AS Biology P1 MCQs Preparation Thread

[sahania]

 

[sahania]

 

[sahania]

 

[sahania]

 

[sahania]

need your help

 

[SalamH]

ppl pleez solve dis.and by da way has dis ques cum in recent pprs ( which year?)
compared with single ribosomes polyribosomes increase the efficency of protein synthesis because they enable
A ribosomes to bind to the endoplasmic reticulum
B different protein molecule to be made simultaneously
C each copy of the same protein to be made more rapidly
D more than one copy of MRNA molecule to be read at the same time
E many copies of the same protein to be made simultaneously from one MRNA molecule

PS so many colours just 2 ensure it doesn't go unnoticed

 

[aom]

wopss.. im sorry.. for Q16, i mean, why can't it be C? the answer is A though..
and for Q38, the answer is B..

oh ya its B i didn't c the part that says per unit mass.... sorry.... and u solve it by multiply the first column by the second column and then divide by the third column .... that 4 sure ... and for 16 i got no clue

 

[knightrider1994]

ppl pleez solve dis.and by da way has dis ques cum in recent pprs ( which year?)
compared with single ribosomes polyribosomes increase the efficency of protein synthesis because they enable
A ribosomes to bind to the endoplasmic reticulum
B different protein molecule to be made simultaneously
C each copy of the same protein to be made more rapidly
D more than one copy of MRNA molecule to be read at the same time
E many copies of the same protein to be made simultaneously from one MRNA molecule

PS so many colours just 2 ensure it doesn't go unnoticed

Answer is C ?
If yes than only one logic prevails. Polyribosomes consist of many ribosomes together. All these will attach to different parts of mRNA and thus translation to make proteins can be done rapidly.

 

[Casablanca]

Has anyone done Oct/Nov 2007?

If so, please turn your attention to question 2. It asks about where digestive enzymes are made (which I know from reading the course that are released from lysosomes). However, in the marking scheme, it shows the answer to be the rough ER.

Why? Are they actually made in the rough ER? It doesn't say so in my book. If someone knows, please help a brah out.

 

[SalamH]

doubt . sum1 plz clear
Which statement correctly describe homologous chromosomes?
A they are formed during meiosis
B they are held together by centromeres
C they are identical
D they carry the same gene loci

ans is D. Why cant it be C????????

 

[SalamH]

Has anyone done Oct/Nov 2007?

If so, please turn your attention to question 2. It asks about where digestive enzymes are made (which I know from reading the course that are released from lysosomes). However, in the marking scheme, it shows the answer to be the rough ER.

Why? Are they actually made in the rough ER? It doesn't say so in my book. If someone knows, please help a brah out.

k ,the ques asks where they are made not stored .since all enzymes are proteins in nature they are formed by proteinsynthesis. so ribosomes are invoved and dey r present in d rough ER

 

[littlecloud11]

doubt . sum1 plz clear
Which statement correctly describe homologous chromosomes?
A they are formed during meiosis
B they are held together by centromeres
C they are identical
D they carry the same gene loci

ans is D. Why cant it be C????????

It can't be C because the homologous chromosomes have the same gene loci but the genes present in those loci may be different.
Like, one may have 'T' while the other has 't'. They can have alternate forms of the same gene.

 

[SalamH]

Which statement is true of all enzymes?
A They r denatured at temp above 60 degrees (k its wrong coz not all enzymes)
B They catalyse the breakdon of large molecules into smaller one (its wrong as well coz they catalyse anabolic and catabolic reactions)
C They have active sites which can bind to only one kind of substrates (this is possible ryt?????????????)
D They reduce the amnt of energy required to start a reaction (ya correct)

ans is D , why cant t be C

 

[SalamH]

It can't be C because the homologous chromosomes have the same gene loci but the genes present in those loci may be different.
Like, one may have 'T' while the other has 't'. They can have alternate forms of the same gene.

Oh yeah tnx

 

[thu]

View attachment 12588

the net primary production is reduced by 10% after each arrow.
so from phytoplankton it's 1300, at herbivorous is 130, at carnivorous is 13, at small fish is 1.3, tuna is 0.13
so answer is A

 

[thu]

Which statement is true of all enzymes?
A They r denatured at temp above 60 degrees (k its wrong coz not all enzymes)
B They catalyse the breakdon of large molecules into smaller one (its wrong as well coz they catalyse anabolic and catabolic reactions)
C They have active sites which can bind to only one kind of substrates (this is possible ryt?????????????)
D They reduce the amnt of energy required to start a reaction (ya correct)

ans is D , why cant t be C

i think because it can also bind to other inhibitors. since it's saying one 'kind' not one 'shape'

 

[JulyMei]

oh ya its B i didn't c the part that says per unit mass.... sorry.... and u solve it by multiply the first column by the second column and then divide by the third column .... that 4 sure ... and for 16 i got no clue

Ok. Thanks.

 

[Ineedhelp]

http://www.xtremepapers.com/papers/...and AS Level/Biology (9700)/9700_w05_qp_1.pdf
questions 23,24 and 37.

 

[JulyMei]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w05_qp_1.pdf
questions 23,24 and 37.

Q23) tRNA code is same as DNA. Just replace U to T.. So, the answer is B.. tRNA: CCU UCC UUC UCG , DNA: CCT TCC TTC TCG

Q24) C is thymine because when uracil appears, thymine disappear. so, find the number which is near as thymine (30, 24, 33). Hence, answer is B. because only adenine will have number which is near to thymine.

Q37) answer is C. 1 anitibody has 2 antigen binding sites. So, even when it hydrolysed(at hinge region) the binding sites are still there.. Therefore, there's 2 binding sites.

Hope it helps.

 

[fathimaash]

hey some1 pls name all da double membrane organels