A level Biology: Post your doubts here!

[Amy Bloom]

I have a problem in drawing the tissues , but thanks that was a bit helpful

For tissues u just have to draw the outlines, like:

I'm sorry for not drawing neat lines coz i did this on paint. try to do one (by hand) take a photo and upload it, we'll see. Good luck
Hope i helped.
P.S: note its a low power diagram of dicot leaf.

 

[stareaj]

Oct november 2003 question 2
Which pair of organelles have an internal membrane
Why isn't the answer the one with nuclie

 

[stareaj]

Also can someone pls tell me all the formulas in genetics chp

 

[stareaj]

And may June 2004 mcq no 37 and 38 can somebody pls explain the answers

 

[Malik777]

Any One Having notes of infectious Disease??

 

[PhyZac]

Oct november 2003 question 2
Which pair of organelles have an internal membrane
Why isn't the answer the one with nuclie

which paper?

 

[PhyZac]

And may June 2004 mcq no 37 and 38 can somebody pls explain the answers

In question 37 about the immune system’s first line of defence against invading microorganisms,
A ingestion of the microorganisms by B-lymphocytes (this is wrong for sure, bcause B cell isnt for ingestion )
B ingestion of the microorganisms by phagocytes (this is the correct answer because this is the fisrt thing happens when microorganism invade)
C production of antibodies (This is wrong, even if it is part of the immune response yet it isnt the first thing, it takes time before a B cell recognise antigen , divide forming clones and produce antibodies)
D production of antigens (this is wrong for sure, antigens are part of invading microorganism not human)

38 Which group could be a single population? Answer is C, and the reason is due to the definition of population, which is all the organisms of same spieces lliving in same area at same time.
A all the animals and plants on an isolated island nope, this is a community
B all the birds counted in one day in a garden nope, this is all birds, not a specific spieces
C all the bacteria in a colony of Bacillus subtilis yes, all bacteria of the particular spieces
D all the insects occupying three hectares of farmland nope, this is all insect, not a specific spieces!

 

[dornam]

That link does not work...

Regarding CIE grade boundaries, A represents 80%, right? Do I have to take at least 80% in each of the 5 papers to take an A?

 

[Malik777]

C :S

PLEASE ANSWER
View attachment 22248

 

[daredevil]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_nos_ps_13.pdf

for a levels practical skills on biology

is this for paper 3 or paper 5?? i'm confused

 

[strangerss]

For tissues u just have to draw the outlines, like:
View attachment 22375
I'm sorry for not drawing neat lines coz i did this on paint. try to do one (by hand) take a photo and upload it, we'll see. Good luck
Hope i helped.
P.S: note its a low power diagram of dicot leaf.

where is the spongy mesophyll layer? Thank you so so much , ok I'll do that soon and upload it . Thanks again , really appreciate it

 

[Amy Bloom]

where is the spongy mesophyll layer? Thank you so so much , ok I'll do that soon and upload it . Thanks again , really appreciate it

And please, i forgot to tell you, do your layers (tissues) proportionately: Each layer of cells in your drawing must be proportionate as the layers are in the diagram provided, you get it?

There is no really spongy mesophyll layer here because there are no large intercellular air spaces in between. In the micrograph you can only see clearly the: cuticle, upper and lower epidermis, the vascular bundle, the palisade mesophyll layer.

u're welcome, sure do post em.

 

[Amy Bloom]

In question 37 about the immune system’s first line of defence against invading microorganisms,
A ingestion of the microorganisms by B-lymphocytes (this is wrong for sure, bcause B cell isnt for ingestion )
B ingestion of the microorganisms by phagocytes (this is the correct answer because this is the fisrt thing happens when microorganism invade)
C production of antibodies (This is wrong, even if it is part of the immune response yet it isnt the first thing, it takes time before a B cell recognise antigen , divide forming clones and produce antibodies)
D production of antigens (this is wrong for sure, antigens are part of invading microorganism not human)

38 Which group could be a single population? Answer is C, and the reason is due to the definition of population, which is all the organisms of same spieces lliving in same area at same time.
A all the animals and plants on an isolated island nope, this is a community
B all the birds counted in one day in a garden nope, this is all birds, not a specific spieces
C all the bacteria in a colony of Bacillus subtilis yes, all bacteria of the particular spieces
D all the insects occupying three hectares of farmland nope, this is all insect, not a specific spieces!

u're a boss thumbs up!

 

[Amy Bloom]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_nos_ps_13.pdf

for a levels practical skills on biology

is this for paper 3 or paper 5?? i'm confused

In my opinion its both. This is a teacher's guide to teach students about practicals in biology and how to deal with paper 5. Its a good thing, have a look at it.

 

[Amy Bloom]

Oct november 2003 question 2
Which pair of organelles have an internal membrane
Why isn't the answer the one with nuclie

Paper?

 

[Amy Bloom]

Also can someone pls tell me all the formulas in genetics chp

huh? there aren't formulae as such. As far as i remember, punnett squares are done. Is that u are talkin about?

 

[Amy Bloom]

Any One Having notes of infectious Disease??

I do but in hard copies. Tell me about the "Diseases" u wish to have notes according to the syllabus u're appearing 4.

 

[daredevil]

In my opinion its both. This is a teacher's guide to teach students about practicals in biology and how to deal with paper 5. Its a good thing, have a look at it.

oh okay... thanks

 

[Malik777]

I do but in hard copies. Tell me about the "Diseases" u wish to have notes according to the syllabus u're appearing 4.

For myb As biology. I need all the Recommended Diseases :/

 

[Amy Bloom]

For myb As biology. I need all the Recommended Diseases :/

Huh what's Myb? I'll try to do something for you. coz u knw, all my notes are on hard copies and have bits everywhere. so i have to compile and type. it would be easier if you tell me the specific diseases that ur syllabus requires. in which session are u taking part? Maybe they removed or added diseases which i did not study. check the diseases required in the chapter according to the syllabus and type it here.