Biology As paper 1 help

[Sarah kh]

I don't understand q21 here http://papers.xtremepapers.com/CIE/...and AS Level/Biology (9700)/9700_w03_qp_1.pdf , the answer is B , can someone help pls?

 

[Sarah kh]

Can someone explain why q25 is A ? Is it because it's tomato plant so it will contain non reducing sugar and no starch? http://papers.xtremepapers.com/CIE/...and AS Level/Biology (9700)/9700_s08_qp_1.pdf

 

[Sarah kh]

In this paper question 27 answer is C http://papers.xtremepapers.com/CIE/...and AS Level/Biology (9700)/9700_s08_qp_1.pdf
While the same question in here question 25 answer is A is it because of the word potential?

 

[Sarah kh]

Please help in question 4 http://papers.xtremepapers.com/CIE/...and AS Level/Biology (9700)/9700_w08_qp_1.pdf
Answer is B

 

[6Astarstudent]

aphid collects sucrose from the phloem.
and sucrose is non reducing sugar, so after benedict test + hydrolysis will yield positive result.

 

[6Astarstudent]

it says RNA stop codon is UAG, meaning the base on the mRNA is UAG
the complementary DNA code that will form UAG is ATC
so if you insert a T between AC, the stop codon forms.
hence answer is B

 

[Sarah kh]

Thank you so much !

 

[Sarah kh]

Thank you!

 

[enchanted era]

Thank you so much !

you have done all the past papers?