Revision for bio paper 1

[Tina Yuzuki]

Hi this thread is created to discuss all the biology paper 1 questions that you find difficult so we can discuss together and help each other. Hopefully we will be able to learn something and get a***

 

[Sheikh Nahiyan]

Great thing Tina Thanks for opening this separate thread :')

Which paper do you have for Bio practical? 33 or 34? If 34 then we can discuss it

 

[Tina Yuzuki]

Im taking p34 and I've posted some of my tips in this thread check it out https://www.xtremepapers.com/community/threads/anyone-taking-as-biology-p34.26958/

 

[Sheikh Nahiyan]

Im taking p34 and I've posted some of my tips in this thread check it out https://www.xtremepapers.com/community/threads/anyone-taking-as-biology-p34.26958/

I did check it out Not "that" of a help but still it was helpful

 

[KWIKIW]

Hi.I have a difficulty in qs 22 in may june 2009 paper.
I found it hard to choose between c and d.

 

[daredevil]

Hi.I have a difficulty in qs 22 in may june 2009 paper.
I found it hard to choose between c and d.

look C is the correct choice because in D suddenly alll traces of the previous nitrogen are gone totally but according to the semi-conservative theory thingy all part of the first DNA will be contributed to the daughter DNA too.... so even if it has a little trace of the N15 they will be passed on even if it is just the most minimal amount.... so the graph wil not touch the x axis i think bcz there will always b a tiniest of atom or molecule or a teeeny tiny fraction of the N15 left in there.

 

[h4rriet]

Hi.I have a difficulty in qs 22 in may june 2009 paper.
I found it hard to choose between c and d.

look C is the correct choice because in D suddenly alll traces of the previous nitrogen are gone totally but according to the semi-conservative theory thingy all part of the first DNA will be contributed to the daughter DNA too.... so even if it has a little trace of the N15 they will be passed on even if it is just the most minimal amount.... so the graph wil not touch the x axis i think bcz there will always b a tiniest of atom or molecule or a teeeny tiny fraction of the N15 left in there.

It's C because the % of DNA left after five generations is 1/32%. That's 3.125.
Or you can do measurements to check:

 

[KWIKIW]

Thanks .
Now,I understood how c comes.

 

[KWIKIW]

Do you know how to do qs 18 and 31 qs in 01/ oct/nov 2008 ?

 

[h4rriet]

Do you know how to do qs 18 and 31 qs in 01/ oct/nov 2008 ?

18. Substance X replaces chromosome telomeres which promote DNA replication. Normally, telomeres are not completely replaced during mitosis. Abnormally, substance X is added & it replaces telomeres. That means DNA replication is promoted. DNA replication will cause continual cell division. Substance X is not completely replaced; after each division, it becomes less and less and finally isn't there at all. That means DNA replication becomes less and less, and eventually stops.

 

[KWIKIW]

18. Substance X replaces chromosome telomeres which promote DNA replication. Normally, telomeres are not completely replaced during mitosis. Abnormally, substance X is added & it replaces telomeres. That means DNA replication is promoted. DNA replication will cause continual cell division. Substance X is not completely replaced; after each division, it becomes less and less and finally isn't there at all. That means DNA replication becomes less and less, and eventually stops.

Thanks.

 

[fjmskt]

An adult human has approximately 5dm3 of blood, which circulates about once a minute.
100 cm3 of atrial blood carries 19cm3 of oxygen. 100cm3 of venous blood carries 12.5 cm3 of oxygen.
what is the approximate volume in cm3 of oxygen taken up per minute in the lungs?