A level Biology: Post your doubts here!

[hassam]

u shud say crossing over in prophase 1 because most ov markschemes say prophase 1 apart from one duffer examiner who said metaphase 1

 

[hassam]

well....pleaseeee some on emake a thread for A2 BIOOO..........PLEASEEEEE.....I MEAN A STICKY THREAD....ITS A REAL MESS HERE.......

 

[omg]

http://www.xtremepapers.com/papers/...and AS Level/Biology (9700)/9700_s07_ms_4.pdf

qs.4 part a.
can smbddy explain me point 3: K channels close and the role of Ca ions here??????

 

[XPFMember]

well....pleaseeee some on emake a thread for A2 BIOOO..........PLEASEEEEE.....I MEAN A STICKY THREAD....ITS A REAL MESS HERE.......

aoa wr wb!

we have one : http://www.xtremepapers.com/community/threads/typical-a2-biology-questions.10965/

 

[omg]

pls pls pls can i get a note on the hazards and benfits of gene technology with specific examples??????????

 

[vibhas1]

What is the difference between qualitative, quantitative, semi-qualitative, and semi-quantitative analysis? or what are the separately? their definitions?

Think about food tests etc. You can test whether each solution has sugars, fats etc, but sometimes you can't measure the amount of fat/sugar in the solution, or sometimes you can just measure whether 1 solution has more or less than another, etc.

Qualitative is when you can just say 'X' has fat in it and 'Y' has fat in it. You can't say whether X or Y has more fat.
Semi-qualitative i.e. Benedicts, when you either measure the time taken to reach a particular colour i.e. red, or the mass of the precipitate/intensity of the colour, is when you can say 'X has glucose, and Y has glucose, but X has more glucose than Y'
Quantitative is when you can say 'X' has 3.04 grams of sugar, y has 1.84 grams of sugar.

Semi-quantitative is harder to define, i think its when you get an approximate value.

Hope you learnt something.

 

[namename]

Hey people, I got sum thing from ms that sounds contradicting to me.....

point 8 where it says speed increased by 50 times / 0.5 to 100... and why is that 50 times?

 

[confused123]

hi all, please tell me that what happens to a chromosome between the end of anaphase and the start of the next mitosis.

 

[lingo]

hi, im an AS student..im having problem to do p3 paper for bio...could you help me to inform prospective topic which will be tested in the coming examination..pls..i really need help..pls..

 

[confused123]

http://www.xtremepapers.com/papers/...and AS Level/Biology (9700)/9700_s06_qp_2.pdf
question number 4 a part. how is the magnification 30,000. i mean the width is around 12 cm, so in micrometers it will be 120000 right? divided by 0.5 um. gives 240,000 X .

tell me one thing that 1 cm = 1 into 10000, is this conversion correct?

 

[confused123]

http://www.xtremepapers.com/papers/...and AS Level/Biology (9700)/9700_s06_qp_2.pdf
Q.5 c part. how is the curve after the addition of competitive inhibitor lower then the previous curve drawn. plz try it

 

[confused123]

Please Describe the function of the endodermis in roots.

 

[smartangel]

Explain, using named examples, how mutation can affect phenotype. [7].this is from June 2006. can some one please give me a note on down's syndrome as it is required for this answer as stated in marking scheme...

 

[smartangel]

does anyone have good notes on selection and evolution?

 

[confused123]

please anyone? :|

 

[Hussnain]

What is the diameter of phagocytes?

 

[Hussnain]

http://www.xtremepapers.com/papers/...and AS Level/Biology (9700)/9700_s06_qp_2.pdf
Q5(d)

 

[Hussnain]

http://www.xtremepapers.com/papers/...and AS Level/Biology (9700)/9700_w05_qp_4.pdf
Q2(a)(b)

 

[confused123]

this has become a QUESTION thread only!!!!!!!!!!!!!!!!!!!!!

 

[Idolfanatic95]

What is the diameter of phagocytes?

Neutrophils have a diameter range of 9-10 micrometers, where as macrophages (being larger than neutrophils) are about 21 micrometers in diameter.