Test Exam I.2

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  1. Majority of cyanobacteria are __. Some can be __; others may exhibit __.

    How can they exhibit this?
    • filamentous
    • unbranched
    • true branching

    How? Cells start dividing on a different plane (ex: they usually divide horizontally and then divide vertically)
  2. They also exhibit __. How can that be explained?
    • false branching
    • a break in the filament, causing separation (one continues to divide; another doesnt; this forms a branch)

    If both pieces continue to divide: a pair of false branches
  3. All in all, branches are mainly formed due to __.

    Sometimes, the filaments are __. In a few, there may be a __ around a __. 

    What may this do?
    a change in direction

    • single
    • gel matrix around a group of filaments

    may help survival and moisture to be retained= resistant to drying
  4. What are the characteristics needed to be considered multicellular?
    • differentiated cells (specialized)
    • specificity
  5. Cyanobacteria have __. The only "body type" with this is __. 

    What are the two cells?
    speciailzed cells


    1) heterocyst: occur in trichomes of some species; bigger than )and develop from) vegetative cells; round, thicker wall; not as granular; lighter in color

    2) akinetes
  6. Heterocysts
    1) function in __. 
    2) contain __ where there is a __ (beetween __) called __.

    3) How many __ there are varies.
    4) What does it do?
    • 1) nitrogen fixation
    • 2) polar nodules/ cytoplasmic connection/ heterocyst and neighboring vegetative cell/ microplasmodesmata
    • 3) polar nodules
    • 4) connects cells
  7. Nitrogen fixation
    1) occurs mainly in __. 
    2) Reaction? 
    3) What does this reaction do? 
    4) It takes __ to break the strong __ between __ of __.

    N2 + 12 ATP--> 2 NH3 + 12 ADP + 12 Pi

    make N available for the whole organism

    alot of energy (12 ATP)/ triple bond/ two nitrogen molecules/ N2 gas
  8. __ catalyzes nitrogen fixation. Very sensitive to __. A majority of cyanobacteria can't __. 

    What happens if the oxygen producing level is lower? 

    In heterocysts, you don't find __.

    Nitrogenase is inactivated when __.
    • nitrogenase
    • oxygen
    • fix nitrogen

    less pigments--> higher in color

    an oxygen-binding pigment

    oxygen is present
  9. Heterocysts and False Branching

    1) The cxn between __ and __ is a __. 
    2) This is where __.
    3) What does this explain?
    • 1) heterocysts/ vegetative cells/ point of weakness
    • 2) some branches form (between heterocysts and vegetative cells)
    • 3) why only one part of a branch forms
    • - if there are double branches, there may not have been a heterocyst at all
  10. A few __ can fix nitrogen.
    non-heterocyst cyanobacteria
  11. Akinetes
    1) size? 
    2) location
    3) appearance
    4) resistance
    • 1) enormous 
    • 2) sometimes next to a heterocyst
    • 3) very granular/ stacked with storage food (major function)
    • 4) resistant to adverse survival mechanisms; they can survive adverse conditions
  12. Akinetes cont.

    __ can develop from vegetative cells.

    Not a __; more of a __.

    Longest __ is __ years.

    reproductive structure; survival structure


    87 years (average: 70-80 years)
  13. No __ in cyanobacteria.

    Some filamentous forms demonstrate a __.
    - It may be due to __. 

    Not considered a __. 
    - how do they move? 

    One species of cyanobacteria (__) is capable of __.
    flagella/ cilia

    sliding/ gliding/ swaying/ or twisting motion

    extrusions of mucilage from pores

    form of motility

    move at the whim of currents


  14. Reproduction
    - no __, but instead __, leading to __, which are __.

    - no __ or __. 

    - each cy. has __.
    true sex. reproduction/ asex/ production of clones/ genetically identical

    mitosis or binary fission

    one molecule of DNA
  15. Explain duplication?
    attached to membrane--> cell increases in length--> formation of cell wall and membrane--> two new cells

    in colonies, they either do it together or separately
  16. Reproduction by formation of __. 

    • exospores
    • process of binary fission but the cells aren't identical in size
  17. Reproduction through __.
    • fragmentation
    • filaments grow--> buffeted around--> break off--> new organism
  18. Hormogonia
    - __
    - __

    Two basic forms of reproduction are __
    What are cy.
    • special fragmentation
    • - not very common

    binary fission and fragmentation

    cy. are the simplest organisms
  19. Location
    varies, but vast majority livein freshwater lakes (majority), rivers, streams

    • 20% marine
    • a few on moist soil, bare soil, or rock (usually next to a stream)
  20. Explain their attachment.
    Free floating or attached to other things (epiphytes)
  21. What does epiphyte refer to?
    means upon a plant, but refers to attachment to rocks and other things as well
  22. If floating, they are important as __.

    Cy are an important __ and are right at the __.

    They occur at a wider range of habitats and __.

    source of food/ baseof the food chain

    tolerate alot more than euk might not
  23. Example of extreme conditions.
    thermophilic (extreme heat) (true cant tolerate this)

    • really cold (but so can true algae)
    • high salilinty and really acidic and basic conditions
  24. Symbiotic cyanobacteria
    1) __.
    2) very often, they are found __.
    2a) When this occurs, they __.
    both organisms benefit

    inside the cell of an organism

    in here, they lack a cell wall- act as chloroplasts, giving rise to endosymbiosis idea
  25. Sym. cy. can grow with __ and have a __. 

    Aquatic ferns have __ containing cy. that __.
    • fungal cells (lichens)
    • unique structure
    • leaf cavities
    • fix nitrogen (cy benefit by receiving mroe light)
  26. __ is a cy. that contains __. 
    -Can be grouped with __ of __. 

    How do terrestrial plants benefit?

    • gametophytes
    • hornwort

    through the N fixation
  27. A majority of cyanobacteria have neither __ nor __.
    • heterocysts
    • akinetes
Card Set:
Test Exam I.2
2014-01-25 17:49:57
Plant Kingdom
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