A level Biology: Post your doubts here!

[qwertypoiu]

Do we have to know about the chloride shift for AS??

 

[Mayarzawaydeh]

hi. can someone please explain as to why the answer is A?

 

[lara dalal]

Hello can someone please show me how to calculate this? The answer is D

 

[My Name]

Do we have to know about the chloride shift for AS??

I'm not sure which AS syllabus you're following but as per the 2016 one:

 

[Mahmood Magdy]

Do we have to know about the chloride shift for AS??

Nope you don't have to

 

[qwertypoiu]

View attachment 52304

hi. can someone please explain as to why the answer is A?

Think about it, if you zoom in more, do you see more cells?
Or do you see more when you're ZOOMED OUT?
Answer is, when you zoom in, you see bigger cells, not more!
At x4000 magnification, you might see only 3 cells let's say, but at x40 maybe you'll see hundreds!
So answer is A because it's the LEAST zoomed. Hope that makes sense

 

[qwertypoiu]

Hello can someone please show me how to calculate this? The answer is D
View attachment 52308

The energy green plants take in, and the ones it wastes, all initially MUST come from photosynthesis.
Therefore energy gained from photosynthesis = 27,000 + 3000 = 30,000 units
Total sun energy = 1,000,000 units
Percentage ratio thingy = 30,000/1,000,000 x100% = 3%

 

[qwertypoiu]

I'm not sure which AS syllabus you're following but as per the 2016 one:
View attachment 52310

Nope you don't have to

Thanks

 

[salma_69]

can someone explain to me this question Scribd q1 part b (ii)
P.S i didnt take chem AS

 

[malk mohamed]

please tips for p4 application part questions

 

[princess Anu]

which one is the nucleus? I see so many dots :
/

 

[princess Anu]

is there any diff b/w free nucleotide and triphosphate nucleotide?
and b/w metastasis and secondary tumours?

 

[princess Anu]

do we need to learn preparation of material for viewing under electron and light microscope for AS?

 

[My Name]

which one is the nucleus? I see so many dots :
/View attachment 52359

What paper is this ?
Well, you can mark one of them since it says show ONE nucleus. :3

 

[princess Anu]

What paper is this ?
Well, you can mark one of them since it says show ONE nucleus. :3

I don't remember
yeah, but which one?

 

[Mahmood Magdy]

do we need to learn preparation of material for viewing under electron and light microscope for AS?

Under LM yes you do, but EM you don't have to.

 

[qwertypoiu]

Under LM yes you do, but EM you don't have to.

But what exactly should we know? We just apply stain to color it right?

 

[princess Anu]

why not A?

 

[princess Anu]

why not A?

 

[Mahmood Magdy]

But what exactly should we know? We just apply stain to color it right?

Uumm yeah I think so, try checking Mary Jones Revision Guide textbook. She summarized everything we need to know for the practicals plus some tips and hints.