrent flow
    - Humans
      - pulmonary
      - systemic
      - Blood vessels
        Arteries
        Thick elastic walls
        Can withstand high pressure
        
        Arterioles
        Thinner
        Smooth muscle
        Reduces blood flow between arteries and capillaries
        
        Capillaries
        Single cell walls
        Good for diffusion
        
        Veins
        Small veins called venules
        
        Semi lunar valves to prevent backflow
        Returns blood to the heart-low pressure
        Large lumen
      - Pressure decreases from arteries to veins
      - Tissue fluid
        Forced into tissue fluid by hydrostatic pressure
        
        Re-enters capillary by diffusion
        
        Excess drains into lymph vessels
        Empties back into superior vena cava
        
        White blood cells formed at lymph nodes
        
        Lymph also contains fats
        
        Oededma is swelling caused by excess tissue fluid due to lack of protein
    - Oxygen
      - Transported by heamoglobin
        4 protein chains with 4 heam iron groups
        One oxygen attached to each
        
        Respiration produces CO2 which forms carbonic acid in red blood cells and lowers pH
        Causes O2 to unload
        
        Lugworms have a high affinity for oxygen as their burrows are covered by water
        
        Mice have a high respiration rate so a low affinity for oxygen so loads is loaded
  - Sub-stomatal air space is moist
  - Guard cells can close stomata
  - Spongy mesophyll cells have large air spaces
  - Xerophytes
    - Thick waxy cuticle
    - Small leaf surface area
    - Stomatal hairs
Loss of genetic diversity
- Genetic bottleneck
  - Population reduced dramatically
    - Small range of alleles
- Founder effect
  - Small colony
    - Small range of alleles
- Agriculture
  - monoculture
  - Selective breeding
  - Cutting down rainforests leads to desertification
DNA
- Nucleotides
  - Sugar
  - Phosphate
  - Base
    - Complimentary bases joined by H bonds
  - Phosphodiester bonds
    - Polynucleotides
    - Stable
      - Complimentary bases joined by H bonds
- Two antiparallel strands
- Double helix
- Long so contains lots of information
- DNA replication
  - Semi conservative
    - DNA helicase unzips
      - DNA poiymerase joins nucleotides
        Enzymes
      - Enzymes
  - Mitosis
    - Interphase
      - Not replicating
      - DNA replicated
    - Prophase
      - Chromosomes condensed and nucleolus disappears
    - Metaphase
      - Chromosomes line up on theequator of cell
      - Spindle fibres connect to centriolers
        Taxol is an anticancer drug that prevents breakdown of spindle fibres
    - Anaphase
      - Chromatids split
      - Pulled by motor proteins
    - Telophase
      - Two new cells formed after cytokinesis
  - Meiosis
    - One diploiud cell forms four haploid cells
    - Firstly homologous chromosomes are seperated then the individual chromatids split in the second divisikion
    - Variation
      - Independent assortment
        A mixture of different maternal and paternal chromosomes after the 1st division
      - Crossing over
        Occurs in the 1st division when bivalents of maternal and paternal chromosomes are formed andf genes are swapped
        
        Occurs at chiasmata
      - Random fertilisation
- DNA
- Exons and introns
- Mutations
  - Antibiotic resistance
    - Antibitoics
      - Must be selectively toxic
        Affects 70s ribosomes
        Prevents cell divisoion
        Mitosis
        Interphase
        Not replicating
        
        DNA replicated
        
        Prophase
        Chromosomes condensed and nucleolus disappears
        
        Metaphase
        Chromosomes line up on theequator of cell
        
        Spindle fibres connect to centriolers
        Taxol is an anticancer drug that prevents breakdown of spindle fibres
        
        Anaphase
        Chromatids split
        
        Pulled by motor proteins
        
        Telophase
        Two new cells formed after cytokinesis
    - Penicillinase enzyme caused by a mutation
    - Raqndom and not caused by the prescence of the antibiotic
    - Vertical gene transmission
      - Binary fission
      - Bacteria with resistance thrive if antibiotics are prewsent asd competing bactyeria are killed
        Natural selection
    - Horizontal gene transmission
      - genes passed by conjugation
      - Plasmids passed through a pilus
      - Causes multiple resistance
    - Mycobacterium tuberculosis (TB) is resistanrt to streptomysin
- Wrapped yp with histones to form chromatin
  - Coils to form chromosomes during replication
    - Two chromatids joined by a centromere
Classification
- A species can breed to produce fertile offspring and share a common ancestor
  - Courtship behaviour
    - Recognises members of the same species
    - Attracts a mate that is capable of breeding
    - Forms a pair bond to raise opffspring
- Kingdom, Phylum, Class, Order, Family, Genus, Species
- DNA sequencing can be used to compare organisms
- DNA hybridisation
  - Dna strand of two organisms is combined
  - Similar organisms will have lots off H bind between bases so it will take lots of heat to break the strands apart
- Proteins can be copared by injecting a rabbit with the protein, so it produces antibodies. These antibodies are combined with thge protein from different species and a varying amount of porecipitate is formed through Agglutination
Mg ions are surrounded by porhyrin to make chlorophyll
- Ions
  - Untitled
  - Untitled

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Unit 2 Biology synoptic essay

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