A level Biology: Post your doubts here!

[Amy Bloom]

Oct/ Nov P 53 Q 2 (b)(2) .......How to find the expected (E) values here ????......I found the first one by ..... ( 21+32+19+40) /4
giving me 28 as (E) for with tails ....but i don't know Why ....so concept plsss.....and also 2nd one ....???...

(*_-)..........
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w11_qp_53.pdf

Here u are:
If i did a mistake please correct me.

 

[Amy Bloom]

Hey guys...pls help me out wid dis multiple choice questn..
Q. Which of the following is translated completely?
i) AUGUGAUUAAAGAA
ii) AUGAUAUUGCCCUGA
iii) AGUUCCAGACUCUAA
iv) AUGUACAGUAACUAG
The answer given is. (ii) bt how?

There is no DNA sequence given in the question?

 

[lyuchenqujoy]

Hey guys...pls help me out wid dis multiple choice questn..
Q. Which of the following is translated completely?
i) AUGUGAUUAAAGAA
ii) AUGAUAUUGCCCUGA
iii) AGUUCCAGACUCUAA
iv) AUGUACAGUAACUAG
The answer given is. (ii) bt how?

for iii), the first codon is not AUG which is the initial codon and translation should start with AUG, so this one can't be the answer.
for i) the second codon is UGA which is called a stop codon. and in iv), the 4th codon UAA is also a stop codon.
Another stop codon is UAG which is not shown in this question~

Hope these are helpful..

 

[Malik777]

Guyz Any Guesses for May/June 2013 ?

 

[PhyZac]

http://papers.xtremepapers.com/CIE/...and AS Level/Biology (9700)/9700_w05_qp_4.pdf
http://papers.xtremepapers.com/CIE/...and AS Level/Biology (9700)/9700_w05_ms_4.pdf

This is the quetion paper and markscheme...! My doubt is in question 6 (b) , can any one write a proper answer...i dont understand how it is written in markscheme

 

[Amy Bloom]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w05_qp_4.pdf
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w05_ms_4.pdf

This is the quetion paper and markscheme...! My doubt is in question 6 (b) , can any one write a proper answer...i dont understand how it is written in markscheme

Explain how the human insulin gene is joined to the plasmid DNA.

The same restriction enzyme that was used to make sticky ends at either end of the cDNA human insulin gene is used to make sticky ends (complementary to sticky ends on cDNA insulin gene) on the plasmid. The insulin gene and the cut plasmid are mixed and the complementary bases in the sticky ends pair up. Ligase enzyme is used to reconstruct the sugar-phosphate backbone of the DNA for the gene to combine permanently to the plasmid forming the recombinant DNA.

If i did a mistake please correct me. Hope my answer helped. Good luck

 

[PhyZac]

Explain how the human insulin gene is joined to the plasmid DNA.

The same restriction enzyme that was used to make sticky ends at either end of the cDNA human insulin gene is used to make sticky ends (complementary to sticky ends on cDNA insulin gene) on the plasmid. The insulin gene and the cut plasmid are mixed and the complementary bases in the sticky ends pair up. Ligase enzyme is used to reconstruct the sugar-phosphate backbone of the DNA for the gene to combine permanently to the plasmid forming the recombinant DNA.

If i did a mistake please correct me. Hope my answer helped. Good luck

Jazaki Allah khairan, thank you so much!! May Allah grant you and your family Jannatul firdous, and May Allah bless you. Tht helped alot!! THanks

the thing is, i asked for 6(b) but

 

[Amy Bloom]

Jazaki Allah khairan, thank you so much!! May Allah grant you and your family Jannatul firdous, and May Allah bless you. Tht helped alot!! THanks

the thing is, i asked for 6(b) but

Ameen. but? I answered ur doubt right?

 

[PhyZac]

Ameen. but? I answered ur doubt right?

You answered question 5(b) which was another hard question too.

 

[Amy Bloom]

You answered question 5(b) which was another hard question too.

Oops sorry . I'll see that again and post the answer in a while, dw.

 

[Amy Bloom]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w05_qp_4.pdf
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w05_ms_4.pdf

This is the quetion paper and markscheme...! My doubt is in question 6 (b) , can any one write a proper answer...i dont understand how it is written in markscheme

Discuss the effects that variations in carbon dioxide concentration and light intensity have on the rate of photosynthesis.

As the concentration of carbon dioxide increases, the rate of photosynthesis increases (1) as carbon dioxide limits the process (1). This occurs when temperature and light intensity are optimum, during the day (1). The rate of photosynthesis depends on different wavelengths of light (1). As light intensity increases the rate of photosynthesis increases as light directly affects the process, for example, at full sun when light is saturated (1). However, the rate of photosynthesis decreases when other factors such as stomatal aperture and temperature(1), start to affect the process. At high light intensity some pigments may be damaged (1) and therefore cannot absorb light and cause electron excitation (1).
Again, if there is any mistake, PLEASE correct me. According to me this answers worths 8 marks. Hope it helped. =]

 

[PhyZac]

Discuss the effects that variations in carbon dioxide concentration and light intensity have on the rate of photosynthesis.

As the concentration of carbon dioxide increases, the rate of photosynthesis increases (1) as carbon dioxide limits the process (1). This occurs when temperature and light intensity are optimum, during the day (1). The rate of photosynthesis depends on different wavelengths of light (1). As light intensity increases the rate of photosynthesis increases as light directly affects the process, for example, at full sun when light is saturated (1). However, the rate of photosynthesis decreases when other factors such as stomatal aperture and temperature(1), start to affect the process. At high light intensity some pigments may be damaged (1) and therefore cannot absorb light and cause electron excitation (1).
Again, if there is any mistake, PLEASE correct me. According to me this answers worths 8 marks. Hope it helped. =]

Thank you sooooooooo much..! Jazaki Allah khairan, May Allah reward you for the help! May Allah have mercy on you and your family...! thans alot..!! Atlast i understood! Alhamdulilah

 

[Amy Bloom]

Thank you sooooooooo much..! Jazaki Allah khairan, May Allah reward you for the help! May Allah have mercy on you and your family...! thans alot..!! Atlast i understood! Alhamdulilah

welcome brother

 

[Ahmad Zaeem]

Here u are:
If i did a mistake please correct me.
View attachment 22793

Thanks....It helped alot....infact i learned a new thing that we may have to make a cross in such type of questions.....thanks again

 

[Amy Bloom]

Thanks....It helped alot....infact i learned a new thing that we may have to make a cross in such type of questions.....thanks again

Welcome. Actually, if u do crosses, try to remember the phen. ratios like 9:3:3:1 in the chapter inherited change especially where you have co-dominance these kinda things., saving u time during examinations day. If u r good at it and can do it quickly on exams day its okay... and Welcome

 

[bia awan]

Please Can someone find me the mark scheme of Oct nov 12 paper 51 and 53?

 

[bia awan]

PLeaseeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee hurrrryyyyyyy

 

[Kumkum]

Please Can someone find me the mark scheme of Oct nov 12 paper 51 and 53?

here u go
http://papers.xtremepapers.com/CIE/...nd AS Level/Biology (9700)/9700_w12_ms_51.pdf
http://papers.xtremepapers.com/CIE/...nd AS Level/Biology (9700)/9700_w12_ms_53.pdf

 

[bia awan]

here u go
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w12_ms_51.pdf
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w12_ms_53.pdf

THankyoooooooooooouuu

 

[Kumkum]

THankyoooooooooooouuu

not a problem