A level Biology: Post your doubts here!

[kity way]

Can someone please help with this graph?? the answer is 0.45 but i dont get it

 

[A*****]

Can someone please help with this graph?? the answer is 0.45 but i dont get it

It is quite simple...
Same water potential of sucrose solution and cell sap means that at that point there will be no change in length i.e. the ratio initial length/ final length would be 1... so look for the corresponding value of concentration for the value 1 of the ratio
Hope it helped

 

[Unknown202]

i know its a simple question but i just want to know what is added(in 2016) or removed(from 2014) from AS biology syllabus

 

[A*****]

i know its a simple question but i just want to know what is added(in 2016) or removed(from 2014) from AS biology syllabus

For that, check the latest syllabus

 

[Unknown202]

For that, check the latest syllabus

this is accounting i want 9700

 

[A*****]

Ohh sorry...here u go

 

[qwertypoiu]

24 In an animal cell, which process is dependent upon cell surface area and which process is
dependent upon cell volume?
cell surface area cell volume
A carbon dioxide produced oxygen used
B glucose absorbed hormones detected
C hormones detected carbon dioxide produced
D oxygen used glucose absorbed
Ans:C

Hormones are detected by the receptors on membrane of the cell. So the greater the cell surface area, the bigger the number of receptors that can detect hormones. The amount of gases used/produced in respiration are dependent on cell volume, as the bigger the cell the more consumption/production.

 

[Ayesha Asif333]

Guys, How many peptide bonds will there be in a chain of 100 amino acids?

 

[Unknown202]

i need a help in this question

 

[A*****]

i need a help in this question

First of all, see how many stage micrometer's divisions are being covered by the radius...that is 1 whole division and some part of the other. To calculate that exactly note that it can be clearly observed that 50 eyepiece divisions are being covered and since 40 e.p.g divisions cover 1 s.m division, so 50 e.p.g divisions cover (1/40)x50= 1.25 s.m divisions. The actual radius will then be 1.25x0.1= 0.125 mm= 0.125x1000= 125 um. Applying the formula of area, the area would be π x 125 x 125 i.e. option C

 

[A*****]

Guys, How many peptide bonds will there be in a chain of 100 amino acids?

Won't they be 100-1= 99?

 

[Ayesha Asif333]

Won't they be 100-1= 99?

Yea I too think 99's the right ans...some say it's 50
Thanks

 

[A*****]

Yea I too think 99's the right ans...some say it's 50
Thanks

No 50 can not be the right answer bqz all the amino acids are linked with one another in a chain...just imagine 3 of them linking up so there will be 2 bonds bw them...similarly if there are 5 so 4 bonds will be present. In this way it is quite obvious that for 100, 99 bonds will be present...

 

[owl.over.the.world]

Hi! Is there any one who is doing AS/A Level Biology this Oct/Nov, and finished 9700/S3 paper 22?
I just want to find out what you answered in the first question, whether it was B, C, or D (image attached for reference). I don't remember whether the meristematic region was in zone C or D of the image in the question and I'm getting a bit anxious.
Thanks

 

[Astralgod]

anyone know what might come for Practical paper 34 As bio?

 

[kity way]

It is quite simple...
Same water potential of sucrose solution and cell sap means that at that point there will be no change in length i.e. the ratio initial length/ final length would be 1... so look for the corresponding value of concentration for the value 1 of the ratio
Hope it helped

thank u!!

 

[Deeksha Tamang]

plz explain why?

 

[A*****]

View attachment 62750
plz explain why?

Is it A?

 

[Deeksha Tamang]

Is it A?

yup bt can u explain why ??

 

[A*****]

yup bt can u explain why ??

From the table, this is the lowest magnification...lowest magnification means that the size of each cell will be the smallest and so the maximum number can be seen
The smaller the size of an object, the more of them can fit in an area of space