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AQA BIOL2~3rd June 2013~AS Biology (Now Closed)

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Does anyone know if we get given the species diversity index all of the time in questions???

If you reply can you quote please:smile:)
Original post by annaelizabet


synodontis batensoda becasue its branched off closer to the Synodontis membranacea
What causes the S shape of the hameoglobn curve?
?God been gone an hour and this thread has gone so fast.
Original post by PoorLoser
Mochokus niloticus :biggrin:



HOW? i do not understand, wouldn't it be the one closer to it?
Reply 2924
Avatar for LiamDaly
LiamDaly
Original post by LiamDaly
What are the possible plant 6 mark questions??????

Please


Posted from TSR Mobilehh




This will come up Damm it what are the possible questions please?


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Original post by Simran Mars Foster
What causes the S shape of the hameoglobn curve?
?God been gone an hour and this thread has gone so fast.


The haemoglobin after it absorbs one oxygen, it easily absorbs the last 3 easily, this causes the S. :redface:

Correct me if I'm wrong :smile:

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Original post by Linked
can someone give me a six marker on meiosis please - with independent segregation and crossing over as well.

Please I am really struggling with this topic and I have a feeling that this is what they are going to ask tomorrow.

Also has anyone done the January 2013 paper - the asthma investigation question was really hard. But does anyone know how the graph should look - please.


Second the meiosis one.
Original post by Linked
can someone give me a six marker on meiosis please - with independent segregation and crossing over as well.

Please I am really struggling with this topic and I have a feeling that this is what they are going to ask tomorrow.

Also has anyone done the January 2013 paper - the asthma investigation question was really hard. But does anyone know how the graph should look - please.


Meiosis is similar to mitosis almost so basically in prophase the chromosomes will condense and shorten and the spindle fibres form. In metaphase, the chromosomes attach to the spindle and line up at the equator of the cell. Crossing over then occurs so the chromatids all twist around each other, causing bits to break off and alleles to be exchanged.

The independent segregation of chromosomes also occurs in metaphase so the homologous chromosomes line up alongside their partners and shuffle about and separate randomly which means each daughter cell gets a different set of chromosomes ensuring that they're not genetically identical. In anaphase, chromosomes are pulled to opposite poles of the cell unlike in mitosis where chromatids are pulled to opposite poles. Then finally, in telophase, the nuclear envelope reforms around each group of chromosomes and cytokinesis occurs so the cytoplasm divides forming two daughter cells that are different.
yes the eqation is given in all the questions ive seen
http://filestore.aqa.org.uk/subjects/AQA-BIOL2-QP-JAN12.PDF (q7aii)
Reply 2929
Avatar for LiamDaly
LiamDaly
Original post by Locutus73
Second the meiosis one.




Third the meiosis one and also DAMM PLANT QUESTIONS.


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Original post by anonymousecheese
synodontis batensoda becasue its branched off closer to the Synodontis membranacea



no it isn't :P it is mochokus nilo thingy, i don't know why!
Reply 2931
Avatar for JM17
JM17
3
Original post by Simran Mars Foster
What causes the S shape of the hameoglobn curve?
?God been gone an hour and this thread has gone so fast.


When haemoglobin combines with the first o2 molecule, its shape alters in a way that makes it easier for other molecules to join too. But as the haemoglobin starts to become saturated, it gets harder for more oxygen molecules to join. As a result the curve has a steep bit in the middle where it's really easy for oxygen molecules to join, and shallo bits at each end where it's harder. The curve is steep, a small change in pO2 causes a big change in the amount of oxygen carried by the haemoglobin.
Original post by LiamDaly
Third the meiosis one and also DAMM PLANT QUESTIONS.


Posted from TSR Mobilehh


OK everyone,
for meiosis im sure you will get the marks if you DRAW IT with labels and explanations (same way you couldve drawn the phagocytosis in unit 1:smile:)
...that is what ill be doing
http://filestore.aqa.org.uk/subjects/AQA-BIOL2-W-QP-JAN11.PDF

3bii
Reply 2934
Avatar for LiamDaly
LiamDaly
Original post by LiamDaly
Third the meiosis one and also DAMM PLANT QUESTIONS.


Posted from TSR Mobilehh


Possible plant questions?


Posted from TSR Mobilehh
Reply 2935
Avatar for JM17
JM17
3
Original post by Magenta96
Meiosis is similar to mitosis almost so basically in prophase the chromosomes will condense and shorten and the spindle fibres form. In metaphase, the chromosomes attach to the spindle and line up at the equator of the cell. Crossing over then occurs so the chromatids all twist around each other, causing bits to break off and alleles to be exchanged.

The independent segregation of chromosomes also occurs in metaphase so the homologous chromosomes line up alongside their partners and shuffle about and separate randomly which means each daughter cell gets a different set of chromosomes ensuring that they're not genetically identical. In anaphase, chromosomes are pulled to opposite poles of the cell unlike in mitosis where chromatids are pulled to opposite poles. Then finally, in telophase, the nuclear envelope reforms around each group of chromosomes and cytokinesis occurs so the cytoplasm divides forming two daughter cells that are different.



Are you reciting a textbook? :smile:
the mohkookus one?
thats all the way at the top!!:rolleyes:
okay tomorrow when you get this question you will chose the one closest to the one they are asking about.
okay:smile:
Original post by Manni
Lool may as well to liven up this depressing revision mood


Lool it doesn't liven up ur mood if u don't get a reply from her. Might as well wait until the exams are over and then this depressing mood will be gone
Original post by anonymousecheese
the mohkookus one?
thats all the way at the top!!:rolleyes:
okay tomorrow when you get this question you will chose the one closest to the one they are asking about.
okay:smile:



http://filestore.aqa.org.uk/subjects/AQA-BIOL2-W-QP-JAN11.PDF

question 3bii?
Reply 2939
Avatar for Linked
Linked
6
Original post by magenta96
meiosis is similar to mitosis almost so basically in prophase the chromosomes will condense and shorten and the spindle fibres form. In metaphase, the chromosomes attach to the spindle and line up at the equator of the cell. Crossing over then occurs so the chromatids all twist around each other, causing bits to break off and alleles to be exchanged.

The independent segregation of chromosomes also occurs in metaphase so the homologous chromosomes line up alongside their partners and shuffle about and separate randomly which means each daughter cell gets a different set of chromosomes ensuring that they're not genetically identical. In anaphase, chromosomes are pulled to opposite poles of the cell unlike in mitosis where chromatids are pulled to opposite poles. Then finally, in telophase, the nuclear envelope reforms around each group of chromosomes and cytokinesis occurs so the cytoplasm divides forming two daughter cells that are different.



and so all of this process happens again during meiosis 2 but instead of chromosomes it will be chromatids. I think i finally got it - thank you:smile:

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