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    (Original post by ramanan)
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    Thanks that really puts me at ease, I wish you very good luck
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    (Original post by Chinensis8)
    What do you guys think will come out?
    Panicking here!:eek:
    I'm so worried over biology I had a dream about totipotency. That could come up. Dream doesn't mean anything but has it come up in a while?
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    (Original post by Chinensis8)
    What do you guys think will come out?
    Panicking here!:eek:
    I feel like there could be a big fertilization question


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    (Original post by SyedaK)
    I'm so worried over biology I had a dream about totipotency. That could come up. Dream doesn't mean anything but has it come up in a while?
    Ok Totiptency, I had slight dreams about cell walls. I'm so nervous I feel like an anorexic about to purge

    (Original post by TheUndercoverPanda)
    I feel like there could be a big fertilization question


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    Ok fertilization. *sigh* Anyone know anything about the difference in starch and cellulose and microfibrils?
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    (Original post by Chinensis8)
    Ok Totiptency, I had slight dreams about cell walls. I'm so nervous I feel like an anorexic about to purge



    Ok fertilization. *sigh* Anyone know anything about the difference in starch and cellulose and microfibrils?
    1. both made up of glucose / eq ;
    2. both {have(1-4) glycosidic bonds / made by
    condensation reactions} / eq ;
    3. both have 1-4(glycosidic) bonds ;
    4. starch is α glucose, cellulose is β glucose ;
    5. starch composed of {more than one type of
    molecule / amylose and amylopectin ;
    6. correct reference to {branching / 1-6 bonds /
    helix} in starch / straight chain in cellulose ;
    7. all monomers same orientation in starch /
    every other one inverted in cellulose ;
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    (Original post by Chinensis8)
    Ok Totiptency, I had slight dreams about cell walls. I'm so nervous I feel like an anorexic about to purge



    Ok fertilization. *sigh* Anyone know anything about the difference in starch and cellulose and microfibrils?
    Starch is alpha glucose and cellulose is beta glucose, microfibirils are bundles of cellulose molecules found in the cell walls of plants held together by pectin
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    (Original post by ramanan)
    1. both made up of glucose / eq ;
    2. both {have(1-4) glycosidic bonds / made by
    condensation reactions} / eq ;
    3. both have 1-4(glycosidic) bonds ;
    4. starch is α glucose, cellulose is β glucose ;
    5. starch composed of {more than one type of
    molecule / amylose and amylopectin ;
    6. correct reference to {branching / 1-6 bonds /
    helix} in starch / straight chain in cellulose ;
    7. all monomers same orientation in starch /
    every other one inverted in cellulose ;

    (Original post by Whostolemycookie)
    Starch is alpha glucose and cellulose is beta glucose, microfibirils are bundles of cellulose molecules found in the cell walls of plants held together by pectin
    Alright! Thanks~
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    What are the meaning to these keywords:
    niche
    ecosystem
    species
    species richness
    genetic variation
    population
    habitat diversity
    community
    endemism
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    (Original post by Chinensis8)
    Ok Totiptency, I had slight dreams about cell walls. I'm so nervous I feel like an anorexic about to purge



    Ok fertilization. *sigh* Anyone know anything about the difference in starch and cellulose and microfibrils?
    Starch:
    • contains amylose and amylopectin joined by alpha glycosidic bonds.
    • Amylose = straight chained (due to 1,4 glycosidic bonds).
      • so it develops coiled structure (H bonds within chain forming helix) - more compact - more can fit in small space.

    • Amyloectin = branched (1,6 glycosdic bonds)
      • branches more easily hydrolysed, therefore quicker source of glucose to be used in respiration

    • Long polymer so insoluble
      • doesn't effect osmotic pressure of cell

    • Used for storage


    Cellulose:
    • made of beta glucose monomers joined by beta glycosidic bonds
    • Straight chained
    • H bonds between chains forming microfibrils
      • microfibrils contain between 50-80 adjacent glucose chains

    • Also insoluble
    • Used for structural support
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    (Original post by Whostolemycookie)
    What are the meaning to these keywords:
    niche
    ecosystem
    species
    species richness
    genetic variation
    population
    habitat diversity
    community
    endemism
    Here this could help.
    Attached Images
  1. File Type: pdf Biology Unit 2 Topic 4 Summary.pdf (335.8 KB, 106 views)
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    (Original post by Chinensis8)
    Ok Totiptency, I had slight dreams about cell walls. I'm so nervous I feel like an anorexic about to purge



    Ok fertilization. *sigh* Anyone know anything about the difference in starch and cellulose and microfibrils?
    Well all we can do is try!

    From what I learnt:
    Similarities:
    Starch and Cellulose are both made of glucose
    Both chains are linked together by 1,4 gylcosidic bonds

    Differences:
    Starch is a mixture of two polysaccharides (Amylose and Amylopectin)
    Between 50 and 80 cellulose chains are linked together by large number of hydrogen bonds to from strong threads called microfibrils
    Cellulose is unbranched long chain
    Starch is coiled and branched

    The cell wall contains cellulose micro-fibrils in a net like arrangement - the strength of microfibrils and their arrangement gives plants strength
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    im so nervous

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    (Original post by SyedaK)
    Well all we can do is try!

    From what I learnt:
    Similarities:
    Starch and Cellulose are both made of glucose
    Both chains are linked together by 1,4 gylcosidic bonds

    Differences:
    Starch is a mixture of two polysaccharides (Amylose and Amylopectin)
    Between 50 and 80 cellulose chains are linked together by large number of hydrogen bonds to from strong threads called microfibrils
    Cellulose is unbranched long chain
    Starch is coiled and branched

    The cell wall contains cellulose micro-fibrils in a net like arrangement - the strength of microfibrils and their arrangement gives plants strength

    (Original post by Matterhorn)
    Starch:
    • contains amylose and amylopectin joined by alpha glycosidic bonds.
    • Amylose = straight chained (due to 1,4 glycosidic bonds).
      • so it develops coiled structure (H bonds within chain forming helix) - more compact - more can fit in small space.

    • Amyloectin = branched (1,6 glycosdic bonds)
      • branches more easily hydrolysed, therefore quicker source of glucose to be used in respiration

    • Long polymer so insoluble
      • doesn't effect osmotic pressure of cell

    • Used for storage


    Cellulose:
    • made of beta glucose monomers joined by beta glycosidic bonds
    • Straight chained
    • H bonds between chains forming microfibrils
      • microfibrils contain between 50-80 adjacent glucose chains

    • Also insoluble
    • Used for structural support
    Thanks~ I kinda blanked out when I saw the q on a past paper
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    (Original post by Chinensis8)
    Here this could help.
    I can't see it because I don't have adobe reader, can you write it out for me
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    2 hrs and 50 minutes till the exam.

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    (Original post by Rubyturner94)
    im so nervous

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    I get hungry when I'm nervous so I'm eating. Maybe you should eat something
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    guys here's some use full tip I found thought i might share them

    when asked to explain a graph try write these
    1.state whether it show positive or negative coorelation
    2.Manupulate data
    3.state liner non liner

    also have a look at this qustion before u leave

    plant tissue cuture
    2010 jan 3c

    best of luk to all gona sign out, 3hrs more

    Lets hope for the best
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    (Original post by Whostolemycookie)
    What are the meaning to these keywords:
    niche
    ecosystem
    species
    species richness
    genetic variation
    population
    habitat diversity
    community
    endemism
    Niche - role of organism within a habitat
    Ecosystem - a biological community of interacting organisms and their physical environment.
    Species - a group of similar (similar behaviourally, physiologically and anatomically) organisms that can interbreed to produce fertile offspring.
    Species richness - number of species in a given habitat at a given time
    Genetic variation - number of alleles in a gene pool of a species
    Population -the number of organisms within a particular species.
    Habitat diversity - the number of different types of habitats in a given area
    Community - the various populations in an area.
    Endemisms- organisms that live in one particular are/habitat.

    Good luck today!
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    (Original post by Whostolemycookie)
    I can't see it because I don't have adobe reader, can you write it out for me
    Biodiversity the variety and variability among living organisms and the ecological complexes in which they occur
    Species a group of organisms with similar morphology, physiology and behaviour, which can interbreed to produce fertile offspring and which are reproductively isolated from other species
    Habitat place where an organism lives. Each habitat has a particular set of conditions which supports a distinctive combination of organisms
    Population a group of interbreeding individuals of the same species found in an are
    Community various populations in a community
    Niche the way an organisms exploits its environment. If two species live in the same habitat and have the same role within the habitat (same food, time of feeding, shelter) they occupy the same niche and will compete.
    Behavioural adaptions any actions by an organism which help them to survive and reproduce
    Physiological adaptions features of the internal workings of an organism which help them to survive and reproduce
    Anatomical features structures we can see when we observe or dissect an organism

    Co-adaption when two organisms depend on each other to survive
    Natural selection mechanism by which organisms change over time as they adapt to their changing environments
    Hacking out animal being taken out into forest and gradually given more freedom and less food to encourage animals to feed for themselves
    Reintroduction breeding animals in captivity that are returned to native habitat
    Species richness Number of species ina given area
    Genetic variation Number of allele in a gene pool of a species
    Endemisms An organism that is found only in one area

    I just copied and pasted it :0
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    Quick question - can anyone run through the steps that lead to differential gene expression?
 
 
 
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