AS Biology P1 MCQs Preparation Thread

[Gémeaux]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s07_qp_1.pdf
please explain questions 3 and 4

Q3) E.R in the cells produces in general proteins and lipids (S.E.R. makes lipids and R.E.R synthesizes proteins) These are transported to the Golgi Apparatus that modifies, packages and sends them in *vesicles* to their destination. The membranous sacs mentioned are these vesicles, whose products are used both inside and outside the cell.

 

[raamish]

Yes the elastic fibres/elastin, do have the same function in blood vessels.
You may find the video at the following link helpful in understanding the DNA experiment: http://highered.mcgraw-hill.com/sit.../chapter14/meselson_and_stahl_experiment.html

thnx ill check it out. can u also tell me the different formulas to calculate tidal volume and ventilation rate and breathing rate?

 

[Gémeaux]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s07_qp_1.pdf
please explain questions 3 and 4

Q4) One division of stage graticule is of 0.1mm. This covers about 50 divisions of the eyepiece graticule. this means that this can be calibrated as 0.002mm per division. ( by the unitary method, i.e.
mm : divisions on eyepiece gr.
0.1 : 50
x : 1
so, x = 0.1mm/ 50 = 0.002mm)
After four hours, the pollen tubes grow, select the one horizontal i.e. parallel to the scale. This covers approx. 10 divisions, which means that this is
10 x 0.002 = 0.02mm grown in 4 hours.
using again the unitary method,
0.02 : 4
y : 1
y = 0.02/4 = 0.005 mm per hour.
Convert this into μm, answer comes A which is 5μm/h

 

[Haniya Khan]

THANKS A TON

 

[Gémeaux]

Need help with these questions, please.
http://www.xtremepapers.com/papers/...and AS Level/Biology (9700)/9700_s08_qp_1.pdf
Q 5, 18, 26, and 34.

http://www.xtremepapers.com/papers/...and AS Level/Biology (9700)/9700_w08_qp_1.pdf
Q18

 

[Gémeaux]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w11_qp_12.pdf
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w11_ms_12.pdf
q 19 and q 20 please

For 19th questn, visualize mitosis. focus on the spindle fibers at each stage. A is when they are forming that is during prophase. B shows no considerable change in their length so this is meta phase. C shows that the length is reduced.. this must be when chromatids are separated, the anaphase. this leaves D to be the telophase. Here centromeres are detached from spindle fibers as the fibers are now disappearing.

Q20) The DNA is double-stranded. total nucleotides will be divided equally among both the strands. so 6000 for each strand. one codon consists of 3 bases i.e. 3 nucleotides. so 6000/3 = 2000 complementary anticodons used in the process. one tRNA (with specific anti-codon) has one amino acid attached to it, therefore 2000 amino acids in the chain formed.

 

[Nibz]

Need help with these questions, please.
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s08_qp_1.pdf
Q 5, 18, 26, and 34.

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w08_qp_1.pdf
Q18

Q5.
Lysosomes have hydrolytic enzymes. So the activity would be highest in them. In D option, the peak of lysosomes is the highest.

Q.18
Mitotic cycle doesn't include interphase. So DNA replication doesn't count. Option 1 is not right for obvious reasons. So '2 only'.

Q26.
Cohesive tension forces increase during the day - fact. When cohesive forces between water molecules increase, more water is moved through the xylem, increasing the diameter of tree.

Q34. All the other options don't relate to emphysema. But since emphysema reduces the oxygen-carrying capacity of blood, the last option seems valid.

 

[raamish]

Q5.

Lysosomes have hydrolytic enzymes. So the activity would be highest in them. In D option, the peak of lysosomes is the highest.​

​

Q.18​

Mitotic cycle doesn't include interphase. So DNA replication doesn't count. Option 1 is not right for obvious reasons. So '2 only'.​

​

Q26.​

Cohesive tension forces increase during the day - fact. When cohesive forces between water molecules increase, more water is moved through the xylem, increasing the diameter of tree.​

​

Q34. All the other options don't relate to emphysema. But since emphysema reduces the oxygen-carrying capacity of blood, the last option seems valid.​

​

​

can u tell the different formulas to calculate tidal volume and ventilation rate and breathing rate? and what is the difference between tertiary and quaternary structure and what do hydrophobic interactions do?​

 

[Nibz]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w08_qp_1.pdf
Q18

'Not completely replaced' implies that they are not completely replicated. Hence when they are cultured without X, the cell division will stop eventually. Not immediately because there will be enough telemores to promote the division.
Once you know this condition, no other option seems valid but A.

 

[Nibz]

​

​

​

can u tell the different formulas to calculate tidal volume and ventilation rate and breathing rate? and what is the difference between tertiary and quaternary structure and what do hydrophobic interactions do?​

Tidal Volume is the volume of air inhaled per breath. There is no such formula, you can simply do the calculations from the graph given in the question.
So is the breathing rate. You divide the number of breaths by the time.

Both have the same bonding, but quaternary structure has more than one polypeptide chain. Whereas tertiary structure has only one.
Hydrophobic Interactions help in protein folding.

 

[raamish]

http://www.xtremepapers.com/papers/...nd AS Level/Biology (9700)/9700_w10_qp_11.pdf

need help in 18,22,16,14,2,5

 

[TSZ]

Hey cn any one help me
http://www.xtremepapers.com/papers/...nd AS Level/Biology (9700)/9700_w11_qp_11.pdf
Q 23
The ans. is B
http://www.xtremepapers.com/papers/...nd AS Level/Biology (9700)/9700_w11_qp_12.pdf
Q 14, Q.30 and Q.40. The answers are D, D and D respectively

 

[Amaryllis]

For 19th questn, visualize mitosis. focus on the spindle fibers at each stage. A is when they are forming that is during prophase. B shows no considerable change in their length so this is meta phase. C shows that the length is reduced.. this must be when chromatids are separated, the anaphase. this leaves D to be the telophase. Here centromeres are detached from spindle fibers as the fibers are now disappearing.

Q20) The DNA is double-stranded. total nucleotides will be divided equally among both the strands. so 6000 for each strand. one codon consists of 3 bases i.e. 3 nucleotides. so 6000/3 = 2000 complementary anticodons used in the process. one tRNA (with specific anti-codon) has one amino acid attached to it, therefore 2000 amino acids in the chain formed.

thanks alot ^_^

 

[HuN3yy !!]

18 Male bees are haploid. They develop from unfertilised eggs. Female bees are diploid.
Which statements are correct?
1 All male bees are genetically identical.
2 Male bee sperm cells are produced by mitosis.
3 New combinations of genes only occur in female bees.


A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3

Help plzzzzz !!!!!!!!

 

[Soldier313]

can someone please urgently help me with
qn paper: http://www.xtremepapers.com/papers/...nd AS Level/Biology (9700)/9700_s11_qp_11.pdf
ms: http://www.xtremepapers.com/papers/...nd AS Level/Biology (9700)/9700_s11_qp_11.pdf
qn 10 - why B and not D?
qn 11 - explanation pleaaaasee
qn 18 - why not A?
qn 25 - why not A?
qn 29 - why C and not A??

thanx so much and God bless!!!

 

[Jaf]

I've found a mistake in a question - I think.
Question # 39 :
http://www.xtremepapers.com/papers/...nd AS Level/Biology (9700)/9700_w10_qp_11.pdf
The answer is A according to the mark scheme.
But this is what the examiner report says (and honestly, it makes more sense than the answer):
"The percentage transfer between the Sun and producers was 1%, between the producers and primary consumers is 10%, between the primary consumers and secondary consumers is 20% and between detritus and decomposers is 80%."

I think there's quite a good chance that they've mixed up the letters in the question. Views?
This has already been discussed here but whoever is 'trying' to explain it has no idea what they're talking about.
Views?

 

[geek101]

I've found a mistake in a question - I think.
Question # 39 :
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w10_qp_11.pdf
The answer is A according to the mark scheme.
But this is what the examiner report says (and honestly, it makes more sense than the answer):
"The percentage transfer between the Sun and producers was 1%, between the producers and primary consumers is 10%, between the primary consumers and secondary consumers is 20% and between detritus and decomposers is 80%."

I think there's quite a good chance that they've mixed up the letters in the question. Views?
This has already been discussed here but whoever is 'trying' to explain it has no idea what they're talking about.
Views?

yep this question has officially proved to be wrong on the paper that was uploaded for this year!
the Y is actually X
the Z is Y
and X is Z

 

[Jaf]

yep this question has officially proved to be wrong on the paper that was uploaded for this year!
the Y is actually X
the Z is Y
and X is Z

'Officially'?

 

[geek101]

'Officially'?

huh, i mean.....for sure its wrong!

 

[Jaf]

^Where'd you get that? :O