AS Level Biology; post your doubts!!

[slisjunknown]

Since A2 Biology is tough, there are less doubts for this part (AS) in the other threads...
so, if u guys have any problems, be free to share it and we'll try solving together

 

[slisjunknown]

Hi everyone..I've got a doubt
Which pair of organelles has internal membranes?
A chloroplasts and mitochondria
B chloroplasts and nuclei
C mitochondria and ribosomes
D nuclei and ribosomes
The correct answer is A..but, oughtn't it supposed to be B?
I need an explaination plss

 

[The Sarcastic Retard]

Since A2 Biology is tough, there are less doubts for this part (AS) in the other threads...
so, if u guys have any problems, be free to share it and we'll try solving together

The thread has already been created. Post your doubt there, hope you will answered with your satisfactory.

 

[Mantis]

A good resource for info on Biology A-levels can be found here:

http://www.alevel.co.uk/a-level-biology/

Its also very good in terms of career aspirations studying biology.

 

[IGCSE MAN]

In a certain organism, two traits are determined by two pairs of alleles, each of which shows dominance. One trait is determined by some combination of the alleles A and a. The other trait is determined by some combination of the alleles B and b, which are located on a different chromosome from A and a. Construct a complete Punnett square to show the results of a cross between two parents with genotypes Aabb (parent #1) and AaBb (parent #2). Then determine each of the following:

a) What fraction of the offspring is expected to have the same genotype as parent #1?
b) What fraction of the offspring is expected to have the same phenotype as parent #2?
c) What fraction of the offspring is expected to be dihybrid?

Please help me, i have a test tmmw!!! if possible please mail me the answer at [email protected]

 

[slisjunknown]

Can someone check out q15 and q21 in this paper
http://papers.xtremepapers.com/CIE/...and AS Level/Biology (9700)/9700_s07_qp_1.pdf
Pls help

 

[lara dalal]

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

 

[My Name]

Can someone check out q15 and q21 in this paper
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s07_qp_1.pdf
Pls help

Do you need the explanation or you got it ?

 

[nehaoscar]

Hello. Can someone please show me how to calculate this? The answer is D
View attachment 52307

The total energy used by the plants is the energy stored + the energy lost
This equals 27000+3000 kJ/mol
So the percentage will be
energy-used/total-energy-supplied
= (27000+3000)/(1 x 10^6)
= 0.03
multiply this fraction by 100 to get percentage
= 3%

 

[nehaoscar]

Hi everyone..I've got a doubt
Which pair of organelles has internal membranes?
A chloroplasts and mitochondria
B chloroplasts and nuclei
C mitochondria and ribosomes
D nuclei and ribosomes
The correct answer is A..but, oughtn't it supposed to be B?
I need an explaination plss

Did you get an answer for this?
If yes can you explain it to me too cause Nuclei also have a nuclear envelope right?

 

[AbdelRahman Basha]

Need help in enzymes I can't solve its questions

 

[AbdelRahman Basha]

Need some tricks to solve it

 

[My Name]

Need help in enzymes I can't solve its questions

How about posting some questions as examples so it'll be easier for members to help you.

 

[Studydayandnight]

Can someone PLEASE, PLEASE explain this multiple choice question to me! The correct answer is D.

 

[nehaoscar]

Can someone PLEASE, PLEASE explain this multiple choice question to me! The correct answer is D.

The cell undergoes meiosis therefore it's a reduction division and the number of chromosomes is halved.
Since 2n=2
Then n=1
So after the division 1 chromosome is present therefore this rules out the options A and C.
Now after reduction division, gametes (sex cells) are produced which contain chromosomes with one chromatid only.
Therefore the answer is D (as B is shown to consist of 2 chromatids)

 

[Studydayandnight]

The cell undergoes meiosis therefore it's a reduction division and the number of chromosomes is halved.
Since 2n=2
Then n=1
So after the division 1 chromosome is present therefore this rules out the options A and C.
Now after reduction division, gametes (sex cells) are produced which contain chromosomes with one chromatid only.
Therefore the answer is D (as B is shown to consist of 2 chromatids)

THANK YOU!!!!!!

 

[Studydayandnight]

Could someone explain this multiple choice question to me? The correct answer is B.

 

[Studydayandnight]

Also, this question!

It's the 34th one, correct answer is D.

 

[Studydayandnight]

PLEASE HELP MEEEEE!!!!

 

[My Name]

PLEASE HELP MEEEEE!!!!

How about post your doubt here:
https://www.xtremepapers.com/community/threads/a-level-biology-post-your-doubts-here.9858/
^This thread is more active. :3