Edexcel 6BIO2 ~ 3rd June 2013 ~ AS Biology

i put an X in the far left hand box, but the mark scheme says it should be in the far right? Can anyone explain why? :/


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what kind of things would we need to know about plant fibres sustainability?

Because the bacteria would be in the far left as it's the most distant relative out of the three domains. The Eukaryotes are in the far right because they are more closely related to the Archaea (in the middle). This can be seen with the junctions on the diagram, which represent a common ancestor. Hope this helped!

Thank you, i still don't understand why bacteria is the most distantly related? Surely bacteria and archaea are most closely related ... This table was earlier on in the question and Q is eukaryotic, and it has the least things in common with the other two, so shouldn't it be the most distantly related?


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uses of mitosis:

- growth of multicellular organisms
- repair damaged tissue
edit: Asexual reproduction...lol hope i don't forget like that in the exam

cell cycle:

Interphase: Cell doubles dna content, increase in atp and organelles replicated.

Mitosis: 4 stages p.m.a.t.

-prophase: 1)chromosomes shorten and thicken 2) centrioles move to opposite ends and forms spindle 3) nuclear envelope breaks down.

-metaphase: 1)chromosomes line up in the middle 3)there centromere attach to the spindle

-anaphase: 1)spindle contracts seperating each sister chromatid to opposite ends pulling the centromere first 2) spindle breaks down

-telophase: 1)chromosomes unravel 2)nuclear envelope forms around both sets of chromosomes 3) nucleolus forms 4) cytoplasm divides forming two cells genetically identical.

Thank you, i still don't understand why bacteria is the most distantly related? Surely bacteria and archaea are most closely related ... This table was earlier on in the question and Q is eukaryotic, and it has the least things in common with the other two, so shouldn't it be the most distantly related?


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Q and R are most distantly related..

P and Q have 1 thing in common
P and R have 3 things in common
Q and R have nothing in common

Q and R are most distantly related..

P and Q have 1 thing in common
P and R have 3 things in common
Q and R have nothing in common

This is true, but then because P and R have 3 things in common, why aren't they the ones closer together, with R being at the far right and Q being the far left because they have nothing in common?

Eh nonetheless, all the diagrams show Archaea and Eukarya closer together than with Bacteria, so we just have to remember that :P

Yes i understand that Q and R are most distantly related. I don't understand how P and Q (archaea and eukaryotes) are most closely related, i would have thought P and R (archaea and bacteria) would be: as you said they have 3 things in common... But according to the answer to the tree question eukaryotes are most closely related to archaea?


Posted from TSR Mobile

Also, if you remember Woese's diagram, Archaea and Eukaryotes are more closely related than bacteria. Again, if you remember the diagram, the junctions show the common ancestor. Bacteria only has one common ancestor with the other two, whereas archaea and Eukaryotes share two common ancestors.

anyone please teeelll me...do we have to study meiosis steps ....like sperogenesis???????????

yes please!

This is true, but then because P and R have 3 things in common, why aren't they the ones closer together, with R being at the far right and Q being the far left because they have nothing in common?

Eh nonetheless, all the diagrams show Archaea and Eukarya closer together than with Bacteria, so we just have to remember that :P