Biology; Chemistry; Physics: Post your doubts here!

[Saad Mughal]

well look a maths student is better in our subject
anyway thnx

*computer student. We both take maths.

 

[asma tareen]

*computer student. We both take maths.

lol whateva

 

[Saad Mughal]

 

[Hskk]

Well because when we have flu or cold (viral infections), we don't take antibiotics because they are not effective (I know this).
A can't be the answer (what I think) because bacteria don't become immune to the antibiotics. Our body becomes immune to bacteria because of antibiotics (I know this is a weird explanation )

We don't take antibiotics in a viral infection so it's not a problem caused by using antibiotics.
Also, the bacteria does become resistant/immune to the antibiotic.

 

[Saad Mughal]

We don't take antibiotics in a viral infection so it's not a problem caused by using antibiotics.
Also, the bacteria does become resistant/immune to the antibiotic.

Ok. I know very little about Biology but,
Do bacteria become 100% immune to antibiotics? I think not because we use the same antibiotics over and over again but the antibiotic does affect the bacteria and help us feel better.
They're asking for problems of antibiotics, so, if they don't work on viral infections we have to create medicine and/or find ways to cure these infections that cannot be cured by antibiotics, this is a problem with antibiotics.

 

[AhsanAfzal]

C is correct. Antibiotics can select resistant bacteria from a population with a diverse gene
pool, but cannot cause bacteria to become immune. Viruses are not affected by antibiotics.

 

[HarithAslam]

Chemistry question,
so supposing a conical flask/burette has recently been used for titration and is washed out with acid/alkali, what steps are carried out before the flask/burette can be reused?

 

[Hskk]

Ok. I know very little about Biology but,
Do bacteria become 100% immune to antibiotics? I think not because we use the same antibiotics over and over again but the antibiotic does affect the bacteria and help us feel better.
They're asking for problems of antibiotics, so, if they don't work on viral infections we have to create medicine and/or find ways to cure these infections that cannot be cured by antibiotics, this is a problem with antibiotics.

C is correct. Antibiotics can select resistant bacteria from a population with a diverse gene
pool, but cannot cause bacteria to become immune. Viruses are not affected by antibiotics.

Constant use of the same antibiotics for a certain bacteria can cause it to become resistant to the effect of the antibiotic. The bacteria develops mutations over time and after many generations the best bacteria i.e. the one resistant to the medicine is naturally selected- thus evolution(I'm not atheist whatsoever, this is in the syllabus ). We can't see this change because it occurs after years of use. Also, the q says 'the problem of using antibiotics,' in the case of viruses we're not using antibiotics in the first place.

 

[Hskk]

Maybe they don't consider immunity synonymous to resistance?

 

[asma tareen]

Constant use of the same antibiotics for a certain bacteria can cause it to become resistant to the effect of the antibiotic. The bacteria develops mutations over time and after many generations the best bacteria i.e. the one resistant to the medicine is naturally selected- thus evolution(I'm not atheist whatsoever, this is in the syllabus ). We can't see this change because it occurs after years of use. Also, the q says 'the problem of using antibiotics,' in the case of viruses we're not using antibiotics in the first place.

THATS WHAT I THOUGHT BUT THN I THOUGHT THE MARKING SCHEME WUD BE RIGHT

 

[Hskk]

THATS WHAT I THOUGHT BUT THN I THOUGHT THE MARKING SCHEME WUD BE RIGHT

Which year is it? Maybe the examiner report says something...

 

[AhsanAfzal]

C is correct. Antibiotics can select resistant bacteria from a population with a diverse gene
pool, but cannot cause bacteria to become immune. Viruses are not affected by antibiotics.

my last comment was from examiner report

 

[AhsanAfzal]

why does it meet before retina. biology book by mary jones show that light converge at retina. Pls help.

 

[AhsanAfzal]

 

[HarithAslam]

why does it meet before retina. biology book by mary jones show that light converge at retina. Pls help.

because it never does. some weird clash b/w phy and bio but still, in bio light never converges at the retina; only a point before, so that a diminished, reversed and inverted image forms on the retina.

 

[HarithAslam]

anybody know o/n 2012 p12 q 37
about the homogeneous bacteria?
Bio

 

[AhsanAfzal]

because it never does. some weird clash b/w phy and bio but still, in bio light never converges at the retina; only a point before, so that a diminished, reversed and inverted image forms on the retina.

u mean it is wrong in mary jones book?

 

[AhsanAfzal]

anybody know o/n 2012 p12 q 37
about the homogeneous bacteria?
Bio

post link

 

[HarithAslam]

post link

http://papers.xtremepapers.com/CIE/Cambridge International O Level/Biology (5090)/5090_w12_qp_11.pdf

 

[Hskk]

my last comment was from examiner report

No wonder I didn't get the first part of it
Oh well, I hope this q doesn't come in my paper.